What carburetor are people using on their 6cyl Sprint Engines that are not a Rochester? Looking for aftermarket sizes that work well. Down to the last bits on 2 yr full restoration and think the carb we bought is too small!
What size Quadrajet? I now the HOlley's are like 650, 750, etc. I think we looked in the Jegs catalog and the Quadrajet started at a 750 I believe.
It does not seem to be getting enough fuel. If you are slow into it then it slowly takes it fine and runs great but if you get on it there is like a starvation hesitation. We have changes jets and done all the adjustments to the carb. I think its a Holley 450 - little guy!
A 450cfm should be quite adequate for the 230 or 250 cid OHC engine when tuned right. We're stuck with a 390 cfm carb for our racing class (5.7l V-8s) but we still manage to get just under 500 hp out of it.
It sounds like you either have too little or too much fuel being delivered by the accelerator pump. Too little will give you a bog with possibly some lean misfiring (backfiring through the carb). If that has been happening you should replace the power valves with known good ones to see if the diaphragms ruptured.
Too much will act much the same but will have noticable black smoke on sudden accel and no backfiring through the carb.
A quick way to check for too much fuel is to disable the accelerator pump by pulling the front bowl off and letting the lever dangle when reinstall the bowl. Maybe check to see if that has already happened! That would cause the too lean condition.
