VW Reality

On Feb 10, 12:57 am, cavalamb himself wrote:
wrote:
On Feb 9, 2:10 pm, Anthony W wrote:

I was wondering about that too. The compression ratio doesn't seem high
enough to require that. Perhaps a thicker head gasket could be used to
lower the CR so it would run on auto-premium to make it cheaper to operate.
...

I once owned a McCulloch two-stroke four-cylinder drone
engine that had been modified this way to derate it from 72 hp to 50
and to allow it to run smoother at a lower RPM. Terrible engine,
commonly used years ago in Bensen's gyrocopters. They'd been built by
McCulloch for the military, who used them in target drones for anti-
aircraft gunners to practice shooting down, so the engine was designed
for a 15-minute service life or something like that. In homebuilts,
they vibrated like mad, and the mag would get hot and quit. The
carburetor throttle shaft would wear the thin carb barrel walls out in
no time flat and leak air. But cheap they were, light, and plentiful.
Couple pictures of one, and one of a Franklin drone engine, too:
http://www.barnstormers.com/EVENTS/0...museum-21.html

Dan

Perhaps, like teh VW, a spacer at teh bottom of the cylinder can be
used to adjust compression?

I know someone who added a third piston ring to his pistons.

He said he got 95 hp, didn't say for how long, and I don't think he
ever ran it full bore for very long.

--

FF

"Fred the Red Shirt" wrote in message
...
On Feb 10, 12:57 am, cavalamb himself wrote:
wrote:
On Feb 9, 2:10 pm, Anthony W wrote:

I was wondering about that too. The compression ratio doesn't seem
high
enough to require that. Perhaps a thicker head gasket could be used to
lower the CR so it would run on auto-premium to make it cheaper to
operate.
...

I once owned a McCulloch two-stroke four-cylinder drone
engine that had been modified this way to derate it from 72 hp to 50
and to allow it to run smoother at a lower RPM. Terrible engine,
commonly used years ago in Bensen's gyrocopters. They'd been built by
McCulloch for the military, who used them in target drones for anti-
aircraft gunners to practice shooting down, so the engine was designed
for a 15-minute service life or something like that. In homebuilts,
they vibrated like mad, and the mag would get hot and quit. The
carburetor throttle shaft would wear the thin carb barrel walls out in
no time flat and leak air. But cheap they were, light, and plentiful.
Couple pictures of one, and one of a Franklin drone engine, too:
http://www.barnstormers.com/EVENTS/0...museum-21.html

Dan

Perhaps, like teh VW, a spacer at teh bottom of the cylinder can be
used to adjust compression?

I know someone who added a third piston ring to his pistons.

He said he got 95 hp, didn't say for how long, and I don't think he
ever ran it full bore for very long.

--

FF

Many years ago a friend of mine built a racing sports car around a McCullogh
drone engine coupled to a VW transaxle with a flipped ring gear so the
engine could mount in front of the axle. We balanced the engine and ported
and relieved it. Changed to carb out for an old one barrel Pontiac carb and
it put out about 120 HP on a dyno at 12000 rpm. ( no valve float! ) The
resulting car turned a quarter mile at the drag strip between 10.2 and 10.4
seconds. Not bad at all for a two place automobile with 66 cubic inches of
engine!

Highflyer
2008 Pinckneyville Rec Aviation Flyin

The annual flyin time is coming around again! I finally got to where I
could find things in the hangar again, which is a sure indication that it is
time to start flyin preparations!

The local motels will be filling up fast again so you may want to get your
reservations in as soon as you can if you want a close motel room.

WHEN: May 16, 17, and 18 this year. Once again, it is the full weekend
prior to the Memorial Day official weekend. This has become the traditional
historical date for the flyin. It allows folks to plan well ahead to this
incredible trek. For many it becomes the cross country trip that they talk
about to everyone that will hold still long enough to listen.

WHE Pinckneyville DuQuoin Airport, Pinckneyville, Illinois. PJY is the
airport identifier. Put K in front if you have a fussy GPS. We are about
80 miles southeast of the Arch in St. Louis. There is a 4001 foot ( have to
be over 4000 feet for jets! ) north-south runway ( 18L – 36R ) with an 1800
foot grass runway parallel to the northern half.
( 18R – 36L ) . There is no taxiway. This an access taxiway perpendicular
to the runways. We do have instrument approachs again, but they are GPS
approachs only.

WHAT: The annual t here day get together of the diehards on the
rec.aviation newsgroups. Buddy rides all day and hangar flying all night.
Other entertainment as happens. Beer, soda, and good food. The PJY
barbeque is world renowned, as are the uniquely HOT Italian sausages served
on Thursday night. The Red Lady should be flying this year.

WHO: Pilots, about to be Pilots, wannabe Pilots, and anybody else who is
willing to put up with a bunch of wild eyed folks who talk about airplanes
and flying all day and all night.

COST: This is not one of those "break the bank" flyins. Highflyer and Mary
try to keep the costs in line so that we can have a good time without being
rich. We do that because a lot of people who come to the flyin own
airplanes. We all know that people who own an airplane are not rich
anymore! We try to collect $25 from everyone to defray the cost of the
beverages and the groceries. We do breakfast, lunch, and dinner every day.
Usually we have baby back ribs, steak, and chicken on Saturday night.
Friday night we have something good. No one goes hungry. We do have
something for vegetarians.

ACCOMODATIONS: Pitch a tent next to your airplane if you like. There is no
charge for camping on the field. We have a couple of bathrooms, but no
showers. Generally, if someone really would like to shower one of the folks
in a motel can help you out. We do have a garden hose. There are places
you can park a camper or motorhome near the action. If you are really nice,
we can even run you out an extension cord for an electrical hookup. No
sewer hookups though.

If you want a motel there are several in the area now. The preferred flyin
motel is the Mainstreet Inn, in Pinckneyville. The lady who runs it always
puts up with our group graciously. One year she even shortsheeted every bed
in the place, for a small bribe!
Her phone number is 618-357-2128. The rates are quite reasonable.

A little fancier is the local Oxbow Bed and Breakfast. This is between the
airport and town, right on the edge of town. A number of our folks stay
there every year they come and speak very highly of the establishment.
Their phone number is 618-357-9839.

We always manage to arrange some kind of transportation to and from both of
these places. If they are full there are other motels in the area and
transportation can usually be managed with no particular problems.

HOW: Flying to PJY is the primo way to arrive. If that doesn't work many
fly commercial to St. Louis and rent a car for the last 90 miles from the
airport. Whatever works for you works for us! Pinckneyville airport is
right on Illinois 127 just six miles south of the town of Pinckneyville.
Route 127 is exit 50 off of I-64. The airport is about 30 miles south of
I-64.

Please send an email to Mary at so that she can get some
idea how many steaks to buy for Saturday night dinner! It makes it a lot
easier when we have some idea of how many people to plan for meals.

in the usual VW car engine the harmonic charactersitics of the
crankshaft are such that the destructive vibration occurs a few
thousand revs above the max possible rpm so the engine never
experiences a problem.

in aircraft installations with large heavy propellors attached to the
shaft the harmonic range occurs at a lower RPM.

particularly with large 3 bladed ground adjustable composite props the
destructive harmonic range comes down to about 3,200rpm. most VW's
would run at around those revs so the problem becomes an unavoidable
one.

the destructive harmonics are indetectable in the cockpit above the
normal engine vibrations but in the engine's interior those harmonics
deliver hammer like blows to the crank web. the hollow area above the
centre of the internal web gets a fair shaking and develops a fine
hairline fatigue crack. this crack leaks copious amounts of oil and of
course there is no way of welding oily electron so the case becomes
junk.

It certainly should be possible to degrease the case by vapor
condensation. Tricloroethane was the solvent of choice before the
enviro-nazis got hold of things.


the problem can be avoided completely by using lightweight fixed two
bladed wooden props.

Better idea is to put a flywheel on the engine and use a redrive that
provides some isolation to the engine from its load. The marine
industry figured this out in the 1950s and the inboard/outdrive is
nearly universal now.

The maximum SUSTAINABLE power available from ANY air-cooled engine is
determined by the engine's ability to cool itself -- to couple its
waste-heat to the atmosphere. And with a carburetted, spark-ignited,
gasoline-fueled engine there is a LOT of waste heat to be managed
since such engines are no more than 25% efficient when it comes to
converting the heat of combustion into torque at the crankshaft. That
means that for every horsepower measured at the crank you must
generate at least four horsepower's-worth of heat in combustion.
These basic rules of thermodynamics are made even worse by two
additional factors, the first being 'Economy of Scale' in that smaller
engines are LESS thermally efficient than larger engines, and the
basic definition of Standard Day conditions -- 59.9 degrees on the
Fahrenheit scale and an atmospheric pressure of 29.92 inches of
mercury -- a fairly cool day.

With those laws of physics as preamble the next factor worthy of note
is the physical dimensions of the Volkswagen cylinder head and the
fact that ALL VW heads have the same exterior dimensions. This is
because they must fit under the stock VW engine shrouding. No
manufacturer of VW heads, either stock or after-market, offers a head
having more fin area. Indeed, most after-market heads have LESS, due
either to thickening of the combustion chamber wall or even
eliminating one of the eight fins -- and in a few cases they have done
both.

I think the Scat single unit heads have somewhat more as do the 356
Porsche heads after '59 or so. Both require different sheet metal in
the car.

All -- ALL -- Volkswagen heads in common use today are derived from
the heads developed for the 1300cc engine; their external physical
dimensions remained exactly the same for the later 1500 and 1600
engines. The output of the 1300 engine was approximately 40hp and
could SUSTAIN that level of output indefinitely under Standard Day
conditions. This engine was bored-out to 83mm to produce the 1500
engine, then over-bored to 85.5mm to create the 1600 (actual
displacement 1584cc), the maximum output of which was 57bhp for
carburetted models, achieved in the 1971 model year. But that level
of output could only be sustained for a bit less than FOUR MINUTES,
until the cylinder head temperature exceeded safe levels, again under
Standard Day conditions.

So what's this 'safe level' of CHT? About 450 degrees on the
Fahrenheit scale. This reflects the fact that VW heads are made of
CAST aluminum (as opposed to a forging) and the fact aluminum is a
'white short' metal, meaning it becomes frangible when its temperature
enters the 'plastic' range. A characteristic of white-short metals is
that when heated they fracture like a cube of sugar when subjected to
stress. The floor of the frangible range is a bit higher for a
forging -- about 550F according to Pratt-Whitney -- but can be as low
as 400F in a casting, depending upon the alloy.

You could always go to an iron or bronze (if TEL is eschewed)
head.....


A common thread used to impress technologically naive buyers is tales
of driving a Volkswagen bug or bus for hours on end with the throttle
wide open. The fact the engine was was probably producing LESS THAN
TWENTY HORSEPOWER goes unsaid. This involves the Horsepower Myth and
generally leaves a large black question mark hanging over the heads of
those without an engineering background but it needs to be touched
upon since ignorance can be as deadly as a machine gun when it comes
to aviation.

The Horsepower Myth was create by James Watt in order to sell his
modified Newcommen steam engine to mine owners. To do so he added the
element of TIME to the power equation and from that day to this the
general public has been comfortable with the idea that 'horsepower'
represents a given quanta of energy... which it does... but only
within a defined unit of TIME. And from that day to this, that
arithmetical loophole has been used by those eager to prey upon
technologically naive consumers.

Indeed, in the early days of aviation those predations cost so many
lives that government agencies had to step in, requiring the
manufacturers of aircraft engines to justify their claims of power and
durability.

------------------------------------------------------

All of which tends to leave the average homebuilder with more
questions than answers. Fortunately, the ENGINES themselves are
incapable of lying, especially when it comes to FUEL CONSUMPTION.

The Specific Fuel Consumption (SFC) of all -- ALL -- air-cooled,
gasoline-fueled, normally aspirated Otto-cycle engines is clumped near
the 0.5 mark, meaning it takes about 0.5 POUNDS of 'gasoline' (*) per
HOUR to produce ONE HORSEPOWER'S worth of torque at the crankshaft.
For aviation gasoline that works out to about 12bhp per gallon per
hour. For a 103hp engine that works out to 8.58 gph.

Liquid cooling is simply so superior that the air cooled gasoline-and
even (see Deutz) diesel-is a museum piece per se. That said the Harley
conversion seems to be working out better than anyone would have
thought.

Bill Daniels

The cooling systems on motorcycle engines do not have sufficient coolant
flow to keep the head from over heating under prolonged running at 3/4
to full output. The water craft and snowmobile engines may have better
flow but these also have access to lower temp coolant.

Honda makes a personal water craft that has a hot little 4 banger engine
that I thought might do the job. It would take some testing to see what
it's sustained power level would be.

Car engines now are designed for full throttle continuous operation
because that's how the Germans run them. Actually another application
that does that, is the common school bus. Underpowered, they are run
flat out for a long time sometimes. Most now use diesels that are way
too heavy to fly, but when they ran Chevies, they ran a regular old
four bolt forged crank SBC.

On Feb 6, 1:20 pm, cavalamb himself wrote:
RST Engineering wrote:
Come on, Bob. How do you expect the EAA to make a buck out of something as
useful as this? Sheesh, man, cherchez le dinero.

Jim

Indeed, these things are so simple -- and so fundamental to engines --
that it is difficult to understand why the EAA does NOT endorse a
program of publicly testing engines at its annual convention.

Endorsement would equate to liability.

BEsides, EAA has never really been about the reality of it - they
sell the dream.

Fantasy, even.

I didn't verify it but according to a History channel show on Tucker.
After too many failures of the Tucker engine, Franklin aircraft engines
were converted to liquid cooling and proved to be reliable and Tucker
bought the Franklin company to be sure and have an uninterrupted supply
of engines for his cars. After the bankruptcy, the Franklin engine
company was sold off but I don't know who bought it and I assumed they
were gone forever. If the Pols are doing a good job at building these
new Franklin engines, they sure look like a bargain.


Tucker didn't have a lot of common sense.

"Bret Ludwig" wrote in message
...

Car engines now are designed for full throttle continuous operation
because that's how the Germans run them. Actually another application
that does that, is the common school bus. Underpowered, they are run
flat out for a long time sometimes. Most now use diesels that are way
too heavy to fly, but when they ran Chevies, they ran a regular old
four bolt forged crank SBC.


Back in the late 70s I drove a Chevy flatbed dump truck powered by a 350.
Always hauled a 8000 lb Ditch Witch and pulled a 16000 lb Case back hoe. Had
to run flat on the floor every where I went. Never had any problems, even in
summer. Did have a nice sized radiator though.

I think of that rig every time I hear someone claim that auto engines won't
survive at high power settings.

"Bret Ludwig" wrote in message
...


I didn't verify it but according to a History channel show on Tucker.
After too many failures of the Tucker engine, Franklin aircraft engines
were converted to liquid cooling and proved to be reliable and Tucker
bought the Franklin company to be sure and have an uninterrupted supply
of engines for his cars. After the bankruptcy, the Franklin engine
company was sold off but I don't know who bought it and I assumed they
were gone forever. If the Pols are doing a good job at building these
new Franklin engines, they sure look like a bargain.


Tucker didn't have a lot of common sense.

The Franklin engine company was alive and well in the late 60's in upstate
New York. I worked with them when they were developing the new line of
Franklin Aircraft engines. These were a twin, a four cylinder and a six
cylinder engine that all used the same cylinders and valves. They brought
them out first as an engine kit for homebuilders. However that didn't go
over very well because at that time there were not all that many homebuilts
and most did not want to spend the money for a new engine. Even as a kit.
When they finally went under financially the rights to the engines were sold
to PZL in poland who continued to produce the engines until recently.

Highflyer
Highflight Aviation Services
Pinckneyville Airport, PJY
Note: rec.aviation.homebuilt annual flyin at Pinckneyville is coming up May
16,17, and 18th. See the faq at http://www.ousterhout.net/pjy-faq.html and
do let Mary know at so she knows how many groceries to lay
in.

"Highflyer" wrote:
The Franklin engine company was alive and well in the late 60's in
upstate New York. I worked with them when they were developing the
new line of Franklin Aircraft engines. These were a twin, a four
cylinder and a six cylinder engine that all used the same cylinders
and valves. They brought them out first as an engine kit for
homebuilders. However that didn't go over very well because at that
time there were not all that many homebuilts and most did not want to
spend the money for a new engine. Even as a kit. When they finally
went under financially the rights to the engines were sold to PZL in
poland who continued to produce the engines until recently.

Do you know who, if anyone, is producing them now? Also, are the guys at
this firm:

http://www.franklinengines.com/

just U.S. distributers or are they actually making them now?