Well my babies back on the road again. FINALLY after 6 months we finished it up. A friend of mine (who's name I won't mention at his request, LOL) did a bunch of work for me. He originally had plans on working the 416 castings I had but both had horrible core shift and he broke through in a few places (though it can be very easily fixed) so he went ahead and ported and polished my 350 heads (the ones that came stock on my LM-1, 72cc). He did a real nice bowl blend and opened the ports up for me. On top of that he back cut and polished the valves and we intalled new springs, locks, and retainers (doing away with the damn rotators). Then he fabbed the new radiator on (I'll get some pics of that and the car finished), and trans cooler, and port matched the intake. Here are some pics of the heads right as he started cutting away at the intake ports.

I do have a few questions though. First off I think something wrong with either the carb or there is a serious vacuum leak. The car will load up sometimes when giving a quick stab at the throttle. When I'm driving at down the road and push the gas a little it sometimes will hesitate. I tried adjusting the idle mixture screws thinking this would help any off idle hesitation but it didn't. This only happens every once in a while. The car has around 150 psi of cylinder pressure and is pulling a steady 15 inches of vac. The carb is an edelbrock electric choke 600 cfm performer. It sat for a very long time but I'm not sure if that would have anything to do with it. Plugs look tan indicating that its running about where it needs to be AF wise. Not sure maybe someone can help me a little. I'm wanting to rebuild a holley but I'm a little poor at the moment. Sorry for the long post just trying to give the facts.

Thanks
Brian

 

here's one more.

 

sure dose look good bro glad to here she back in the driveway hope she runs in the eights now/ good luck

NO4NJUNK CAR
:hail: :hail: :hail:

ONE DAY!!!:lala:

 

It has nothing to do with the idle screws...once the throttle is cracked open just a we bit, it transitions to the primary circuit.

Edelbrock has some good info on their website to tune the Performer carbs.

Good luck...did you try the carb board yet? Assume timing is advanced enough to take care of the new engine?

 

Thanks Xcelerat,

Mike, I wasn't sure if It was purely related to the carb so I stuck it in here. I know that once the throttle is cracked it switches to the primary circuit but I thought adjusting the screws for the best vacuum would help that transition a little better. As far as the timing I'm not sure what my total should be? My initial is at 14. How much advance should I have (est.)?? Does 15 inches of vac sound about right with the size cam I have and the compression?

Thanks

 

congrats man, I'm still waiting for some warm weather to get mine back together.

 

Yeah, 15in/hg with a 224* cam, is fine, IMO. The rule of thumb for total mech+initial (w/o vacuum) is 35/36* all in by 3000, the adjust accordingly.

But it seems timing is not so much the issue here (initial is high enough), part throttle tip-in is...definitely would lead me back to tuning the carb appropriately.

Did you look at Edelbrocks site? Jegs and Summit carry everything they suggest for modding the carb.

 

I used to run an edelbrock carb on my 79 Trans Am and i had the same problem . I set up the accelerator pump to come on quicker and put different springs on the rods and that fixed it . I would recommend getting their tuning kit , its about 50 bucks , but its invaluable when you are tryin to tune their carbs . try setting the accelerator pump to come on sooner first , that might be all you need to do . Also , on some intakes , you have to buy an adapter plate that goes between the carb and intake ,and if you didnt get it like i did , you will always have hesatation problems . I had a performer intake too and thought that since i was using the performer intake and carb that i wouldnt need anything else - not so . They have a chart thats included with the carb that will let you know whether you need that adapter plate for your application . Good luck !

Joe

 

Not real sure on the eld. carb set ups, but on the rochester there is a screw to adjust the tension on the spring for the secondary butterflys, if it was set too loose they would open with very little effort and cause a stumble under light throttle acceleration.