Little known what ifs

[Shortround6]

Some historic "what ifs" or "almosts" help show that sometimes it wasn't want of trying or creative thinking.

Harry Miller of Offenhauser engine fame (he was the primary designer) was involved in several aircraft projects in the lead up or early part of the war. One involved Preston Tucker and the XP-57

However the engine was a straight eight? 510 cu in for 720hp?

Harry Miller may have designed a very good four cylinder race car engine but most everything after that was a derivative. Either Straight eights (2 fours put together) or V-16s. Miller had been helped in the race car engine business by two other men. Leo Goossen was the principle draftsman and actual engineer who turned Miller's ideas into working engines (what size bolts needed to keep everything together and all the other little details). Fred Offenhauser was the man who figured out how to turn the drawings into actual engines and sometimes suggested changes that made certain parts easier to manufacture or work on. By the late 30s this team was no more and Miller's ideas had no one to tone them down.
A suggested V-16 engine Miller tried to sell the army (on paper only) was supposed to make 2000hp at 5500rpm from a 1200 cubic in engine that weighed between 1000 and 1250 lbs.
The army said no thanks. Perhaps because Miller specified only 5 main bearings?

Trying to base aircraft engines on race car engines might not have been a good idea. especially considering the number of DNFs Miller/Offenhauser engines racked up during the 30s.

 

[GrauGeist]

The Miller L-510-1 engine was a 720hp V-12.

 

[Shortround6]

There seems to be quite a bit of confusion over the L-510. A V-8 I might believe. A V 12 is harder to believe because when the whole project went kaput Miller wound up with some of engine parts (in lieu of salary/pay), according to one story. After he died one half of an L-510 ( 4 cylinder block and head) was installed in a restoration of a Gulf-MIller race car as the closest engine they could get.
Please note that 510 is exactly double 255 which was a common size for Miller/Offenhauser engines although Miller did come up with a large array of different sized engines.
The Gulf-Miller car used a 255 cu in engine with the same bore and stroke as the older Miller/Offenhauser engines but used a two valve head instead of four valves and used a different form of construction, a split crankcase. Two (?) of the front engine 4 cylinder Gulf-Millers were built.

There were also 6 cylinder Gulf Miller cars. at least three and they were rear engined. They were built for a 3 liter supercharged formula. so a 12 would not be 510 cu in. but who knows?

 

[cammerjeff]

Millers engine designs were actually very advanced for the era, they also designed V8 versions (the Novi's) that ran at Indy for years. Have you ever seen how you assemble a Offenhauser engine? Assembling the bottom end is very time consuming, but for the era ingenious! The basic design was competitive in the Indy and CART series thru the 1980's. Not bad for a 1920's design.

 

[fastmongrel]

Don't straight 8s have problems with crankshafts being too flexy. I can't offhand think of a successful high revving S8.

 

[Shortround6]

Define high revving

also define successful

Miller had designed a series of 8 cylinder inlines during the 1920s, starting at 183 cu in and ending up at 91 cubic in.
The 91 was supposed to top out at 8,000rpm.

Successful racing car engine only has to last a few hours.

 

[fastmongrel]

The 91 was supposed to top out at 8,000rpm.

Was the rev limiter the Conrods coming out of the crankcase

 

[Akuma]

Don't straight 8s have problems with crankshafts being too flexy. I can't offhand think of a successful high revving S8.

Straight eight problems? Check out the Mercedes Benz 300 SLR. The car series that literally won every race in which they were entered. They solved the problem of straight eight crankshaft flex by doing the flywheel power take off from the center of the shaft instead of the more traditional placement at the end. They revved very high.

 

[special ed]

The Buick eight had enough bearings to stop crank flex but the Pontiac eight did not. I would have to get out my old motor manuals to give more details.

 

[Shortround6]

You can "fix" the straight eight crankshaft flex. For cars it is not that big a problem most of the time.

However the "fix" usually means a heavier crankshaft and crankcase (or pair of cases) than a V-8 engine.

 

[GrauGeist]

Chevy fixed their vibration problem in the L-6 (straight six: 194, 230, 250) engines by adding two mains, for a total of seven.
Ford, Chrysler, AMC, et al. continued to use five.

 

[special ed]

The Nash sixes used 7 mains also. My 232 cu in could easily best a Chv 6.

 

[GrauGeist]

The Nash sixes used 7 mains also. My 232 cu in could easily best a Chv 6.

Had a 194 in my '62 Nova that was built and could take on most smallblocks - my only problem was traction (the early Chevy IIs were super light in the rear).

 

[special ed]

A friend stuffed a 327 in an early Nova and found later the frame had twisted.

 

[GrauGeist]

A friend stuffed a 327 in an early Nova and found later the frame had twisted.

The Chevy II had a unibody, unless it's a post (100 or 200 series), a 4-door or a wagon, NEVER put a hi-performance engine in a sport-coupe (400 series). You'll twist the body and get stress tears at the rear quarter window and "A pillar".
My pumped sixes used to do a number on both my '62 Sport Coupe (437 series) bodies.