I'm curious about how much the clearance between carb and hood may affect engine performance. I thought about it quite some time ago, but set the idea aside since the engine/car seems to run great. I assume it's the same as it was back when this car was raced by prior owners, which gives me reason to think it's not necessarily something to worry about. Thinking about it again, after a good friends pop was asking me about it at the last race. I haven't gotten an accurate measurement, but eyeballing it, there can't be more than 2 inches clearance here. Thinking about putting a block of clay up there and closing the hood to see what it shows. Any thoughts/opinions on this?

Thanks.

My flat hood was real close. I don't have a measurement. Didn't notice any performance difference when I went to a 4" cowl.

I even think there might be consistency in having less fresh air available. It's always the same hot, dirty air.

I've always heard 3 inches of clearance, which begs the question, what if you have a air cleaner with a top, it's certainly not 3 inches from the top of the carburetor.

What does help is using an air pan to trap the air into and around the carb. That resulted in a 3, almost 4 mph gain in my car.

Bob

quote:

Originally posted by Lenny5160:
My flat hood was real close. I don't have a measurement. Didn't notice any performance difference when I went to a 4" cowl.

I even think there might be consistency in having less fresh air available. It's always the same hot, dirty air.

Agreed. I have a 4” cowl and when I blocked off the rear opening with some cardboard to try it ran the same numbers. I use an air cleaner.