31 President power increase

[Aussi John 1]

Can anyone tell me other than the 9 main bearings, how Studebaker increased the horsepower from 115hp in 1929 to 122hp in 1931.

Also the 29 FEs were available with 5-1 heads, 5.5-1 and 6-1 cylinder heads, but I can't see anywhere, that the higher compression engines, were more than 115hp, which they must be.

Edited September 7, 2021 by Aussi John 1 (see edit history)

[nzcarnerd]

I guess the only way to get a comparison is to run some cars with different heads on a dyno to get a power reading.

 

I have a spare head for my Dictator which had had 80 thou taken off it and I would be curious to see what effect that has. I know of someone who has a dyno so it is a case of setting up an appointment. 

 

My thoughts are that those old side valve engines are not very efficient and of course back in the day the fuel octane was quite low. I think a comp ratio of up to 7:1 should help the engine make some power, as long as the old parts don't break. I have a a rod break and destroy a block on a Dictator engine  - it was only running at about 2200rpm at the time - so am a little wary.

[Gary_Ash]

A little change in the cam, higher compression, better carbs, and Bob’s your uncle!  The Indy cars made 200 hp with the production pistons and rods, though maybe got extra treatments. 

 

[edinmass]

Compression didn’t boost horsepower much.......because available fuel to take advantage of it was non existent at the time. Many motors were dialed back for stock use and reliability. Today, with minimum modifications you can get 30 percent more power fairly easy.........we do it on our own cars. But it’s not cheap. That said.......taking a Pierce eight and making 175 horsepower transforms the car and it’s drivability. I have seen one eight......which I shall not identify making over 225 horsepower...........but it doesn’t hold together for long. 

[Gary_Ash]

I did forget to mention that the 200 hp output of the 337 cu in President engine in the Indy cars was obtained with very special racing fuel which I think included acetone and benzene. I’ve seen the fuel formula but can’t find it just now.

 

For the stock engines, General Motors bought a 1932 Studebaker President and did extensive lab testing of its performance in April, 1932.  They measured 93 hp at 3000 rpm with the exhaust system in place and 101 hp at 3200 rpm without the muffler and tailpipe. Compression ratio was stated to be 5.14:1 in the GM testing.  I have a copy of the full report.  The published 122 hp number from Studebaker was probably gross hp without exhaust system or accessories. Production cars had small carbs to get fuel economy, not max hp.  As Ed says, gas was low octane back then, so high compression didn’t buy as much as it would now with 94-97 octane. But, flathead engines don’t normally benefit from compression ratios above 8:1, even with good fuel.

 

I will disagree with Ed about the reliability of the performance engines, as the Studebaker cars raced at Indy in 1932 and 1933 without an engine failure - and a couple of those engines are still racing today. The 366 cu in Pierce-Arrow engines had longer stroke but shared many components with the Studebaker 337 cu in engines.  

[edinmass]

Gary.......the very high performance  engines were breaking cranks and blocks from crankshaft whip.......even with 9 main bearings. The engines I am referring to are not Stude or Pierce. Pierce managed 117.5 mph for 24 hours in 1932 at Bonneville with a STOCK motor........and continued on for years advancing the speed. Stutz, Duesenberg, and a bunch of others kept blowing up......... the F and L head engines were never very efficient. The Pierce 12 engines are known for  running fire trucks pumping at 80 percent throttle for days without issue. I have never seen a Pierce or Stude toss a rod through the block unless it was an intentional attempt at destruction........ Stutz, Duesenberg, and a packard often had windows punched in the block, and some in the pans..........

Edited September 8, 2021 by edinmass (see edit history)

[Aussi John 1]

Hi Edimass

 

I don't think today with modern fuels there is an octane problem. I run my cars on 91 unleaded, but we here in Australia have access to 95 unleaded and 98 unleaded, but there is no advantage on an engine with 7-1 compression ratio.

[Aussi John 1]

Hi Gary

 

 If you raise the compression too high in a side valve, you will restrict the fuel supply, usually 7-1 is high enough, but you can go a little higher.

 

 My two Presidents are 6.5-1 and 7-1 My  Brooklands President is 7-1  has done over 30, 00 trouble free  miles since 2002. 

 

I use 91 unleaded, here in Australia also have access to 95 unleaded and 98 unleaded. so the octane rating is not a problem.

 

 Nobody has answered what the differences are between the 29-30 and the 31 engines.

 

Aussie John 1

[edinmass]

6 hours ago, Aussi John 1 said:

Hi Edimass

 

I don't think today with modern fuels there is an octane problem. I run my cars on 91 unleaded, but we here in Australia have access to 95 unleaded and 98 unleaded, but there is no advantage on an engine with 7-1 compression ratio.

 

Octane today is not a problem, in the pre 1935 era it was. We run 97 octane race fuel in all our cars.......it has a shelf life of seven years, and we never have carburetor issues. Every car we have is maintained and registered for the road. Every car is ready to drive cross country, it’s a demanding and difficult task to keep them always ready to tour......but it’s the favorite part of my job.

Edited September 8, 2021 by edinmass (see edit history)

[nvonada]

Even without a compression boost the extra octane lets you advance the timing which helps.  I am running mine a few degrees ahead of what the book says.

[nzcarnerd]

The result of a rod breakage in a completely stock Dictator six engine at 2200 rpm.  It happened in 1995 and the photo was taken in 2013 when it was pulled out of the car having sat in disgrace for a few eyars. I have no idea of the engine's history but the red paint on the inside made me suspect it may have been rebuilt at some time.  The camshaft was deposited in three pieces in the side tray and the lifters etc dropped into the pan.  The damage included the carb getting knocked off the manifold, and breaking the iron starter mount. The remains did supply some parts to put another engine together.

 

Being a much older design that the later straight eights I guess there is a greater risk of breakage.