Morning, Gang!

I am running a 1962 Dynamic 88 394ci with a 2 barrel on my 64 Ninety Eight. The engine runs very strong now that I have replaced plugs, wires, cap, rotor, coil, rockers, etc. The next step on the project is to rebuild the Rochester 2Jet carb. The car runs well, but the float sometimes gets stuck and requires the "tap tap" on the bowl. The car has the factory Slim Jim and 3.42 gears. I'm not looking to build a racecar, but a few extra ponies would be nice.

My questions are:

1. Based on the info I have found, the 2 barrel-fed engine should be the 280hp version. What would the factory CFM be on this 2Jet? What size jets would a factory carb be using?
2. Would there be any performance advantage of increasing the jet size of this carb? I have read that a 2Jet can be bumped up to 500cfm. But, I know that too much CFM can hurt performance.
3. Would the engine, in its current factory configuration, support a 4 barrel carb/intake swap? Or would it be too much for the current cam/heads/etc?

Thanks!

 

You can't really compare CFM ratings of 2bbl and 4bbl carbs. 2bbl carbs are rated at a pressure drop of 3" of Hg. 4bbl carbs are rated at a pressure drop of 1.5" Hg. In any case, the large 2GC used on these motors was rated at about 435 CFM.

 

Hey Joe!

Thanks for the info! So, would up-sizing the jets in this carb be helpful or not-so-much? (...I have no idea what it currently has...)

 

Jetting needs to match the requirements of the engine. Simply upsizing the jets with no other changes will make the car run rich, lose power, and waste gas.

 

Gotcha...that kinda what I figured. Since the engine runs strong and idles well, I guess I will just rebuild the carb to it's current configuration. Thanks!