Help with new primary jet selection!

[Bad Snake II]

Hi,
My car since i rebuilt the engine has ran really really ritch well today when i went out and ran it the thing slowly died and then smoke a lot of smoke poured out of the carb . The primary jets must be 100's it was a race carb on a drag car back in the 70's. The cab is a 650cfm holley single pumper non v shaped fuel bowels and has vacume secondaries. The engine set up is a 289 edelbrock performer intake and performer cam, flat top (not dished) pistons and the heads i will change to 54cc's. CAN ANY BODY TELL ME WHAT A GOOD JET SIZE IS FOR A HEALTHY RUNNING ENGINE, I want to be able to take it to the track and do a fairly decent time. But this cant be good if at idle it smokes black, it probubly is washing the cylinder walls right. does any body know how to tune a carb out really nice.
Thanks
God Bless Our Troops

 

[bnickel]

first check the jet sizes in it currently jsut to make sure what you have. i would start around a 56-58 maybe even a 60 primary jet and work from there. also check the accelerator pump, power valve and one that a lot of people overlook is the squirters, if it truly does have an enormous primary jet then it will likely have larger squirters as well.

 

[rbohm]

what bnickel said, though i would start with something like 64's in the primaries, and something like 76's in the secondaries, and a #31 pump shooter. also make sure you are running the 30cc holley accel pump. many drag racers swap to the 50cc "reo" pump, and that will load your street engine up quite heavily.

 

[Bad Snake II]

hi guys,
Well when i put it on i replaced everything in the carb the jets were the only thing i left in and the secondaries are just a alluminum plate with holes machined in it. will this pump your talking about be replaced if you completely rebuild the carb.
thanks

 

[rbohm]

will this pump your talking about be replaced if you completely rebuild the carb.
thanks

well yes and no. the 50cc pump housing is physically larger, read thicker, than the stock 30cc housing that comes from holley. when you rebuild a carb you only replace the diaphram not the housing. the 30cc pump housing is under 1/4" thick whereas the 50cc pump housing is twice the thickness of the 30cc housing.