Chevy LS2 and Trans??? any real issues besides weight

[MrV]

Hey guys i'm a new pilot that really wants to build his own craft. help
me with this one issue.

I want to use a chevy ls2 or ls7 as the power plant in my craft.
now looking at everything including the hp/torque curves i've decided
running the engine around 3100 rpm should give me around 250 hp with
good torque now getting that power to a propeller seems to be an issue.
I'm wondering besides weight would there be any real issue using the
associated transmission locked in gear maybe 3rd/4th/5th gear whichever
is just under 1:1.

it would seem the car tranny has been engineered to convert the engine
motion into the spinning i would need to propel the propeller. plus
running the engine at 3100 rpm it would prob last longer than i will.

the aircraft i want to design is a very cab foward design with a
pusher prop and the engine would be mounted approx mid craft.

i'm new at this and besides having an engineering background i really
have no exp building an aircraft so any opinions would be helpful

thanx

Mrv

[Bret Ludwig]

A car transmission is not a suitable propeller redrive, neither for a
car or a boat. Study marine practice carefully: it is the same duty
cycle, and after all, no one puts a Lycoming in a boat even though they
could afford to.

No sensible propeller for 250 hp is going to want to turn 3100 rpm.
The diameter of the prop sets its maximum RPM as the tips must be kept
below Mach 1. Probably, you are going to want about a 2:1 reduction.
With a Gilmer belt drive you need to be at exactly 2:1 or fairly far,
say 1.6:1 or 2.4:1, or it will hunt and skip teeth. With gears you will
want them ideally at prime number tooth counts, such as individual
teeth see each other only rarely, and very definitely not 2:1. This is
what caused the catastrophe known as the Continental Tiara.

Driveshafts are very problematic in aircraft drive applications, plus
which there are substantial negatives to pusher propellers.

You do not want to design a engine package _and_ an airframe. There
are more good airframes than engines, although admittedly many are
better built by factories (one wood design hawked by an arrogant son of
a bitch in Virginia who has never built an airplane himself comes first
and foremost to mind.) Most homebuilts are just not designed for 600+
pound power packages. Most people want smaller airframes, I think, for
lower materials cost and easier garage building, even if they are not
afflicted with the common brain disease pervading experimental
aviation, WSE. (Williamsport Spongiform Encephalitis-a disease where
the brain has cooling fins eroded in its surface, causing the victim to
think that 1939 lawn tractor technology is essential to flight.)

[Darrel Toepfer]

MrV wrote:

> Hey guys i'm a new pilot that really wants to build his own craft. help
> me with this one issue.
>
> I want to use a chevy ls2 or ls7 as the power plant in my craft.
<snip>
> the aircraft i want to design is a very cab foward design with a
> pusher prop and the engine would be mounted approx mid craft.
>
> i'm new at this and besides having an engineering background i really
> have no exp building an aircraft so any opinions would be helpful

LS1/2/6/
http://www.v8seabee.com
http://www.seabee.info/seabee_engine_conversions.htm
http://www.republicseabee.com/Corvette_Power.html

They did all the legwork and I've seen publishied aritcles in the
aircraft magazines in regards to the Corvette engine conversions...

[MrV]

Thanx for the reply, i actually messed up in my previous post. the
intended numbers are 3200 to 3500 rpm and the propeller spinning approx
2500 to 2700 rpm.


why isn't a car tranny good ? it seems to do just what i want for
years in millions of cars reliably? Isn't the mated transmission made
to convert the slightly oval engine rotation into the circular motion
nec. for the prop? and also damp vib?


now the belt drive u mention seems reasonable but i really really don't
want my engine spinning faster than 3500 rpm:

thanx again

mrv

[Capt. Geoffry Thorpe]

"MrV" > wrote in message
ups.com...
> Thanx for the reply, i actually messed up in my previous post. the
> intended numbers are 3200 to 3500 rpm and the propeller spinning approx
> 2500 to 2700 rpm.
>
>
> why isn't a car tranny good ? it seems to do just what i want for
> years in millions of cars reliably? Isn't the mated transmission made
> to convert the slightly oval engine rotation into the circular motion
> nec. for the prop? and also damp vib?
>
>
> now the belt drive u mention seems reasonable but i really really don't
> want my engine spinning faster than 3500 rpm:
>
> thanx again
>
> mrv
>

The car transmission is not designed to run for hundreds of hours at high
loads in a lower gear. Lower gears in a car only accumulate tens of hours
over the life of the car. Plus you will be hauling a lot of excess iron
/aluminum around - excess weight is just about the last thing one needs in
an aircraft unless the intent is to minimize performance...

Slightly oval motion ot circular motion??????? It's just gears.

Damp vibrations? Not from a prop...

--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail
Spell checking is left as an excercise for the reader.

[MrV]

truthfully the idea is to make an OKAY craft. i'm thinking 150 to
160kts with okay fuel burn.
now if i'm right i'd be running the tranny in like 4th gear. isn't
this where its designed to spend a good deal of its time ?

if i remember right, a car engine's output is not perfectly circular
its kinda eccentric. and something is neccessary to convert the
irregular motion into the circular motion for the prop

[Capt. Geoffry Thorpe]

"MrV" > wrote in message
oups.com...
> truthfully the idea is to make an OKAY craft. i'm thinking 150 to
> 160kts with okay fuel burn.
> now if i'm right i'd be running the tranny in like 4th gear. isn't
> this where its designed to spend a good deal of its time ?
>
> if i remember right, a car engine's output is not perfectly circular
> its kinda eccentric. and something is neccessary to convert the
> irregular motion into the circular motion for the prop
>

If you are thinking of the top gear in a trans with overdrive, the overdrive
isn't designed for high torques (read the owners manual - "do not tow
trailers in overdrive"). Plus it will speed the prop, not slow it down. If
you are thinking 4th out of 5 gears in the typical trans with overdrive,
then you have direct drive - not much pont in bolting on a trans just to get
out what you put in, eh?

The auto trans has everything you don't want and nothing you do. No gears
would be a better choice than the wrong gears.

The torque output is not exactly constant, but the flywheel damps most of
that out. A propeller, on the other hand generates torque pulses as it goes
by cowling and stuff - that can cause problems if you are trying to run a
drive shaft. Pusher aircraft are "worst case". Note that most piston engine
aircraft have the prop bolted right on the end of the crankshaft - nothing
required to account for the torque pulses from the engine (Ignoring the
cases where you excite the resonant frequencies of the prop).

--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail
Spell checking is left as an excercise for the reader.

[MrV]

actually i'm thinking 4th or 5th gear from a 6speed manual tranny.
from the LITTLE research i've done
3rd gear is like 1.43 and 4th is like 1.2 seems like a good range
3500rpm= 2400 prop rpm
or at 1.2 3250 rpm = 2700 prop rpm.

now wouldn't the prop vibs be less than the abuse the average tranny
takes from a daily drive ?

[Drew Dalgleish]

On Thu, 10 Nov 2005 15:01:46 -0600, Darrel Toepfer
> wrote:

>MrV wrote:
>
>> Hey guys i'm a new pilot that really wants to build his own craft. help
>> me with this one issue.
>>
>> I want to use a chevy ls2 or ls7 as the power plant in my craft.
><snip>
>> the aircraft i want to design is a very cab foward design with a
>> pusher prop and the engine would be mounted approx mid craft.
>>
>> i'm new at this and besides having an engineering background i really
>> have no exp building an aircraft so any opinions would be helpful

Car transissions aren't designed to take any thrust. I also suspect a
phenominon called P factor would twist the end off the tranny the
first time you started up the engine with a prop attached.

[Darrel Toepfer]

Drew Dalgleish wrote:
> Darrel Toepfer wrote:

> Car transissions aren't designed to take any thrust. I also suspect a
> phenominon called P factor would twist the end off the tranny the
> first time you started up the engine with a prop attached.

If you're going to snip out what I typed, then please remove the quote
reference to me as well...

[MrV]

now that would be an issue but one i would solve by attaching the
tranny to a "GearBox" attached to frame to take thrust pressuer and
that being attached to the prop. kinda similiar to a rear diff

[Bret Ludwig]

MrV wrote:
> now that would be an issue but one i would solve by attaching the
> tranny to a "GearBox" attached to frame to take thrust pressuer and
> that being attached to the prop. kinda similiar to a rear diff

You are trying to say "thrust bearing", I think.

Look over carefully a Soloy Allison fixed wing conversion.

Intuitively, turning a propeller is a smoother load than the diff on a
car. In reality it is not. It took the marine industry twenty or more
years to realize you could use a car ingine in a boat, but only if its
"native" conditions vis-a-vis those of heavy slow turning boat engines
were carefully looked at. Dedicated small boat engines for inboard use,
gas or diesel, have become a thing of the past as autoderivative (with
"automotive" meaning heavy truck as well as car) engines are used
exclusively up to almost 1000 hp today. The LyCon museum pieces have
been saved this fate by a confluence of arcane and arbitrary
certification requirements, legal paranoia induced by Wichita's long
misrule by drunks and bitch-ass widows, and physics-weight is
irrelevant in boats but critical in aircraft, and most autoderivative
engine cores are heavy.

[Bret Ludwig]

Morgans wrote:
<<snip>>.
>
> At every power pulse, the crankshaft winds up a little bit, and then unwinds
> while waiting for the next power pulse. This can be a very large problem,
> and can destroy a drivetrain. Aircraft engines get around it by making a
> very stout driveshaft, but even then, some engine prop combinations are
> plackered not to run at certain RPM's in continuous operations.
>
> Do some research. There have been tons written on the subject, and even
> though it does not make sense, driving a prop is way harder than a car
> wheel, and avoiding the resonate problems.

Actually, aircraft engines don't deal with it very well at all. Large
radials deal with it by having a high reciprocating mass, and the 65
Continental class of engine deals with it by low impulse and again a
high reciprocating mass, but geared light aircraft engines have been
largely troublesome. The Continental Tiara was a disaster and so was
the GO-300. The planetary gear case Lycomings were a little more
successful but they were also heavy.

A good "car" engine that is suitable for ski boat use is suited to
aircraft use if 1) any resonant peaks in its internal configuration are
figured out first, (the boat will do that!) 2) a proper drive is
selected and 3) propeller loads are transferred to the airframe from
the drive and not the engine itself. Dave Blanton had no torsional
resonance problems, although he was probably a little lucky, and
careful study of Kiekhaefer's marine I/O and the Soloy Allison fixed
wing conversion (which use Allison helo turboshafts, different from
their purpose built fixed wing cousins) will be helpful.

A good autoderivative engin package solves a lot of problems aviation
users have lived with for so long they don't consider them problems
anymore, such as a prop stoppage destroying the entire lower end of the
engine, and not being able to run the engine without a prop or test
club.

[Morgans]

"MrV" > wrote in message
oups.com...
> actually i'm thinking 4th or 5th gear from a 6speed manual tranny.
> from the LITTLE research i've done
> 3rd gear is like 1.43 and 4th is like 1.2 seems like a good range
> 3500rpm= 2400 prop rpm
> or at 1.2 3250 rpm = 2700 prop rpm.
>
> now wouldn't the prop vibs be less than the abuse the average tranny
> takes from a daily drive ?

Resonate vibration is the killer in the aircraft powerplant world.

At every power pulse, the crankshaft winds up a little bit, and then unwinds
while waiting for the next power pulse. This can be a very large problem,
and can destroy a drivetrain. Aircraft engines get around it by making a
very stout driveshaft, but even then, some engine prop combinations are
plackered not to run at certain RPM's in continuous operations.

Do some research. There have been tons written on the subject, and even
though it does not make sense, driving a prop is way harder than a car
wheel, and avoiding the resonate problems.
--
Jim in NC

[Morgans]

"MrV" > wrote in message
oups.com...
> now that would be an issue but one i would solve by attaching the
> tranny to a "GearBox" attached to frame to take thrust pressuer and
> that being attached to the prop. kinda similiar to a rear diff

Weight, weight, weight!
--
Jim in NC

[stol]

600 LBS,,,, Yea right........I fly a auto conversion several times a
week and it is doing fine. Don't get me wrong, it took ALOT of time to
think it through and several generations of cooling systems but,,,
boy is it a blast to fly now..

Ben
www.haaspowerair.com

[Morgans]

"Bret Ludwig" > wrote in message
>
> Actually, aircraft engines don't deal with it very well at all. Large
> radials deal with it by having a high reciprocating mass, and the 65
> Continental class of engine deals with it by low impulse and again a
> high reciprocating mass, but geared light aircraft engines have been
> largely troublesome. The Continental Tiara was a disaster and so was
> the GO-300. The planetary gear case Lycomings were a little more
> successful but they were also heavy.

Agreed. Part of the solution, is like I said, stout (read heavy)
crankshaft, along with, as you stated, high reciprocating mass.

Radial engines have stout cranks, plus massive master and slave rods.

> A good "car" engine that is suitable for ski boat use is suited to
> aircraft use if 1) any resonant peaks in its internal configuration are
> figured out first, (the boat will do that!) 2) a proper drive is
> selected and 3) propeller loads are transferred to the airframe from
> the drive and not the engine itself.

Part of that "proper drive" for boats also use a rubber coupling between the
engine and the transmission, outdrive, v-drive, or prop shaft. The entire
output from the engine turns the rubber, then the rubber turns the drive.
In this manner, there is no metal to metal connection of the engine to the
drive. Every one I have seen uses one, but I'll be damed if I can remember
what the correct name is, at the moment! <g> Old age, or time of night?

Those units tend to absorb part of the pulse energy, and leaves a way for
the torsional energy to dissipate. They do eventually wear out, and a new
one has to be installed. AMHIKT. Very careful alignment is key to the unit
lasting as long as it should.

One of the more modern solutions is use of a toothed rubber drive belt, to
slow down the prop, and allow for a prop shaft and bearings that can deal
with all of the loads the prop creates. It also allows the belt to flex and
isolate the prop from the engine. They are pretty efficient, and have a 200
hour or more life expectency.

> Dave Blanton had no torsional
> resonance problems,

Some would argue that! <g>
--
Jim in NC

[Morgans]

"stol" > wrote in message
oups.com...
> 600 LBS,,,, Yea right........I fly a auto conversion several times a
> week and it is doing fine. Don't get me wrong, it took ALOT of time to
> think it through and several generations of cooling systems but,,,
> boy is it a blast to fly now..
>
> Ben
> www.haaspowerair.com

I can't tell for sure, since you didn't include some of the original post,
but I think the 600 pounds was a ballpark figure, if the OP had used a V-8,
the full auto transmission, and another drive unit to take the prop loads,
as he suggested he would.

Don't get me wrong; I am an auto drive fan. (or supporter, at least) <g>
--
Jim in NC

[Charles K. Scott]

On 10 Nov 2005 12:41:25 -0800, "MrV" > wrote:

>Hey guys i'm a new pilot that really wants to build his own craft. help
>me with this one issue.
>
>I want to use a chevy ls2 or ls7 as the power plant in my craft.
>now looking at everything including the hp/torque curves i've decided
>running the engine around 3100 rpm should give me around 250 hp with
>good torque now getting that power to a propeller seems to be an issue.
> I'm wondering besides weight would there be any real issue using the
>associated transmission locked in gear maybe 3rd/4th/5th gear whichever
>is just under 1:1.
>
>it would seem the car tranny has been engineered to convert the engine
>motion into the spinning i would need to propel the propeller. plus
>running the engine at 3100 rpm it would prob last longer than i will.
>
>the aircraft i want to design is a very cab foward design with a
>pusher prop and the engine would be mounted approx mid craft.
>
>i'm new at this and besides having an engineering background i really
>have no exp building an aircraft so any opinions would be helpful

Mrv, you should understand that homebuilders have been thinking that
auto engines should work fine for airplane powerplants from the very
beginning of the homebuilt era.

Not only homebuilders, but a number of qualified aeronautical
engineers thought likewise and have tried through the years, with
varying degrees of success, to convert auto engines to spin
propellers.

Toyota actually managed to get a Lexus based V-8 conversion certified
with a Hamilton prop designed specifically for it. But they withdrew
the engine from the market without attempting to put it into any
airframes, other than the test bed.

There is absolutely nothing inherently wrong with almost any auto
engine's ability to run at aircraft flight power settings for a long
time. That fact has been proven for years. What IS a problem is
fabricating a reliable prop speed reduction unit, and managing to
engineer adaquate cooling for the engine.

The litanny goes, it's not the auto engine that fails, it's everything
else. And there is a lot of everything else that can go wrong and
stop the prop from spinning.

From an aviation stand point, using an auto transmission for a PSRU is
not a great idea. For one thing, it's carrying around a bunch of
gears that add to the weight and aren't being used. That's just
crazy. Also, with the transmission in the car, the drive train is
locked solidly in place and does not impose any side loads to the
transmission at all. All it does is transmit torque as it spins.

But the propeller produces ENORMOUS side loads on the prop drive every
time you turn, hit turbulence or climb or dive. The auto
transmission, as it comes from the car manufacturers simply is not
designed to withstand that kind of side loading.

As mentioned previously, the lower gears in the transmission are
designed to be operated for only short periods. They do not have the
heft and thrust bearing support to manage sustained pressure at high
torque loads.

Finally, while belted PSRU's are fairly well understood at this point,
they tend to be marginal for high output engines. The only PSRU I'd
recommend at this point would be the Geschwender type. See:
http://www.alternate-airpower.com/ for details.

Corky Scott

[stol]

I can't tell for sure, since you didn't include some of the original
post,
but I think the 600 pounds was a ballpark figure, if the OP had used a
V-8,
the full auto transmission, and another drive unit to take the prop
loads,
as he suggested he would.

Don't get me wrong; I am an auto drive fan. (or supporter, at least)
<g>
--
Jim in NC



///////////////////////
Jim is correct there, It would weigh in at a ton....<g>

[Bill Daniels]

"Charles K. Scott" > wrote in message
...
> On 10 Nov 2005 12:41:25 -0800, "MrV" > wrote:
>
> >Hey guys i'm a new pilot that really wants to build his own craft. help
> >me with this one issue.
> >
> >I want to use a chevy ls2 or ls7 as the power plant in my craft.
> >now looking at everything including the hp/torque curves i've decided
> >running the engine around 3100 rpm should give me around 250 hp with
> >good torque now getting that power to a propeller seems to be an issue.
> > I'm wondering besides weight would there be any real issue using the
> >associated transmission locked in gear maybe 3rd/4th/5th gear whichever
> >is just under 1:1.
> >
> >it would seem the car tranny has been engineered to convert the engine
> >motion into the spinning i would need to propel the propeller. plus
> >running the engine at 3100 rpm it would prob last longer than i will.
> >
> >the aircraft i want to design is a very cab foward design with a
> >pusher prop and the engine would be mounted approx mid craft.
> >
> >i'm new at this and besides having an engineering background i really
> >have no exp building an aircraft so any opinions would be helpful
>
> Mrv, you should understand that homebuilders have been thinking that
> auto engines should work fine for airplane powerplants from the very
> beginning of the homebuilt era.
>
> Not only homebuilders, but a number of qualified aeronautical
> engineers thought likewise and have tried through the years, with
> varying degrees of success, to convert auto engines to spin
> propellers.
>
> Toyota actually managed to get a Lexus based V-8 conversion certified
> with a Hamilton prop designed specifically for it. But they withdrew
> the engine from the market without attempting to put it into any
> airframes, other than the test bed.
>
> There is absolutely nothing inherently wrong with almost any auto
> engine's ability to run at aircraft flight power settings for a long
> time. That fact has been proven for years. What IS a problem is
> fabricating a reliable prop speed reduction unit, and managing to
> engineer adaquate cooling for the engine.
>
> The litanny goes, it's not the auto engine that fails, it's everything
> else. And there is a lot of everything else that can go wrong and
> stop the prop from spinning.
>
> From an aviation stand point, using an auto transmission for a PSRU is
> not a great idea. For one thing, it's carrying around a bunch of
> gears that add to the weight and aren't being used. That's just
> crazy. Also, with the transmission in the car, the drive train is
> locked solidly in place and does not impose any side loads to the
> transmission at all. All it does is transmit torque as it spins.
>
> But the propeller produces ENORMOUS side loads on the prop drive every
> time you turn, hit turbulence or climb or dive. The auto
> transmission, as it comes from the car manufacturers simply is not
> designed to withstand that kind of side loading.
>
> As mentioned previously, the lower gears in the transmission are
> designed to be operated for only short periods. They do not have the
> heft and thrust bearing support to manage sustained pressure at high
> torque loads.
>
> Finally, while belted PSRU's are fairly well understood at this point,
> they tend to be marginal for high output engines. The only PSRU I'd
> recommend at this point would be the Geschwender type. See:
> http://www.alternate-airpower.com/ for details.
>
> Corky Scott

To me, it's interesting to note that in the automotive role, the engine is
isolated from the load to the maximum extent possible. In other words, the
engine is coupled to the wheels with cardan shafts that have U-Joints and
sliding splines such that engine vibrations, other than torque pulses, don't
get transmitted to the wheels and wheel vibrations don't get transmitted to
the engine. The engine just rocks and rolls in it's own rubber mounts and
transmits only torque to the drive line. The engine bearings see neither
thrust or radial loads. The vision is that everything is isolated with
rubber mounts to eliminate all possible vibrations. That seems to be a
successful formula for cars.

I'd suggest this is a good path to take in auto-engine conversions. Don't
just mount the prop to the crank or mount the PSRU rigidly to the engine.
Separate them and let the prop, PSRU and engine each live in their own
isolated vibration environment.

So, how to do this? First, think of a prop attached to the airframe turning
in it's own bearings that carry the thrust and radial loads with the bearing
carrier on elastomer mounts. Drive the prop with belts that absorb some
torque pulses and drive the belt with a pulley block mounted to the airframe
like the prop that is itself driven through a elastomer flex coupling by an
engine riding in isolation mounts. This way the prop won't see engine
vibrations and the engine won't see prop vibrations. The airframe itself
should see neither.

In drive line systems, there's no such thing as 'good vibrations'.

Bill Daniels

[[email protected]]

I've been around homebuilts and homebuilders since 1973, and have
learned much from the mistakes of others. The old guys will tell you
that you never design both an airplane and a powerplant at the same
time, and that you never design an airplane without training or
extensive research unless you are simply copying something else to a
great extent. I've met or read about fellows with odd ideas about some
"new" airframe who have either bankrupted themselves trying to make it
work, or nearly killed themselves trying to fly it. The majority of
these people weren't even pilots yet, just guys full of preconceived
notions. They spent an enormously frustrating amount of time and money
to no good purpose.
Auto engine adaptations are very time-consuming, and while
there are a few that run well enough, many of their builders wish they
had just bolted a Lyc to the firewall in the first place. Would have
been cheaper and they could have gone flying. I was also into boats for
some years, and knew a guy who did the auto transmission thing; didn't
last long at all. Those gears just won't take the high power levels for
very long. Cars don't cruise at 75% power, and that's all there is to
it. Detroit doesn't design stuff any stronger than it has to.
The OP would be wise to read EVERYTHING he can find on the
subject, which is a lot more than I had available in the '70s, what
with the 'Net and all. No excuse to make the same mistakes all over
again.

Dan

[Bret Ludwig]

wrote:
> I've been around homebuilts and homebuilders since 1973, and have
> learned much from the mistakes of others. The old guys will tell you
> that you never design both an airplane and a powerplant at the same
> time, and that you never design an airplane without training or
> extensive research unless you are simply copying something else to a
> great extent. I've met or read about fellows with odd ideas about some
> "new" airframe who have either bankrupted themselves trying to make it
> work, or nearly killed themselves trying to fly it. The majority of
> these people weren't even pilots yet, just guys full of preconceived
> notions. They spent an enormously frustrating amount of time and money
> to no good purpose.
> Auto engine adaptations are very time-consuming, and while
> there are a few that run well enough, many of their builders wish they
> had just bolted a Lyc to the firewall in the first place. Would have
> been cheaper and they could have gone flying. I was also into boats for
> some years, and knew a guy who did the auto transmission thing; didn't
> last long at all. Those gears just won't take the high power levels for
> very long. Cars don't cruise at 75% power, and that's all there is to
> it. Detroit doesn't design stuff any stronger than it has to.

The key is you want someone else to do the pioneering work for you.
Several autoderivative engine conversions have flown and proven to be
essentially sound. I would use one of them or at least study them
intently.

I felt at the time Blanton had essentially the right idea but should
have made his drive a two piece casting, making his own patterns and
having them poured at a nearby foundry and using automotive machine
tools to finish machine them quickly. Today I suspect a enclosed HyVo
drive or even gears-probably from an Allison truck trans-with a quill
shaft might be better. Only Blanton's pathological hatred for GM kept
him from real success in terms of volume-everyone else wants GM engines
because they are staplles of the hot rod industry.

[MrV]

As i stated earlier i'm an engineer and building/designing things is
something i burn to do. I've given myself 10 years to buid this thing.
My problem with airplane engines is cost they are far to costly for
what u get and are about as reliable as my lawnmower.

the tranny i'm talking bout is a chevy tremec tranny built for the
corvette. looking at the specs its about as bullet proof a gearbox as
anything i've ever seen.

now the tranny things is just an idea, use cheverolets billion dollars
of research to get something going. the only semi-const is the engine
which will more than likely be an ls2 as the ls7 i originally wanted is
up there with airplane engines in cost. well lower end airplane
engines. prob by the time i need the drivetrain it'll be cheaper.

the question is if the engine/tranny is isolated from the
thrust/sideloading/vib of the prop and besides weight would it be
reasonable to assume this would be okay. it really shouldn't be all
that difficult to completely isolate the drivetrain from the prop.


now some other details that i would like to get input on:

now the craft is essentially a kevlar covered steel tube frame. reason
being i'm good at welding but have worked very little with composites(
built speaker enclosures and spoilers for my car). but i really like
the finish of the composite aircraft. and kevlar because its cheaper
than graphite and lighter than fiberglass.

1. i only intend to run this thing at approx 50% power while i could
spin it up higher i just can't see a reason to do it. 400lbs for
200+hp seems like a good trade to me. Plus i can buy another one or
rebuild it myself for far less than the rebuild of an aircraft engine.

2. I"m not trying to build the most efficient fastest cruising thing
in the world. i want something reliable, simple kinda speedy(150 -
160kts) and without the prop, massive front end and massive instrument
panel infront of me.


3. 2 seater also maybe 3 but most likely 2.

4. also what is a good way to keep the sound of the engine/prop/gears
in back where it belongs ? massive noise in the cabin would completely
ruin the effect i'm trying to achieve.

hey guys i'm only hunting for ideas now so please feel free to respond
with anything u can come up with pro/con.

also hopefully you aren't annoyed hehe cause prob get realy frustrated
when i start asking about wing construction hehe.

[Bret Ludwig]

It has to be said also the fastest way into the air is indeed the
museum piece Lycoming engine-securely mounted to the firewall of an
already built certificated production aircraft. Even at today's high
prices, they still are a Good Deal for most people who really want to
fly.

[Morgans]

"MrV" > wrote:

A page displaying his total lack of knowledge.

To you, I put out the following possibilities. You are:

1) A kid playing on the computer. If I am wrong, stop using the text
message type of shorthand.

2) So completely ignorant of what works, what does not, and what might work,
that you need to get into the books, and/or Google, and do some homework.
The things you are proposing are ALL so far from reality, it is hard to know
where to start giving advise. I doubt you are going to get many responses,
because of this.

3) A plain and simple troll.
--
Jim in NC

[MrV]

yes i did and that is why i posted it here asking for comments. if u
notice a number of times i have stated this is just for info and if it
is reasonable. I'm guessing you are just an idiot that doesn't bother
to read complete post.

from the replies i've received the only thing i can see wrong with my
idea is 1 weight and 2 vibration everything else can be solved readily
with some planning. instead of posting something stupid like this why
not give reasons why i'm TOTALLY off base.

[Smitty Two]

In article . com>,
"MrV" > wrote:


> from the replies i've received the only thing i can see wrong with my
> idea is 1 weight and 2 vibration everything else can be solved readily
> with some planning. instead of posting something stupid like this why
> not give reasons why i'm TOTALLY off base.

I think cooling was mentioned also. And, those pesky details are not
trivial. I believe you also stated that your objection to Lycon is cost.
The knowledgeable people here have pointed out that you will spend *far*
more engineering your own airplane and powerplant than you would by
buying off the shelf. I don't think they're referring to percentage, but
orders of magnitude.

And then you alluded - in a somewhat mocking tone IMO - to some new
ideas you have for a wing. I think you can understand why it might be
easy for some of us to assume you're a troll. You might be some sort of
engineer, as you claim, but without the merest hint of any background in
aviation, that isn't going to buy you much in the real world.

Now, this is RAH, so I'm not going to suggest that you're off base. But
chatting here isn't research. Go spend several thousand hours studying
the issues, and then come back with *specific* questions based on a real
understanding. Even the Wright brothers started by learning everything
they could about what everyone before them had done.

I'll give you one "out." If your objective is to design the next Moller
skycar in order to bilk investors, then of course you don't need any
real understanding of the issues at all. That's an objective that
requires a completely different set of skills.

[[email protected]]

>from the replies i've received the only thing i can see wrong with my
>idea is 1 weight and 2 vibration everything else can be solved readily
>with some planning. instead of posting something stupid like this why
>not give reasons why i'm TOTALLY off base.

Why you're TOTALLY off base:
1. Weight. You do want to fly, don't you?
2. Design. You do want to live, don't you? Get some understanding of
aircraft. It can't be solved "readily."
3. Vibration. Kills mechanisms like you are proposing. Vibration is a
science all its own, and few there are that understand it.
4. Gyroscopic loads. We haven't even touched on that one yet.
5. Money. Hope you have lots to throw away. There are plenty of people
that will take it.
6. Reality. I can't recall anyone who entered this field, non-aviation
engineering background or not, that has designed a successful airplane
and powerplant combination from the ground up. Most of them crashed a
few times and learned from that; the rest died. Since there's lots of
info available now, there's no excuse to do the macho-ego-designer
thing anymore.
7. A Lycoming is a lot more reliable than a lawnmower engine. Witness
the average age of the lightplane fleet using them: something like 35
years?
We don't want another ignorant newbie killing himself and
discrediting the homebuilt movement. Please listen up.

Dan

[Bret Ludwig]

Smitty Two wrote:
> In article . com>,
> "MrV" > wrote:
>
>
> > from the replies i've received the only thing i can see wrong with my
> > idea is 1 weight and 2 vibration everything else can be solved readily
> > with some planning. instead of posting something stupid like this why
> > not give reasons why i'm TOTALLY off base.
>
> I think cooling was mentioned also. And, those pesky details are not
> trivial. I believe you also stated that your objection to Lycon is cost.
> The knowledgeable people here have pointed out that you will spend *far*
> more engineering your own airplane and powerplant than you would by
> buying off the shelf. I don't think they're referring to percentage, but
> orders of magnitude.

This assumes every user of a non-LyCon engine has to engineer his own
conversion from a clean sheet of paper. If you are going to apply that
standard you should insist every LyCon using homebuilder make his own
crankcase and cylinder patterns, pour sand castings himself, and
machine them. Instead of buying a reduction drive, mounts and so forth
pre-designed from a reputable supplier and attach them to an engine
core with good history of results, using plumbing and systems as other
successful operators have. That's the common sense solution. Find
someone making a redrive and mounts for a reasonable price, reflecting
only a small percentage for engineering since it's hardly a Skunk Works
project and amortizing it over many units.

The _best_ solution to auto engine cooling and cost is to buy a "real
aircraft engine" that is "proven". What does a new PT6A series P&WC
engine cost? That's a real aircraft engine, a LyCon is an overgrown
Volkswagen. Unfortunately, for me a new Pilatus PC-9 is outside the
range of affordability. (A L-39 is a third or fourth the price, and
that's too expensive by far for most of us.)

The sport boating industry exists to a large extent because of
affordable marinized auto-derivative engines and sport flying can use
them as well if some good simple engineering and common sense are
applied. In fact, it has, since the days of Bernie Pietenpol and Steve
Wittman, who flew reasonably well on commodity general purpose engines.

[Bret Ludwig]

Morgans wrote:
> "MrV" > wrote in message
> oups.com...
> > yes i did and that is why i posted it here asking for comments. if u
> > notice a number of times i have stated this is just for info and if it
> > is reasonable. I'm guessing you are just an idiot that doesn't bother
> > to read complete post.
> >
> > from the replies i've received the only thing i can see wrong with my
> > idea is 1 weight and 2 vibration everything else can be solved readily
> > with some planning. instead of posting something stupid like this why
> > not give reasons why i'm TOTALLY off base.

The guy isn't completely on the ball but he did ask a question that
has a simple and well-known answer. Car transmissions don't work in
boats either.

[MrV]

Hello Dan,

without saying so much i've already decided to sacrifice weight for
familiarity. considering the goal is to build a 2 seat aircraft i'm
pretty sure i can come in at an acceptable weight. no it will not be a
feather but should be reasonable considering the engine is aluminum.

i'm also trading weight for cost. the added cost of the approx equal
hp engine is a multiple of the cost of my auto engine.

now just quickly looking up a few things

O-360-A1D 180 284
O-360-A3A 180 285
IO-360-A1A 200 320
IO-360-B1B 180 295
IMO-360-B1B 225 274

GO-480-B1D 270 432
GO-480-G1D6 295 437
IGO-480-A1B6 295 469
IGSO-480-A1F6 340 498
O-540-A1A5 250 396
O-540-B2B5 235 395
O-540-B4B5 235 395
O-540-B4B5 260 398
IO-540-A1A5 290 437
IO-540-C4B5 250 402
IO-540-D4A5 260 402
IO-540-E1A5 290 437

compared to the 200hp io360 i give up 120 lbs to a tweaked out 360
engine acutally weighs about the same as a 540

now that doesn't take into account, radiator,coolant, associated
hardware, coils, alternators, etc. but some of that hardware is
common and would add to the weight of either engine.

i would estimate not giving up 200lbs at the same hp.


I haven't started building buying or even plotting out a time frame for
this project i'm jsut getting information at the moment formulating
ideas, plans and such. You guys actually seem to get threatened
maybe defensive what the hell.

number 6 i totally agree with and well already decided i'm willing to
take my risk. the thing i would fear more would be not trying.

no i don't have lots of money but i have enough to do what i want. In
reality the reason i chose the auto derivative is because i can INVEST
loads of time equity. i can tear down and rebuild a car engine how
much does that cost ? few hundred dollars in parts. now the lycoming
I CAN NOT WORK ON and the parts would cost more than the auto engine
probably. hell forget rebuilding i can buy a new engine for cheaper
than the cost of rebuilding a lyc.

I'm sorry bout the lycoming lawnmower comparison its not exactly true.
the briggs and straton is cheaper to repair. hehe JUST KIDDING.

the simple truth is I feel more comfortable with an auto engine. There
has not been 1 airplane mechanic i've spoken too that has said any
airplane piston engine is more reliable than a car engine. NOT ONE and
i've spoken to atleast 2 dozen of them since before i got my license.
that is not saying the car engine would be just as reliable in a plane
its just saying in their respective environments the airplane engine
has NOT shown any more reliability than the auto engine. also a few of
the mechanics stated they may be less reliable. NOT TROLLING THAT IS
WHAT THEY SAID

now 1 thing i would have u know I'm not a troll i'm not trying ****
anyone off just want ideas.

I want to know WHY an engine with nice rubber motormounts, tranny with
poly bushings between the tranny and SHORT drive shaft connected to a
thrustbearing secured to the frame would not live.

i'll state the conditions more clearly.

engine and tranny will run at a MAX OF 65% rated power. more likely
60%
they will not under any condition run above this power range. IN other
words at FULL OUT throttle wide open thign will spin at 3500 rpm if
that.

truthfully the idea of using the tranny as reduction unit was just that
an idea but now i want someone to explain to me where it will fail
given proper mounting and isolation.

[Morgans]

"MrV" > wrote in message
oups.com...
> yes i did and that is why i posted it here asking for comments. if u
> notice a number of times i have stated this is just for info and if it
> is reasonable. I'm guessing you are just an idiot that doesn't bother
> to read complete post.
>
> from the replies i've received the only thing i can see wrong with my
> idea is 1 weight and 2 vibration everything else can be solved readily
> with some planning. instead of posting something stupid like this why
> not give reasons why i'm TOTALLY off base.
>
I guess you can't read a whole post, either. I said before, that there are
so many problems, there is no good place to start the shooting down process.

Why don't YOU start by doing your homework, and do some research about what
is being done out there, and why some things are NOT being done.

Hint: If you start _without_ vibration and WEIGHT being solved, you can't
start. EVERYTHING will change, solving those problems.

Still haven't found the "shift" key, I see. It makes you look like a child,
or a lazy person. Maybe both.
--
Jim in NC

[Bret Ludwig]

MrV wrote:
> Hello Dan,
>
> no i don't have lots of money but i have enough to do what i want. In
> reality the reason i chose the auto derivative is because i can INVEST
> loads of time equity. i can tear down and rebuild a car engine how
> much does that cost ? few hundred dollars in parts. now the lycoming
> I CAN NOT WORK ON and the parts would cost more than the auto engine
> probably. hell forget rebuilding i can buy a new engine for cheaper
> than the cost of rebuilding a lyc.
>
> I'm sorry bout the lycoming lawnmower comparison its not exactly true.
> the briggs and straton is cheaper to repair. hehe JUST KIDDING.
>
> the simple truth is I feel more comfortable with an auto engine. There
> has not been 1 airplane mechanic i've spoken too that has said any
> airplane piston engine is more reliable than a car engine. NOT ONE and
> i've spoken to atleast 2 dozen of them since before i got my license.
> that is not saying the car engine would be just as reliable in a plane
> its just saying in their respective environments the airplane engine
> has NOT shown any more reliability than the auto engine. also a few of
> the mechanics stated they may be less reliable. NOT TROLLING THAT IS
> WHAT THEY SAID
>
> now 1 thing i would have u know I'm not a troll i'm not trying ****
> anyone off just want ideas.
>
> I want to know WHY an engine with nice rubber motormounts, tranny with
> poly bushings between the tranny and SHORT drive shaft connected to a
> thrustbearing secured to the frame would not live.
>
> i'll state the conditions more clearly.


Of course you could work on a Lycoming. There's no high magic, you
need a few tools like cylinder base wrenches and so forth, but if you
have the brains to work on any engine you can work on a Lyc, a Ranger,
a Menasco, a Napier Lion, an OXX-6, or any other museum piece.

All these engines have a place, like antique airplane fly-ins and,
umm, museums. (The last running Napier Lion is in a car. Go figure.)

First off though, you haven't done your homework. You didn't study the
available literature, and the successful projects that have flown.

Second, you should build an existing design first with an existing
engine setup. Several are available in varying states of compleness.
After you succeed at that, the piece de resistance can come later.

Third, you have a few Olde Pharts here. Some of them have advanced WSE
and some have apparently died, like Backdoor BoB, or whatever his name
was.

Second,

[Smitty Two]

In article . com>,
"MrV" > wrote:


>
> now that doesn't take into account, radiator,coolant,

You're going to put a radiator in a pusher? (Bret, wouldn't this qualify
as "clean sheet of paper" engineering? Or has this been done already?)

[MrV]

okay now from listening to u guys i've done just a bit of research.

check out http://www.epi-eng.com took a bit but i read most of this
site.

>From reading the epi site i've come up a couple new ideas.

instead of a single thrust bearing how about a double bearing system 1
for thrust and 1 to transfer gyro forces to frame and to isolate the
prop from the engine vibs . kinda like prop-|-|-engine. Also consider
the system will still have the flywheel in place.

actually i'd prob just buy a psru from epi considering they've already
created one specifically for the engine i plan to use.

..

[[email protected]]

>the simple truth is I feel more comfortable with an auto engine. There
>has not been 1 airplane mechanic i've spoken too that has said any
>airplane piston engine is more reliable than a car engine. NOT ONE and
>i've spoken to atleast 2 dozen of them since before i got my license.
>that is not saying the car engine would be just as reliable in a plane
>its just saying in their respective environments the airplane engine
>has NOT shown any more reliability than the auto engine.

I'm a mechanic, and I'll tell you: the engine/transmission setup you
are proposing is far less reliable than an aircraft engine. Most
direct-drive engine problems are electrical, and that means ignition
failure. Many auto conversions are single-ignition, relying on the
battery/alternator setup for power, and there have been problems.
Adding a second similar system doesn't increse safety much, since it
relies on the same power source and usually fires the same set of
plugs. Aircraft magnetos are a little less reliable than the auto's
system, but there are two of them, and two sets of spark plugs, making
the engine MUCH more reliable from the ignition standpoint.
That transmission will be heavy and will fail. It can't take
the high power levels for extended periods. When I put a Chev 283 in my
boat, I used a Warner marine transmission; it weighed about twice what
the chevy car trans had, and had only forward-neutral-reverse. It also
had a big oil cooler to keep it alive.
Your weight will be higher than estimated. These things have a
way of doing that. I have heard of several projects that came off way
too heavy to ever fly. Even the standard kit or plans-built airplane
usually ends up havier than forecast.

Dan

[Bret Ludwig]

wrote:
> >the simple truth is I feel more comfortable with an auto engine. There
> >has not been 1 airplane mechanic i've spoken too that has said any
> >airplane piston engine is more reliable than a car engine. NOT ONE and
> >i've spoken to atleast 2 dozen of them since before i got my license.
> >that is not saying the car engine would be just as reliable in a plane
> >its just saying in their respective environments the airplane engine
> >has NOT shown any more reliability than the auto engine.
>
> I'm a mechanic, and I'll tell you: the engine/transmission setup you
> are proposing is far less reliable than an aircraft engine. Most
> direct-drive engine problems are electrical, and that means ignition
> failure. Many auto conversions are single-ignition, relying on the
> battery/alternator setup for power, and there have been problems.
> Adding a second similar system doesn't increse safety much, since it
> relies on the same power source and usually fires the same set of
> plugs. Aircraft magnetos are a little less reliable than the auto's
> system, but there are two of them, and two sets of spark plugs, making
> the engine MUCH more reliable from the ignition standpoint.
> That transmission will be heavy and will fail. It can't take
> the high power levels for extended periods. When I put a Chev 283 in my
> boat, I used a Warner marine transmission; it weighed about twice what
> the chevy car trans had, and had only forward-neutral-reverse. It also
> had a big oil cooler to keep it alive.
> Your weight will be higher than estimated. These things have a
> way of doing that. I have heard of several projects that came off way
> too heavy to ever fly. Even the standard kit or plans-built airplane
> usually ends up havier than forecast.

Marine transmissions are much heavier for their complexity and power
than car transmissions, for good reasons, although most marine
transmissions are a little overdesigned-boats can handle the weight and
they are expensive, so no one minds.

Dual ignition is a good thing but compromising the integrity of
cylinder head castings for it isn't. Some car engines have two plug
heads but most of them are really heavy. The other thing is that most
combustion chambers in modern car engines are efficiently designed for
a single plug.

A serious IFR airplane using an autoderivative engine would have two
fully independent electrical systems withh two batteries and two
alternators, one of which would be a beltless type such as used on
MerCruiser Chevy IIs and sold to the circle track guys for years as an
"in the water pump pulley style", or some such. I think Rotax has such
a system on their "real aircraft engine", if that's still underway as a
project.

It's interesting to note Continental's FADEC engine-using a controller
far less sophisticated than MegaSquirt, the DIY FI system-which is
something like a $10K premium, gets rid of BOTH mags and gives you ai
internal one hour battery backup if the airframe electrics shoot craps
completely. My old spinster aunt ferried Bonanzas across the North
Atlantic in the early seventies and I'm sure she'd be glad to know that
if the electrics quit you had a whole hour!

[MrV]

Hey Dan good info. Question what is considered "High Load"? My plan
is to run the system at a max of 65%. from personal exp i know running
my auto at 5k rpm will shorten its life but i also know that it'll run
damn near forever at 3500 rpm.

One thing i had planned on was creating a duplicate electrical system
atleast up to the engine managment comp maybe even duel comps with
isolated elect buss. I would like to maintain the chevy ems but have
contemplated an after market. one thing i really really like about
the chevy ems is that when something goes bad say u lose a coil it
adjust and keeps running. My car lost one of the coils at about 60k
miles the only way i knew it was a loss of power and the service engine
light being on. I drove around like that for about a month before the
service guy told me the problem and replaced it. (side note -- never
ever let midas do this 700$ repair for 10 mins of work and 100 bucks
in parts)

I guess it may be a possible to have duplicate coil packs but just from
the examination of my auto that may be a bit difficult.

[Jim Carriere]

MrV wrote:
> Hey Dan good info. Question what is considered "High Load"? My plan
> is to run the system at a max of 65%. from personal exp i know running
> my auto at 5k rpm will shorten its life but i also know that it'll run
> damn near forever at 3500 rpm.

Question for you: What torque/rpm setting do you use to arrive at 65%?

Take a generic direct drive aero engine, and some ballpark figures for
the sake of an example to explain my question:

Let's say cruise flight is at 7,000 feet, wide open throttle, and near
max rpm. Max power is at sea level, wide open throttle, max rpm. More
numbers- let's say this cruise setting translates to 2,500rpm at 24".
Max power is 2700rpm and 29". Use some simple math and simplifying
assumptions (flat torque-rpm curve) about the engine to calculate
"percent" power...

2500/2700 x 24/29 = 77%

(pretty close to the popular definition of cruise power, 75%)

Anyway, just curious what numbers you use to get 65%. Note I don't have
any issue with the figure, I realize it's an arbitrary decision in
performance/reliability tradeoff.

By the way, the first hit on Google for keywords 'chevy ls2 rpm
horspower' gives 400hp at 5200rpm.

[GTH]

MrV a écrit :
> Hey Dan good info. Question what is considered "High Load"? My plan
> is to run the system at a max of 65%. from personal exp i know running
> my auto at 5k rpm will shorten its life but i also know that it'll run
> damn near forever at 3500 rpm.
>
>
Dear MrV (don't you have a real name ?)

As a lister from across the pond I can read English quite easily, but I
must confess that I am at a loss understanding your messages.
You must be posting with a cell phone, or something ;-)

I would like to say that it is wiser to state the exact mission of the
machine BEFORE starting to devise solutions to engineering problems not
yet existing.

What makes you thing a pusher is the best setup for the plane you intend
to design ?

Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr

[MrV]

well given sea level standard temp i'm looking at ~250hp at 3500 rpm
which from the graphs i've seen translates to about 360-375 lb-ft
torque at that point. now the graphs are few and far between but i'm
sure i can tweak it to atleast this level.

[MrV]

Hi Gth, the pusher is just a personal choice. The machine i envision
has nothing but glass/lexan/plexi and a few instruments in front of me.
No spinning prop, no front cowl.

now there are a number of current machines i like that almost fit.
notably the diamond models i did notice your plane looks similar to a
diamond. i really love the view from these craft and flying them is
almost where i want to go.

I just figured if i'm gonna hand build then try to shoot for the what
it is i really want and make compromises only when nec.

i kinda left it vague hoping people would rhyme in with any tho they
may have.

[Richard Lamb]

After building and flying a few airplanes you'll learn that weight is
the
MOST CRITICAL property there is in aviation.

Next comes harmonic resonance (well, in most auto mods anyway).

Richard

"One test is worth a thousand expert opinions"
Tex Johnston

[Richard Lamb]

Having read this far, I think Jim hit it right.
Kid playing with his computer.

-------------------------------------------------------
1 2 3 4 5 6 7 8 9 10
-------------------------------------------------------
^
|

Troll-O-Meter says try harder next time.

[Jim Carriere]

Morgans wrote:
> "Bret Ludwig" > wrote
>
>> gets rid of BOTH mags and gives you ai
>> internal one hour battery backup if the airframe electrics shoot craps
>> completely. My old spinster aunt ferried Bonanzas across the North
>> Atlantic in the early seventies and I'm sure she'd be glad to know that
>> if the electrics quit you had a whole hour!
>
> If I were going to ferry an airplane across the Atlantic that had a battery
> dependent ignition, I would throw in an extra battery; possibly a good 'ole
> deep discharge trolling battery.

One that would last as long as the fuel capacity, just as a matter of
principle. Or worst case, good for half of the trip :)

[stol]

Go peak at my website, www.haaspowerair.com and look close at all the
systems. The motor is all aluminum so weight is at a mininum, the
ignition is dual and totally independent from each other. I run a
Optima gel cell battery rated at 860 cca. The primary ign is powered
through the main buss, if it fails I can switch to ign #2. That is feed
straight from the positive post of the battery to only the # 2 MSD ign
box. The endurance of that battery will let me land and refill with
full fuel four times before the battery cannot provide enough power to
fire the plugs. Now, if I am dumb enough to land and not look into the
failure then I am deserve to be interviewed by the NTSB.......

Ben

[Morgans]

"Bret Ludwig" > wrote

> gets rid of BOTH mags and gives you ai
> internal one hour battery backup if the airframe electrics shoot craps
> completely. My old spinster aunt ferried Bonanzas across the North
> Atlantic in the early seventies and I'm sure she'd be glad to know that
> if the electrics quit you had a whole hour!

If I were going to ferry an airplane across the Atlantic that had a battery
dependent ignition, I would throw in an extra battery; possibly a good 'ole
deep discharge trolling battery.
--
Jim in NC

[Bret Ludwig]

stol wrote:
> Go peak at my website, www.haaspowerair.com and look close at all the
> systems.

Can I (or anyone) buy just the redrive? Are prices on the web? I
didn't see any list.

[Morgans]

"Jim Carriere" > wrote
>
> One that would last as long as the fuel capacity, just as a matter of
> principle. Or worst case, good for half of the trip :)

Ex-zacary! <BFG>
--
Jim in NC

[MrV]

Hey stol, question, what is the expected life of the belt in the
redrive? The only real experience i have with belted systems is in the
weighing systems we build for our industrial customers. I know belted
systems cause and transmit way less vibration to our platforms but
their life is far under the chains we used to use. Lucky customers
would get maybe 1 or 2 years out of a belt where as the the chains
never needed replacing. Miss treated systems would sometimes last
6mos.

Still the accuracy in weighing would far offset the cost of replacing
the drive belts so everyone is still happy.

also what is the cost of a belted redrive ? and where do i get the
high capacity belts when they need replacing ?

the only website i've read regarding the belted systems seems to
indicate belt manufacturers don't like this particular usage of their
products

thanx MrV

[Darrel Toepfer]

MrV wrote:

> also what is the cost of a belted redrive ? and where do i get the
> high capacity belts when they need replacing ?
>
> the only website i've read regarding the belted systems seems to
> indicate belt manufacturers don't like this particular usage of their
> products

http://www.beltedair.com

[stol]

Can I (or anyone) buy just the redrive? Are prices on the web? I
didn't see any list.

////////////////////////////////////////////////////////////////////////////////////////////////////////////////

The redrive is a BeltedAir unit I modified to fit on a Ford Block. They
are pretty damn stout units and all I needed to do was fabricate a new
block plate. I used all the other parts from the Chevy unit. I am sure
Jess@ BeltedAir has plenty in stock to fit Chevys.

Ben

[stol]

Hey stol, question, what is the expected life of the belt in the
redrive? The only real experience i have with belted systems is in the

weighing systems we build for our industrial customers. I know belted
systems cause and transmit way less vibration to our platforms but
their life is far under the chains we used to use. Lucky customers
would get maybe 1 or 2 years out of a belt where as the the chains
never needed replacing. Miss treated systems would sometimes last
6mos.


Still the accuracy in weighing would far offset the cost of replacing
the drive belts so everyone is still happy.


also what is the cost of a belted redrive ? and where do i get the
high capacity belts when they need replacing ?


the only website i've read regarding the belted systems seems to
indicate belt manufacturers don't like this particular usage of their
products


thanx MrV

////////////////////////////////////////////////////////

Your right, the manufacturers of those belts will ""NOT"" sell you one
if you even mention the application is closely related to aviation. Ya
just say is for a conveyor system or some other industrial setup. I
think the belts are somewhere around 70 bucks.

[[email protected]]

>well given sea level standard temp i'm looking at ~250hp at 3500 rpm
>which from the graphs i've seen translates to about 360-375 lb-ft
>torque at that point. now the graphs are few and far between but i'm
>sure i can tweak it to atleast this level.

It's that torque that will kill the transmission. No car,
especially a 'Vette, needs 360 ft-lb of torque and 3500 RPM to cruise
the highway, even at 90 MPH. Torque places a LOT of pressure on gear
teeth so that the friction heats them up, and the relatively high RPM
just multiplies the heating. And we haven't even discussed bearings
yet.
All that power in the car gets used to lay a strip of rubber a
few feet long perhaps a few dozen times in the car's life. More than
that, and the gearing starts to suffer. It's not used for cruising.

Dan

[[email protected]]

Thielert uses a belt redrive on its *certified* conversion designed
for the 172. Belts are OK. But like gears, they need some sort of
flywheel on the engine crankshaft to dampen the power pulses, or the
reciprocating lash will destroy them. The prop wants to turn at a
constant speed, while the crank lurches between compression and firing
strokes, and if the belt or gears are expected to deal with all the
difference they soon fail. Flywheels add weight, especially if they do
a good job of damping, and the redrive adds weight and more failure
points, which is why Continental and Lycoming and Franklin built mostly
direct-drive engines with long strokes and large cylinders to get the
torque required at lower RPM. Some radials were geared, as were the big
V engines, but the cranks were so massive and the cylinders numerous
enough that the engine ran smoothly enough without a flywheel.
Even a direct-drive engine can have problems with the lurching
effect of the crank. Some wood propellers, notably the Fairey-Reed
types used on larger recips, had to be regularly checked for proper
bolt torque and charring of the wood where it met the crank flanges.
Torque pulses were strong enough to cause movement.
I liked Geschwender's Hi-Vo chain drive in which lash was
minimized by the chain's teeth expanding as they bent around the gears.
Much stronger. That engine, I believe, was used in cropdusters like the
Pawnee rather successfully.

Dan

[Charles K. Scott]

On 13 Nov 2005 14:27:10 -0800, "MrV" > wrote:

>well given sea level standard temp i'm looking at ~250hp at 3500 rpm
>which from the graphs i've seen translates to about 360-375 lb-ft
>torque at that point. now the graphs are few and far between but i'm
>sure i can tweak it to atleast this level.

MrV, as others have indicated there are a lot of design issues that
make using an auto engine a lot more of an engineering problem than
you might think.

First and foremost, you really need to rethink the idea of using an
auto/truck transmission, even a Corvette tranny. It just doesn't make
sense from an engineering standpoint. It's WAY too heavy for the job
being required, and you are carrying around extra gears and shafts as
dead weight. Not only is it dead weight, it's weight kinda behind the
center of gravity. Plus, the gears you would need to use simply are
not up to the task of transmitting even 50% power, given that you are
talking about an engine capable of putting out 250+. Now that you are
talking about adding bearings to support and isolate the propshaft,
you are adding yet more weight, this time well behind the center of
gravity. Are your wings going to have the ability to swing forward
and aft in order to compensate for the different weights of the
pilot/passengrs and luggage?

There was a guy who tried really really hard to make a go of
installing the Buick/Olds 215CID aluminum V8 in the back of a Long
E-Z. Look for E-Racer on the internet. He kept blowing them up.
Some of the blowups were because he did not research in the hot rod
community about the engine. Had he done so he would have learned that
you cannot bore the engine out to 300 CID and go racing. That doesn't
leave enough material to support the cylinder sleeves. There were
many other problems that caused catastrophic engine failure. His name
is Shirl Dickey. He finally decided to install a Chevy V-6 and last I
heard, he'd yanked it and was using a Lycoming.

This is the setup you are talking about, except that you keep
insisting you can use an auto transmission too.

Driving a prop using a driveshaft has been done successfully before.
See Curtiss P-39 Airacobra and P-61 King Cobra. But the driveshaft
was MASSIVE, as was the engine (Allison V12).

It's admirable to want to build a quiet airplane but it is definately
not a trivial matter. Are you an aerodynamics engineer? If not, you
should be doing some extremely heavy reading to see what such will
take.

Ben Haas has a very clean looking auto engine conversion using an auto
engine. But he has a racing background and the engine is not a stock
unit. He had built a number of engines that raced, prior to
attempting to install something in his airplane. In addition, he did
not design his airplane, he left that headache to Zenith.

Others have mentioned that engineering an auto engine conversion is
not a simple task. Designing and building an airplane is REALLY not a
simple task. You are suggesting you want to do both.

I wish you the best of luck.

Corky Scott

PS, seeking information from this group is not necessarily a good
sign. As Groucho Marx put it, "I would not want to belong to any club
that would have me." ;-)

PPS, for those who think stock Detroit engines are not up to the task
of putting out a continuous 65% power, is it time again for me to post
the description of what one auto manufacturer does typically to test
it's engines? If you've never read it, you will be agast at the
punishment.

[MrV]

thanx charles it was just an idea to use the auto tranny.

just wondering if it would work so maybe just maybe i would have less
engineering work even considering the weight.

on a side note: does anyone have any hard numbers on the weight of an
Ls2 configured to run? I just spent an hour at an off road shop that
is selling me the engine and they say the shipping weight fully
configured is less than 300lbs. this is an off road racing optimized
ls2 i'm considering purchasing. 2 of us actually picked the thing up.
i really don't believe this but these guys build atleast 10 cars per
year.

btw good info charles.

hey can u post those test procedures i would really like to see it for
myself

[Morgans]

"Charles K. Scott" > wrote

> PPS, for those who think stock Detroit engines are not up to the task
> of putting out a continuous 65% power, is it time again for me to post
> the description of what one auto manufacturer does typically to test
> it's engines? If you've never read it, you will be agast at the
> punishment.

Yep, it's time, and this time, I'm going to save it, too. There is another
thread going somewhere else, about auto engines. It might be over in
RAPiloting.
--
Jim in NC

[[email protected]]

On Mon, 14 Nov 2005 18:36:12 -0500, "Morgans"
> wrote:

>Yep, it's time, and this time, I'm going to save it, too. There is another
>thread going somewhere else, about auto engines. It might be over in
>RAPiloting.
>--
>Jim in NC

Ok folks here it is in it's entirety, note, the comments in
parenthesis are sometimes mine. I originally posted this some five or
six years ago to this group:

Max Freeman is the engineer in charge of GM's Premium Engine programs
and has written an article for Mick Myal in the latest "Contact!"
magazine regarding the development and testing of their new PV6
aluminum 90° bank angle V-6. It's a lot of technical stuff about why
they chose this configuration or mechanical design over that, which is
why I like it.

He also wrote about the kind of developmental testing done on the
engine to make sure that customers get an engine they can depend on,
and I'd very much like to quote that section in full because it should
lay to rest the question of whether auto engines can take the kind of
power settings aircraft engines routinely manage.

"PERFORMANCE

The engine in production form for 1999 develops 215 HP at 5600 RPM and
230 foot pounds of torque at 4400 rpm. As a routine part of an engine
development program we tested the engine at full power, maximum RPM.
We ran it at 6000 RPM, pulling 215 HP at wide open throttle, for 265
hours. That's a continuous 265 hours of wide open throttle, far worse
than autobahn driving, because even on the German Autobahn, you
wouldn't be at 6000 RPM. THAT IS A STANDARD DURABILITY TEST.
(emphasis mine) We run many engines through this test as a matter of
course.

Specific development focus is on the crank, pistons, rods, block
structure, timing drive wear; we get a lot of full load cycles in a
hurry. It isn't necessarily designed to replicate customer driving
but to get development answers. Wear and fatigue are accelerated. The
test is particularly applicable in proving out dampers and their
effectiveness. If the damper is not properly tuned to the engine the
crankshaft will inevitably break in that time period. (note, this is
evidence you should not discard the stock damper when using the auto
engine for aircraft power)

A number of other engine tests are utilized. We use a variety of
specific tests to accelerate engine wear and to look at fatigue
failures. The cyclic endurance test is now called PTED (power train
endurance). It closely approximates cyclic durability. The engine is
cycled from its torque peak to its horsepower peak, at wide open
throttle, then down to idle, then accelerates up to shift points, then
back down to the torque peak and then horsepower peak. This test is
run for 400 hours. Once again, it's a wide open throttle test for 400
hours. The RPM for this engine, ranged between 4400 and 6000 RPM,
back and forth in about a 5 minute cycle. The dyno computer will
occasionally bring the engine down to idle, up to 6500 RPM shift
points, and then back to the 4400 - 6000 RPM 5 minute cycle.

Thermal cycle tests are run to define engine capability under cold
weather condition. We run the engine at full throttle at 4000 RPM,
bring it down to idle, stop it, switch the coolant valves to drain the
hot coolant, pump the chilled coolant from the chiller until the metal
temperature stabilizes at 0 degrees F. Frost forms on the outside of
the block, as the cold coolant rushes into the engine. When it
stabilizes at 0 F, we motor the engine, start it, come to full
throttle at 4400 RPM, the valves switch and the coolant temperature
starts to climb. It climbs back up to 260 degrees F. It takes 10 -11
minutes to complete one cycle. The engine must pass 600 cycles
without any sign of failure. We typically run 1200 cycles and a probe
test will run 1600 cycles. That's a (sic) excellent gasket killer
test. Head gaskets are the first to fail because of the rapid
expansion and contraction.

A powertrain endurance test simulates in-vehicle operation. The
Ypsilanti plant uses it for testing transmission. We, of course, use
it to look at engine performance. The equipment consists of an
engine/transmission combination, which sits on a dyno with large steel
inertia wheels. The inertia wheels are being driven by the
transmission output shaft, just like in a car. They cycle is brutal;
the engine is at idle in gear. The engine accelerates wide open to
6200 RPM, upshift occurs, 6200 RPM is reached, upshift occurs to 3rd,
6200 RPM is reached, upshift occurs to 4th, the wheels turn up to 135
MPH depending on the application. The second half of the cycle calls
for a closed throttle down to 70 MPH, then wide open throttle with a
downshift to 2nd, the engine goes back up to top speed, coasts down so
that the transmission selects down to a lower range. The engine is in
an overrun condition all the way down to idle; i.e., the engine is
being used for braking. That's one cycle. One transmission life
cycle is typically 12K - 13K cycles of the above test. We will run an
engine through 4 or 5 transmissions. This is a very harsh schedule
for the engine, particularly because of the overrun braking. Cylinders
and rings suffer the most on this test.

We run some idle tests to verify low speed operation. The engine is
run at idle for about 2000 hours to make sure of adequate oil flow at
idle.

We use all those engine tests in addition to fleet tests and extensive
vehicle road testing. The customer can be assured that the PV6 engine
is a thoroughly tested advanced design that matches or exceeds
competing offerings."

Corky's comment: I don't believe engine testing for aircraft
certification approaches this intensity, duration or severity.

[Charles K. Scott]

On 14 Nov 2005 13:21:23 -0800, "MrV" > wrote:

> just wondering if it would work so maybe just maybe i would have less
>engineering work even considering the weight.

1. It has been proven several times that it does not work. Even with
relatively low power engines, it doesn't work. It was tried using a
Honda Goldwing engine. Tranny failed after a while for all the
reasons cited previously. A more powerful engine would fail the
tranny, probably more quickly.

You do have a choice though, there are several businesses
manufacturing PSRU's built specifically for high power V-8's. The
afore mentioned Geschwender folks, and also Northwest Aero, they make
a psru for a high output Chevy, or used to.

So you do have the choice of bolting on a PSRU that you know will
work, thus negating at least that piece of engineering. You will
still have to think about the driveshaft, the coupling at both it's
ends, and all the issues that plague rear propped airplanes.

Corky Scott

[Montblack]

wrote)
> The engine must pass 600 cycles without any sign of failure. We typically
> run 1200 cycles and a probe test will run 1600 cycles. That's a (sic)
> excellent gasket killer test. Head gaskets are the first to fail because
> of the rapid expansion and contraction.


What's a probe test - that it needs to run 1600 cycles?


Montblack

[Bret Ludwig]

Charles K. Scott wrote:
> On 14 Nov 2005 13:21:23 -0800, "MrV" > wrote:
>
> > just wondering if it would work so maybe just maybe i would have less
> >engineering work even considering the weight.
>
> 1. It has been proven several times that it does not work. Even with
> relatively low power engines, it doesn't work. It was tried using a
> Honda Goldwing engine. Tranny failed after a while for all the
> reasons cited previously. A more powerful engine would fail the
> tranny, probably more quickly.
>
> You do have a choice though, there are several businesses
> manufacturing PSRU's built specifically for high power V-8's. The
> afore mentioned Geschwender folks, and also Northwest Aero, they make
> a psru for a high output Chevy, or used to.
>
> So you do have the choice of bolting on a PSRU that you know will
> work, thus negating at least that piece of engineering. You will
> still have to think about the driveshaft, the coupling at both it's
> ends, and all the issues that plague rear propped airplanes.

If I were determined to use a driveshaft there might be a good case
for putting the redrive at the prop end and having the driveshaft turn
at engine speed. This is done in some large turboprop installations,
there is a relativly long shaft.

Pusher props are really not that great an idea. Few successful designs
used them.

When I was in Europe, I saw a Fantrainer fly. What ever happened to
that airplane? I think it started with a recip and went to production,
such as it was, with an Allison turboprop.

[Bret Ludwig]

>
> Your right, the manufacturers of those belts will ""NOT"" sell you one
> if you even mention the application is closely related to aviation. Ya
> just say is for a conveyor system or some other industrial setup. I
> think the belts are somewhere around 70 bucks.

Don't tell them then.


But if I recall the Enstrom helo uses a Gilmer belt for main
transmission drive and oneother certificated helo had two or three of
them through the tailboom for tailrotor drive. I'm sure the
manufacturers knew.

[Charles K. Scott]

On Tue, 15 Nov 2005 12:42:50 -0600, "Montblack"
> wrote:

>What's a probe test - that it needs to run 1600 cycles?

Not sure what you mean by probe test. The article did not use that
description. My understanding is that it was a test to uncover
weaknesses in the engine when run hard in cold weather. It seems
suitably harsh to me.

Corky Scott

[GTH]

>
> Pusher props are really not that great an idea. Few successful designs
> used them.
>
>
Hi all,

Not sure if this was mentionned in recent posts.
Does this document ring a bell ?

http://ibis.experimentals.de/downloads/torsionalvibration.pdf

FWIW,

Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr

[Bill Daniels]

I noticed that the hot-rod crowd is using carbon fiber tubes for drive
shafts. The advantage is light weight, extreme stiffness and strength. I'm
not sure but this might reduce torsional vibration a lot.

Bill Daniels

"GTH" > wrote in message
...
>
> >
> > Pusher props are really not that great an idea. Few successful designs
> > used them.
> >
> >
> Hi all,
>
> Not sure if this was mentionned in recent posts.
> Does this document ring a bell ?
>
> http://ibis.experimentals.de/downloads/torsionalvibration.pdf
>
> FWIW,
>
> Regards,
> Gilles Thesee
> Grenoble, France
> http://contrails.free.fr

[[email protected]]

On Wed, 16 Nov 2005 08:16:00 -0800, Richard Riley
> wrote:

>I read your test description a long time ago, I agree it's very
>impressive. My impression is that the Sube guys are asking a lot more
>out of a lot less displacement than the V-6 guys. Any comment?

I don't know a whole bunch about what they ask of the Subie engines.
I've seen some engine companies that claim what seems to be excessive
power outputs and at pretty extreme engine rpms.

I never like holding an engine at or near it's redline for extended
periods, it just makes me very nervous. Four cylinder
Lycomings/Continentals et al seem to have extremely low redlines but
they also have large heavy pistons chuffing back and forth in very
large cylinders. The power each cylinder has to produce to get
(typically) 180 horsepower is about 45 hp. A typical automotive V6
needs to produce 30 horsepower per cylinder and a V8 only 22.5. Not
only are the combustion pulses lower, the reciprocating mass is lower.

That's why smaller engines can safely rev higher for longer periods.
But I still cringe when I see the kind of high rpms necessary for the
Subie's to produce the power they claim.

Corky Scott

[Montblack]

("Charles K. Scott" wrote)
>>What's a probe test - that it needs to run 1600 cycles?

> Not sure what you mean by probe test. The article did not use that
> description. My understanding is that it was a test to uncover
> weaknesses in the engine when run hard in cold weather. It seems
> suitably harsh to me.


Did so :-)

"The engine must pass 600 cycles without any sign of failure. We typically
run 1200 cycles and a probe test will run 1600 cycles. That's a (sic)
excellent gasket killer test. Head gaskets are the first to fail because of
the rapid expansion and contraction."

Was it a missing word, butchered sentence error, or is there a "probe test"
going on here?

(Here's the whole paragraph)
Thermal cycle tests are run to define engine capability under cold
weather condition. We run the engine at full throttle at 4000 RPM,
bring it down to idle, stop it, switch the coolant valves to drain the
hot coolant, pump the chilled coolant from the chiller until the metal
temperature stabilizes at 0 degrees F. Frost forms on the outside of
the block, as the cold coolant rushes into the engine. When it
stabilizes at 0 F, we motor the engine, start it, come to full
throttle at 4400 RPM, the valves switch and the coolant temperature
starts to climb. It climbs back up to 260 degrees F. It takes 10 -11
minutes to complete one cycle. The engine must pass 600 cycles
without any sign of failure. We typically run 1200 cycles and a probe
test will run 1600 cycles. That's a (sic) excellent gasket killer
test. Head gaskets are the first to fail because of the rapid
expansion and contraction.


Montblack

[Richard Lamb]

Copy that, Corky.

One thing that doesn't get discussed much is the idea of
direct drive auto conversions.

The VW is usually done that way, and I know of one V8 setup that
runs direct drive.

Quite a while back I sketched out a 7/8 scale Spad 13 that was
intended for a direct drive V6. The short nose on this plane makes
it possible - even necessary - to get some engine weight in there,
but this is an unusual case.

While the engine can't turn a prop fast enough to make _max_ hoss
power,
it probably could turn out something like 90 hp - with a 70 something
inch prop.
Which would be enough for the job, IMHO.

It's all about compromise, folks.

Maximize any one parameter and ALL the rest suffer immediately.

Compromise means carefully balancing all of the requirements.

Maximising horse power from an auto engine almost always means it
needs a PSRU (to turn a propeller) along with all the attendant weight,

harmonic issues, cost, complexity, and usually several single point
failure nodes.

But does the airframe _need_ that much power (need - not want - there's
a difference).

Can it stand the extra weight in the worst (ok second worst) place
(balance wise).

What does that extra weight do to the overall PERFORMANCE?
Wing area loading? Wing span loading? Stall speed - and stall
behavior?

Like it or not, (and FAA blessings aside) the aircraft engines we love
to hate
(or hate to love?)
evolved to fill that particular niche - and do it pretty well - all
things considered.

Compromise...


Richard

[Richard Lamb]

Sorry Bill, but I don't see how the drive shaft would (or could)
reduce engine vibration.

It _might_ reduce drive shaft harmonic responses.
Or it might actually increase harmonic responses.

Too many variables to call it without specifics.

But, in general, heavier parts respond to higher frequencies.

Lighter parts are more likely to respond to lower (closer
to engine frequencies.

Not much help today, am I...

Richard

[Bret Ludwig]

Richard Lamb wrote:
> Copy that, Corky.
>
> One thing that doesn't get discussed much is the idea of
> direct drive auto conversions.
>
> The VW is usually done that way, and I know of one V8 setup that
> runs direct drive.

Direct drive eliminates the many advantages of properly geared
installations, such as crank protection against prop impacts or
stoppages, the offset in crank to propeller line which enables the
engine to sit lower in the airframe, and the lower noise of slower
turning propellers. In many installations it is possible to start and
run the engine without a propeller attached, making maintenance and
troubleshooting easier.

[Jim Carriere]

wrote:
> On Wed, 16 Nov 2005 08:16:00 -0800, Richard Riley
>> I read your test description a long time ago, I agree it's very
>> impressive. My impression is that the Sube guys are asking a lot more
>> out of a lot less displacement than the V-6 guys. Any comment?

> That's why smaller engines can safely rev higher for longer periods.
> But I still cringe when I see the kind of high rpms necessary for the
> Subie's to produce the power they claim.

I don't think power to displacement ratio is the best or only comparison
between engines. The engine's ability to get rid of heat is an
important consideration, so is the strength of the crankshaft and
bearings (at least the weakest one, whether it's the journal, big-end
rod bearing, or even wrist-pin). Small engines, or small cylinders
anyway, have an inherent advantage for getting rid of heat, that's
geometry for you (volume and surface area don't increase at the same rate).

Also, just rpm doesn't tell the whole story. Piston speed (pretty much
rpm x stroke) is probably a better way of looking at it. Here's some
numbers:

Chevy LS-2 stroke 3.62" 400hp at 6000rpm 724 inches/second
Rotax 582 stroke 2.52" 65hp at 6500rpm 546 inches/second
Subara EA-81 stroke 2.64" 100hp at 5500rpm 484 inches/second
Pratt R2800 stroke 6" 2000hp at 2400rpm 480 inches/second
Rotax 912 stroke 2.4" 100hp at 5800rpm 464 inches/second
O-360 stroke 4 3/8" 180hp at 2700rpm 394 inches/second
Jabiru 3300 stroke 2.91" 120hp at 3300rpm 320 inches/second
Chevy (again) stroke 2.64" (derated) 3500rpm 308 inches/second

By the way, I have them in order of fastest to slowest piston speed. I
snuck in a few extra examples for fun. I don't have a TBO for the
Double Wasp :)

Of course, I don't think these comparisons tell the whole story either.
Food for thought though.

[Charles K. Scott]

On Wed, 16 Nov 2005 13:47:22 -0600, "Montblack"
> wrote:

>Did so :-)
>
>"The engine must pass 600 cycles without any sign of failure. We typically
>run 1200 cycles and a probe test will run 1600 cycles. That's a (sic)
>excellent gasket killer test. Head gaskets are the first to fail because of
>the rapid expansion and contraction."

When I transcribed the article originally, I put the (sic) in at that
point to denote that "a" is incorrect grammar in that sentence. It
should have been "an".

Corky Scott

[Charles K. Scott]

On 16 Nov 2005 14:24:21 -0800, "Richard Lamb" >
wrote:

>One thing that doesn't get discussed much is the idea of
>direct drive auto conversions.
>
>The VW is usually done that way, and I know of one V8 setup that
>runs direct drive.

In my opinion, a direct drive setup for an auto conversion should have
some kind of crank support bolted on to the engine block. Something
that basically becomes the drive flange and is designed to withstand
the kind of thrust loads that any propeller will apply to the end of
the crank.

If you look at direct drive engines built to turn props, the end that
has the prop flange usually has a very long bearing surface so that
the prop flange has support.

Auto engines aren't designed to have props bolted to the drive end,
they are designed to transmit power to a drive shaft that is supported
so that no side loads are imposed on the crank. That being the case,
the end bearing simply isn't adaquate to support a prop. In my
opinion.

I've seen bolt-on hubs that add this bearing support. At a minimum
I'd want one if I was to attempt a direct drive auto engine.

Replica fighters and pursuits are particulary good examples of
airplanes that require a heavy engine in order to properly balance the
center of gravity. WWI pursuits with liquid cooled engines had heavy
engines and not that much power. But they swung enormous props
compared to today's similar powered aircraft engines.

They often were redlined at only 1500 to 1800 rpm. The prop had to
have a large diameter and also have a wide cord in order to produce
the necessary thrust at those rpms.

In order to produce 180 hp at only 1800 rpm, given that they were very
low compression and unsupercharged, they had a large displacement.

Corky Scott

[Montblack]

>> "The engine must pass 600 cycles without any sign of failure. We
>> typically run 1200 cycles and a probe test will run 1600 cycles. That's a
>> (sic) excellent gasket killer test. Head gaskets are the first to fail
>> because of the rapid expansion and contraction."

("Charles K. Scott" wrote)
> When I transcribed the article originally, I put the (sic) in at that
> point to denote that "a" is incorrect grammar in that sentence. It should
> have been "an".


Ok. Good grammar catch.

Now, back to the probe test .....What is it?

Just curious - How is it different from the 600 or 1200 cycle tests that it
runs to 1600 cycles?

Am I dense?

(Here's the whole paragraph, again)
Thermal cycle tests are run to define engine capability under cold
weather condition. We run the engine at full throttle at 4000 RPM,
bring it down to idle, stop it, switch the coolant valves to drain the
hot coolant, pump the chilled coolant from the chiller until the metal
temperature stabilizes at 0 degrees F. Frost forms on the outside of
the block, as the cold coolant rushes into the engine. When it
stabilizes at 0 F, we motor the engine, start it, come to full
throttle at 4400 RPM, the valves switch and the coolant temperature
starts to climb. It climbs back up to 260 degrees F. It takes 10 -11
minutes to complete one cycle. The engine must pass 600 cycles
without any sign of failure. We typically run 1200 cycles and a probe
test will run 1600 cycles. That's a (sic) excellent gasket killer
test. Head gaskets are the first to fail because of the rapid
expansion and contraction.


Montblack
Former '89 Probe owner

[Bret Ludwig]

Richard Lamb wrote:

<<snip>>

> Like it or not, (and FAA blessings aside) the aircraft engines we love
> to hate
> (or hate to love?)
> evolved to fill that particular niche - and do it pretty well - all
> things considered.

That's just it. They have not evolved. They are like the coelecanth,
which lives, but only in an isolated world.

I have on my wall a picture of an early Bonanza with a woman standing
in the door. Most people do not recognize her, even though she is
perhaps the most famous woman in the world, even 43+ years after her
death. The point is if you went to A&P school when that picture was
taken, or when she died 15 years later, you could go out to the Beech
plant and see a A36 Bonanza and be essentially qualified to work on
every system. The engine would be almost identical except slightly
bigger. The ignition system is the same heavy high tension magnetoes,
as used on tractors and other farm equipment. The fuel injection
replaces the carburetor, biut it's the same old Hilborn style if they
are using Continentals. Lycs have the RSA system which was not invented
in 1946 but pretty well known in '62 if I recall correctly.

Can you imagine a young car mechanic of 1945 shown a 2005 automobile?

The coelecanth, a good name for the museum piece free air cooled split
case bolt-on-cylinder LyCon.

[Richard Lamb]

coelecanth, huh? I had to look that one up.
(And then I thought you were talking about me - not the engines! :^)

I'd be willing to bet that the reason this fish has remained unchanged
for a gazillion years is that it fits the enviornment perfectly - AND
the
enviornment that it fits so well has not changed either.

Your argument is, perhaps, that government regulation has created an
unchangable enviornment - causing stagnated development?

Can't argue much against that.

I flew a Rotax 912 a while back.
Tiny little thing that looks more like a toy than an aircraft engine.
But it runs very smoothly, turns a whopping big prop, and - all in all
-
seems to be a very sucessful engine.

If I could only afford one...


Richard

[Morgans]

"Charles K. Scott" > wrote

> When I transcribed the article originally, I put the (sic) in at that
> point to denote that "a" is incorrect grammar in that sentence.

What does the (sic) stand for? I have seen it, and understand what it is
trying to do, but never have heard what the root of the meaning is.
--
Jim in NC

[Montblack]

>> When I transcribed the article originally, I put the (sic) in at that
>> point to denote that "a" is incorrect grammar in that sentence.

("Morgans" wrote)
> What does the (sic) stand for? I have seen it, and understand what it is
> trying to do, but never have heard what the root of the meaning is.


http://www.askoxford.com/asktheexperts/faq/usage/sic

http://andromeda.rutgers.edu/~jlynch/Writing/s.html
From this link:

Sic.
Apart from necessary omissions and interpolations, your quotations should
always be exact, and any departures from the original should be clearly
indicated with ellipses or brackets.

Sometimes, though, you may have to quote something that looks downright
wrong. In these cases, it's traditional to signal to your readers that the
oddities are really in the original, and not your mistake. The signal is
"[sic]": square brackets for an interpolation, and the Latin word sic,
"thus, this way." (Since it's a foreign word, it's always in italics; since
it's a whole word and not an abbreviation, it gets no period.) It amounts to
saying, "It really is this way, so don't blame me."

George Eliot was a woman: if someone you quote gets it wrong, as in "George
Eliot's late fiction shows major advances over his earlier works," you might
signal it thus: "George Eliot's late fiction shows major advances over his
[sic] earlier works." Old spellings were often variable: if your source
spells the name Shakspear, you might point out with a [sic] that it really
appears that way in the original.

Don't use sic to show off with gotchas. Too many writers sic sics on the
authors they quote just to show they spotted a trivial error. If your
audience is unlikely to be confused, don't draw attention to minor booboos.
[Entry added 3 November 2000.]


Montblack

[StellaStarr]

Morgans wrote:
> "Charles K. Scott" > wrote
>
>
>>When I transcribed the article originally, I put the (sic) in at that
>>point to denote that "a" is incorrect grammar in that sentence.
>
>
> What does the (sic) stand for? I have seen it, and understand what it is
> trying to do, but never have heard what the root of the meaning is.

Always wondered. Thanks for making me look.
From UrbanDictionary.com:

Square brackets are most commonly used around the word 'sic' (from the
Latin 'sicut', meaning 'just as'), to explain the status of an apparent
mistake. Generally, sic means the foregoing mistake (or apparent
mistake) was made by the writer/speaker I am quoting; I am but the
faithful messenger; in fact I never get anything wrong myself.

And from reference.com:
When found in a French document, (sic) stands for "Sans Intention
Comique" (without comic intention) meaning that even if the preceding
text could be understood as funny, it was not meant to be (analogous to
"no pun intended" in English).

[AINut]

DANG! The seabee folks charge as much for their $6000 Chevy engine as
Lycoming does for their $3000 engine!

David M.


Darrel Toepfer wrote:

> MrV wrote:
>
>> Hey guys i'm a new pilot that really wants to build his own craft. help
>> me with this one issue.
>>
>> I want to use a chevy ls2 or ls7 as the power plant in my craft.
>
> <snip>
>
>> the aircraft i want to design is a very cab foward design with a
>> pusher prop and the engine would be mounted approx mid craft.
>>
>> i'm new at this and besides having an engineering background i really
>> have no exp building an aircraft so any opinions would be helpful
>
>
> LS1/2/6/
> http://www.v8seabee.com
> http://www.seabee.info/seabee_engine_conversions.htm
> http://www.republicseabee.com/Corvette_Power.html
>
> They did all the legwork and I've seen publishied aritcles in the
> aircraft magazines in regards to the Corvette engine conversions...

[Morgans]

"Montblack" > wrote

> The signal is
> "[sic]": square brackets for an interpolation, and the Latin word sic,
> "thus, this way." (

Somehow, I figured you would be the ones (sic) to straighten me's (sic) out.
Thanks!
--
Jim in NC