VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 auto engine conversions for airplanes use

Hi everybody
I'm designing an airplane. Aero engines being so expensive, I plan to convert an auto engine, preferably a Chevy, simply because I just like 'em. A posibility is to use a straight 6 Chev.
It is important to keep the HP to weight ratio as high as possible. My project requires about 120 HP at say 3.000 rp more or less. Therefore what I need first of all are power and torque curves, as well as power output and weight data of some 6 of the late thirties and of 1950 thereabouts. By the way, the Corvair is out of the question since very few of them reached this country.
Would you please instruct me on how to find the
required data? I've tried Chevrolet web page but the mail form is usable in the States only, and I live in Argentina, South America.
Thanks in advance,
Doug

Forget it , the chevy 6 you ask about in this forum is 85 HP and 535lbs , and if you run it at a constant 3000 rpm , kiss it good bye.
In fact , unless you have a reduction gear hub , kiss yer prop good bye at those rpms also .

There surely has to be something in Argentina that has an alloy block.

Good Luck.

How about using a VW engine? I know they are no where near the HP you specify but it seems to me I have read several articles in the past where VW engines have been modified for airplane use.

How about a Corvair engine? Should be light enough and still get the HP especially if you used a super-charger.

I would consider the later -1963 and up- 7 main bearing 6...Its lighter in weight than a 216/235,more modern, should be easier to find parts for it and available in 194,230,250 and 292 cubic inches.Not sure if and when it was available in Argentina.

Other than that a later 235 6 with full pressure oiling, etc. should do the job.According to Chevrolet figures a 125 HP 1954 Power Glide engine developed about 108 NET horse power at 3000 RPM - which would be a safe RPM range for that engine.

Forget the inline six engine, way to heavy and you would need around 2300 RPM to cruise with an about 26 - 2700 RPM for takeoff. With the weight of the 6 cylinder you would need a ton of weight in the tail of the airplane, so you cancel out everything as it wouldn't get off the ground. A Pietenpol is a very light airplane of wood & fabric. A VW opposed engine would be a good candidate or something of that nature. A later Suburu or any number of the small engines built now would work. Join EAA (Experimental Aviation Association) and learn evrything you need to know.

Hi Beamer,
You are doubly right: There are lots of VW conversions around the world, most of them in the States I guess, and their output is rather low for my purposes. Of course I can design a twin and use a couple of VW, and in fact I’ve just started to design a Twin, but using Citroen GSA engines of 65 HP each which are of a more modern design.
Many thanks for answering
Doug


Hi Dusty, Thanks for answering. I see I had the wrong idea about car engine power in those years.
Anyway, why do you say running a 1940 engine at a constant 3000 rpm will destroy it?
As regards the prop being also destroyed at the same axial speed, it is my humble opinion that there is a mistake in your point; The integrity of a prop, or fan, depends …among other things- on the tip tangential speed, which in turn depends on axial speed and diameter of prop. If my maths are not wrong, as long as you keep t.s. well below sound speed (around 1093 ft/sec) … let’s say 800 ft/sec, it is OK. With a diameter of 66 inches and at 3000 rpm the tip tang speed is an acceptable 864 ft/sec.
As for having alloy blocks in Argentina, I think you've never been here...
Thanks again
Doug


Hi 35,
The Corvair was my first bet but so far I’ve only heard of just one here in Argentina... and i’ts been bought by a friend also designing his plane!
As I stated in my first mail, very few Corvairs reached this country.
Thanks for you suggestion anyway.
Doug


Hi Chev Nut
Thank you very much for your suggestions. Before I start searching for a 1963 or up engine I must know its weight …may be you can suggest where to look?
Regards,
Doug

Didn't the '63 Buick Skylark use an aluminum V8?

Hi Gator,
If you are right I'd like some data on the '63 Buick, like weight and power and torque curves.
Thanks for you help,
Doug


Hi Walt,
The cruising and t.o. prop rpm you mention are the usual figures for planes equipped with ”˜standard’ aero engines, like Continental and Lycoming, using the more or lesss standard 6’ prop; being a pilot myself I’m aware of this figures. Granted, a 6’ prop is more efficient than a smaller one, but it doesn’t mean one can’t fit a …say- 66” prop to an engine turning at 3000 rpm or a 64” at 3200 rpm and still have some decent flights.
As for the ”˜ton at the tail’, it isn’t necessarily so. Many WW-I birds used engines which were not very different from auto engines of their time; I’d bet their weight and power output were not much better than those of a 1940 -6 cyl chevy. Of course those planes had a short …if not blunt- noses, but it made them simply more maneuvrable.

I´m sure you know the original Aircamper used a **** ”˜A’ engine, with water and radiator on top of it, quite a heavy lot giving a mere 40 HP (I think a 1928 Chevy a better choice, but the A was a simpler engine). Notwithstanding the reports tells it flew well with 2 on board. Funny, it looks like a WW-I reconaissance bird.

But on the whole you are right, a VW is OK and there is a lot of literature about the conversion (I have some). In fact I know of several Aircampers fitted with VWs … but they have looong noses to compensate for a much lighter powerhouse and due to high rpm the need a reduction unit. If a 6 were definitely out of the question my choice would be a Citroen GSA of 1300cc giving 65 HP; In fact I’m just about to buy a pair of GSA, which I plan to use in another project, a two place hidro. The bad side is that like all relatively modern engines, their higher output comes at around 5000 … 5500 rpm and they require a reduction device, something I tried to avoid using an engine whose max output occurs a little over 3000 rpm. I’m still intertested in getting old 6 cyl engines power and torque curves.

With regard your suggestion of joining the EAA, it would be a good idea if I lived in the U.S.A. This is a different world, there is a local chapter down here but I don’t think much of it; nevertheless I’ve got some manuals from them.

Best regards,
Doug

I thought it was 62. But this site indicates it was 1961. I defer, without protest.

Buick 215 aluminum V-8 info

Bill.

A version of the alloy V8 first used in the 1961-63 Buick specials was also used in much later model Land Rovers and has been used in many MGB V8 conversions.

Many thanks to 42Bill(wikipedia data downloaded ok) and to wdoftexas -not many L.R. nor MGs down here anyway...
Doug

You have generated a lot of interesting ideas. If you want the old-timey look and sound of an inline engine with light weight, would a 153" Chevy II 4cyl engine, circa 1963, work? Mercury made a 180" version for inboard boat use also. They still make performance parts for these. Many were used in midget racers before vw's came along. For 6cyl power-to-weight ratio after 1962, the 230" is probably best. The 194" is just as heavy with less power, and the 292" is a lot bigger and heavier, offsetting hp gain.

Doug - If you are determined to pursue a pre-war 6cyl car engine, you should investigate the Hudson 308" flathead six. It was notoriously fast for its size. It had a very long stroke and developed its power at low rpm. As a matter of fact, it sounded like an airplane when going around a stock car track with a bunch of V8's!

Hi fw190!
By the way is that Focke Wulf 190?
Have you looked at SAAB engines?
A 9-5 aluminum 4 cyl. non Aero engine will get you around 170 to 180hp and the Aero version will get you around 250hp (depending on what year). These engines are turbocharged and the torque curves come on strong at lower rpm's. I don't know what the end application is, but I think this would be a hot set up if your airframe can handle the speed. Weight wise this engines will be much less than the Chevy engines, and therefore wing loading will be more favorable. Pound/HP is the big advantage.