Well, I went and dynoed my car yesterday. It was a lot of fun and I got some great information. My initial base run showed me that while I seem to have screwed together a fairly healthy motor, my selection of carbs was no good. I chose an edelbrock 750 because I have always had better luck with edelbrocks than holleys in daily driver applications. well this thing runs so dang rich that it makes more smoke than power. Base run uncorrected rear wheel hp/tq: max 241.4hp/261.9tq average 221hp/228tq average air fuel ratio during the run was 11.2 grr. So then we went on to do a few pulls on the nitrous. I have a small kit (Edelbrock performer kit) and installed the 75 horse jets. I backed total timing down to 34* and made a pull. max 295.2hp 344tq average 271.7hp 277.9tq Air fuel was off the scall rich the whole run. At this point the dyno guy say "check this out" he put the nitrous jet on th fuel side and put the fuel jet on the nitrous side and pulled another degree out of the timing. This was a pretty good idea. max 327.1hp 353.8tq average 307.9hp 292.1tq Unfortunately the air fuel never got better than 11.8, but even with that trouble, that's a gain of 85.7hp and91.9tq not bad for a 75hp shot. We tried the 100hp jets, but it went so rich that we aborted the run. By the way, if anyone has a holley 650 double pumper they would like to sell or maybe part trade for the Edelbrock 750(new before this motor fired up in feb driven rarely.)please let me know. I'll post in the parts wanted forum too.
Ray, Sounds like there's a lot of potential there. If you can give me more detailed specifics on the carb you're wanting to trade and the specs of the one you want, I'll post on my local classifieds for you. What are your terms (even trade, trade + cash? etc). Lemme know, Rick
If I had saw a post by you about using a 750 on a 302, I would have advised that it's to much carb area anyways for that size motor. If you are running it out of the box, no wonder it is rich. Got to put smaller jets in.
I agree with K. Merring, you're going to have to have one WELL build 302 to hold all a 750cfm carb can give. Try jetting down your carb and see what happens, also you might want to change squiters. Just a thought. Terry Gates AKA Bossmav
carb troubles Yep. I made two mistakes with this motor. Not enough cam (228*@.050 .512 lift) and too much carb. I'm not going to bother tuning the Edelbrock. I thought about swapping jets and metering rods, but even dialed in, this carb won't allow me to realize this motors full potential. Please tell me someone has a holley 4150 laying around that your not too attatched to. I'm aiming for the old standby 650 double pump manual secondaries.
I work at a local auto parts store and was talking to a customer the other day. He had one of those really cool bikes with a 350ci on it...totally custom. Anyways, he was running a 750 edelbrock on there and was in asking about holley's. His story was that he was having similar problems, and called Edelbrocks tech line. Their suggestion was that he might want to consider switching to a brand "H" carburetor. They told him that there was a problem with the 750's (not the 650's though). If you're looking for a Holley (or a Demon, which i use and worship), my suggestion would be ebay!
