1930s carburetor question
 

So I've noticed something with older carburetors, specifically the Zenith on our A as well as whatever fancy carb is on this supercharged Duesy.

As heard in this video when the engine is revved and the carb is closed fast the engine stutters / misses.

http://youtu.be/QOQFDxRPdWM?t=37s


Is this because the mixture leans out momentarily and if so why? What changed in more modern carbs to stop this?

Re: 1930s carburetor question
 

Automatic timing advance, power valves??
Paul in CT

Re: 1930s carburetor question
 

If you have a stock A, try opening the GAV just a little more, should help. Assuming your carb is working proper with the proper jets, no air leaks around carb to intake or intake to engine.

Re: 1930s carburetor question
 

That thing sounds like a threshing machine running! I'd like to have it though.

Re: 1930s carburetor question
 

Straight 8 DOHC 32 valve super charged 320HP right from the factory in 1932.

Sorry, I love Duesys and can say without a doubt they are my dream car that I will never have.

This is riding in a stock 260HP 1929 model, no supercharger. Huge difference from a stock model A, of course also a huge price difference.
http://youtu.be/B7XNCRC5wpk

Re: 1930s carburetor question
 

Good point, didn't think of the power valve \ accelerator pump. I *think* the Duesy has automatic timing advance though I'm not sure how good.

I'll try that next time we have it out. Thanks!

Re: 1930s carburetor question
 

"Modern" at least into the '70's engines will shudder upon rapid acceleration and rapid deceleration because of weak valve springs.

Chet

Re: 1930s carburetor question
 

Mr tube, impressive car, love them too,but i couldn't. Afford one. I dont think aoutmatic trans wasn't. Availiable until 1939-1940 . The noise might be a relief valve to let the pressure from the supercharger. Out of the manifold , to prevent intake manifold explosion. Much like todays high performance tubro/ or supercharged cars. Thanks for shareing, what a great car, said to do over 60 mph in sevond gear.

Re: 1930s carburetor question
 

Perhaps you're right, the non-supercharged version doesn't seem to do it.
That is of course assuming all of the ones I've seen are running right, and being a multi-million dollar car I'd hope they are. I've also yet to find a "modified" one anywhere.

This is a non-supercharged version revving.
http://youtu.be/yHyNTe4Kue4?t=2m1s