Diesel engine

Richard Lamb wrote:


PS: thanks for remembering the harmonics thread, Robert. (:it was fun

I remember thinking(back then) that I wanted to take a real good look
a the engine installation on the new plane for harmonic reactions.

I even asked around and found someone who have an old variable speed
disco strobe for the job.

But the engine wasn't ready to run back then, and I forgot about it.
Until now.

Thanks.

Richard

Radio Shack has a strobe for about $20. It's cheap, and won't even give
an epiletic a fit, but it has variable timing and does flash. You just
won't be able to use it in direct sunlight. Wait 'till evening or find
an old barn?

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

In article , Ernest Christley wrote:
Another strobe that many people have in their shop is an automotive timing
light. You can wind a simple coil of a few dozen turns and put it in the
trigger clip. Then, any convenient signal source such as an audio signal
generator can be used to produce the timing signals.

good luck,
tom pettit



PS: thanks for remembering the harmonics thread, Robert. (:it was fun

I remember thinking(back then) that I wanted to take a real good look
a the engine installation on the new plane for harmonic reactions.

I even asked around and found someone who have an old variable speed
disco strobe for the job.

But the engine wasn't ready to run back then, and I forgot about it.
Until now.

Thanks.

Richard

Radio Shack has a strobe for about $20. It's cheap, and won't even give
an epiletic a fit, but it has variable timing and does flash. You just
won't be able to use it in direct sunlight. Wait 'till evening or find
an old barn?

Richard Lamb wrote:

Pete Schaefer wrote:


Heat is usually the big one. How you get rid of it is critical, of course.
Dave Driskoll (DH) can probably tell us all more about this. One of the
things that is really cool about the DeltaHawk engines is that they are
designed to be run continuously at max (pretty sure about this.....Dave, are
you there?). That's a lot of full-time horses.




That't what it takes for aircraft ops.


Pete is quite correct, dumping heat is major hurdle to continuous power
operations and unfortunately it is generally not as simple as adding
larger radiators or oil coolers. Extracting BTU's from the oil or
coolant is really the simple part of the problem. Getting BTU's from
the combustion chamber, through the cylinder sleeves, piston crowns, and
fire plates without cooking the coolant, your bearings, or any of the
aforementioned parts can be quite challenging.

As a simple example, the VW TDI uses an oil squirter to spray cooling
oil on the bottom of the piston. That system is designed to remove a
BTU's at a certain rate and remain in equilibrium, IE stable oil
temperature at a certain HP (this would be the maximum continuous HP).
If we decide to increase the max. HP we now have to remove more BTU's
with the oil to maintain a stable temperature, this means more oil needs
to be sprayed. Ok put a bigger orifice on the oil jet. Unfortunately
putting on a larger jet reduces oil pressure which is bad for the main
bearings, so in addition to the larger jet, we now need to put a larger
oil pump on the engine to give us the required oil pressure. Oops that
bigger pump uses some of the additional HP that you thought you were
going to get and now we repeat the process with a larger jet and oil
pump so we net out the HP we are really after. Ok now that we've go
that solved, we notice that all the extra oil flinging around in the
crank case is too much for our current ring pack and we need a new
design there for better oil control. This new ring pack will of course
mean more friction, less net HP, etc., etc., etc. (bang head here)......

As Pete commented, the DeltaHawk is rated for continuos duty throughout
its HP range (as are most aircraft engines), most automotive engines are
not. While there certainly have been a number of very successful
automotive conversions, all of the successful ones have been the result
of a significant engineering and test efforts (a program which I suspect
is probably not unlike developing an aviation diesel from scratch).


Dave Driscoll
DeltaHawk LLC

In charles.k.scott@
dartmouth.edu wrote:

I think it actually will fit in the back of my pickup (haven't taken
the time to measure yet), and as you know, we live right next to some
pretty dense woods. I could trundle it up to the logging landing
above us and run it all day without bothering anyone.

If it were me, I would try to pick up a used trailer and turn that into
my test stand. Then you won't be risking damage to your engine from
repeated loading/unloading operations every time you want to do some
testing. This assumes that you will want to use your pickup truck for
things other than a test stand.

run smoothly lean of peak. I need to be standing there in the howling
wind taking down readings at regular intervals throughout the testing.

You could get one of those surveillance camera setups that are
advertised in various places and mount it to read your instruments. You
would then be able to monitor them from the relative comfort of your
pickup cab.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

On Tue, 27 Apr 2004 14:15:28 GMT, wrote:

In article , Ernest Christley wrote:
Another strobe that many people have in their shop is an automotive timing
light. You can wind a simple coil of a few dozen turns and put it in the
trigger clip. Then, any convenient signal source such as an audio signal
generator can be used to produce the timing signals.

good luck,
tom pettit

But what's a fella to do with the flashing light? What are you
checking and what's it all mean?

I mean the engine's going to have this 74" diameter prop on it and
it's bound to vibrate some. How do you tell what's normal and what
isn't?

Corky Scott

On Tue, 27 Apr 2004 10:48:31 -0500, Dave Driscoll
wrote:

As Pete commented, the DeltaHawk is rated for continuos duty throughout
its HP range (as are most aircraft engines), most automotive engines are
not. While there certainly have been a number of very successful
automotive conversions, all of the successful ones have been the result
of a significant engineering and test efforts (a program which I suspect
is probably not unlike developing an aviation diesel from scratch).

Mostly really interesting information Dave, but your remark about auto
engines not being rated at continuous maximum power prompts me to ask
if it's time to repost that article I have that was written by an auto
engineer who ran the engine test cells at (not sure which major
manufacturer he worked for but it's in the article).

To synopsize, they beat those engines up pretty well, trying to blow
them. They plan to sell not just hundreds, or thousands of engines,
but millions of them. Selling an engine that turns out to have an
endemic problem would be catastrophic for sales. So they run them
literally for hundreds of hours at full throttle and peak rpm. That's
just one test.

None of the auto manufacturers can afford to neglect this kind of
engine development so every single one does these types of destructive
tests to make sure the engine can stand it.

So while the typical auto engine may not be designed to produce
maximum continuous power, they sure can do it.

Corky Scott

PS, I will repost the article if there is enough interest. I get
requests to do so about once a year.

I would like to see the article.


So while the typical auto engine may not be designed to produce
maximum continuous power, they sure can do it.

Corky Scott

PS, I will repost the article if there is enough interest. I get
requests to do so about once a year.




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On Tue, 27 Apr 2004 10:09:59 -0700, "Bryan"
wrote:

I would like to see the article.

As you wish.

Please note, the article below was published in Contact! Magazine some
several years ago when Mick Myal was the publisher. He's retired from
the magazine now but was at the head at the time of the article so I
left that part in. I've made some editorial comments here and there
in the text.

Corky

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."

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

My thanks to Mick Myal for his continued excellence in publishing his
magazine.

Corky Scott

wrote:

On Tue, 27 Apr 2004 10:48:31 -0500, Dave Driscoll
wrote:



As Pete commented, the DeltaHawk is rated for continuos duty throughout
its HP range (as are most aircraft engines), most automotive engines are
not. While there certainly have been a number of very successful
automotive conversions, all of the successful ones have been the result
of a significant engineering and test efforts (a program which I suspect
is probably not unlike developing an aviation diesel from scratch).



Mostly really interesting information Dave, but your remark about auto
engines not being rated at continuous maximum power prompts me to ask
if it's time to repost that article I have that was written by an auto
engineer who ran the engine test cells at (not sure which major
manufacturer he worked for but it's in the article).

To synopsize, they beat those engines up pretty well, trying to blow
them. They plan to sell not just hundreds, or thousands of engines,
but millions of them. Selling an engine that turns out to have an
endemic problem would be catastrophic for sales. So they run them
literally for hundreds of hours at full throttle and peak rpm. That's
just one test.

None of the auto manufacturers can afford to neglect this kind of
engine development so every single one does these types of destructive
tests to make sure the engine can stand it.

So while the typical auto engine may not be designed to produce
maximum continuous power, they sure can do it.

Corky Scott

PS, I will repost the article if there is enough interest. I get
requests to do so about once a year.




Corky,

I'm pretty sure I've read the article that you are describing in the
past and absolutely agree that testing in the automotive world is quite
severe. However, unless you happen to have access to those test
results, the true duty cycle of the engine is a unknown. There are a
number of very successful automotive conversions that are flying, and in
deference to your point, some of the them with fairly modest
modifications required for acceptable endurance. However, all of them
required some modification and then some serious testing to concretely
demonstrate their endurance. The thrust of my point was not to imply
that automotive engines cannot be successfully modified for use in
aircraft, they quite conclusively can, but rather to demonstrate some of
the challenges that can be encountered in making any required
modifications and what those modifications might be.

Given that the original poster in this thread was asking about the
converting an automotive diesel its perhaps appropriate to examine the
modifications that were made to the Thielert Centurion. The 1.7
Centurion is essentially a modified Mercedes engine, a product which is
certainly respected for endurance and reliability within the automotive
world. I have been told by Thielert representatives (and I'm going from
memory here) that the modifications included the crank, pistons,
injection system, oil pump, turbo, and obviously the reduction unit (not
what I would consider a short list and one that is certainly supported
by a cursory examination of the the engine). In addition, even with all
of these changes, the currently quoted TBR (replacement not overhaul) is
1000 hours (to be fair, they anticipate 2400 hours and I suspect that is
probably still a conservative figure). Personally, I think that the
Thielert engineers did a very professional job and from their published
data they have extensively validated their engine through testing..
However, this illustrates quite clearly the point that regardless of
pedigree, once modification of basic engine system begins it can get
quite complicated quickly.

Personally, potential commercial competition aside, I'd love to see the
original poster successfully convert a 10 cylinder VW diesel for
aviation. I think it would be a really cool project. I'd also do my
best as a citizen of the homebuilding community to help him do it safely
and successfully. That said, I've been down the path you're on
regarding your static test installation. If you're interested, shoot me
your e-mail with your number, I think I can save you some grief on that
project.

Dave Driscoll
DeltaHawk Engines LLC

On Tue, 27 Apr 2004 14:10:09 -0500, Dave Driscoll
wrote:

The thrust of my point was not to imply
that automotive engines cannot be successfully modified for use in
aircraft, they quite conclusively can, but rather to demonstrate some of
the challenges that can be encountered in making any required
modifications and what those modifications might be.

I understand.

The engine I'm attempting to use is the Ford 3.8L V6. This engine was
originally modified by David Blanton back in the early 70's. I
hesitate to mention his name because he got mired in controversy
towards the end of his life claiming really exhorbitant horsepower for
the engine as used in the airframe.

The 3.8 needs a different cam in order to develop the power it should.
You can also install Wiseco pistons which create a 9 to 1 compression
ratio. Some guys haven't changed the pistons and managed to fly
anyway.

My understanding is that the new V6, the 4.2, is capable of being used
as is, without any modifications, which means not changing the cam. I
don't know that for a fact, it was stated to me by Jerry Schweitzer,
who has built a number of Ford engines and flew behind the 4.2 in his
RV4. He knows more about the engines than I do.

The intake manifold needs some modification and the carburator should
have the McNeilly leaning block installed so you can lean out the
mixture as you climb.

Some guys use the original fuel injection and electronic ignition. No
one engine is modified in the same manner, it's part of the problem of
knowing what to do.

One thing that is or should be common is safety wiring all external
and some internal bolts so that they cannot back out.

Not everyone does this.

Corky Scott