Join Date: Dec 1999
Location: Buckley AFB, CO
750 carb to big on a 302? carb guys please help!
Here is the engine i'm running....
Stock 302 bottom end with 160k miles, 9:1 compression, NEVER TOUCHED, just wire brushed clean the pistons, Anderson Ford Motorsports cam of unkown specs (has to be under .520 lift to clear the stock pistons), stock unported edelbrock performer aluminum heads 1.90/1.60 valves, 1.6 pedestal mount roller rockers, edelbrock victor jr intake (ported) and a speed demon 750cfm carb. for ignition i've got a MSD billet distributor, MSDdigital 6 box, and Jacobs ignition coil. Meizere electric water pump, electric fan, griffin radiator. Tranny is a stock T-5, pro 5.0 shifter, king cobra clutch, 3.73's out back. i've got a holley blue feeding into a 8an line from the pump to the regulator, then running 6an from the reg to the carb. BBK 1 5/8" long tube headers with a custom built 2.5" hpipe and flowmaster muffers, no tail pipes. that's basically the jist of it.
The carb and intake are overkill for the motor. They were what i had last year on my 347, but i'm thinking the carb for sure is overkill for this 302. Took it to thed dyno yesterday. With the carb still untouched from last year (being jetted for the 347) running 89octane gas and low timing, the car put down 331rwhp and 309torque. It seems like my accelerator pump is ****ed though ( i need a 50cc pump) b/c for the first couple seconds it spikes lean, and stumbles real bad on the dyno. Then it goes down but still lean to about 14:1. We didn't have any accelerator pumps on the dyno last night to swap it out with, so we ended up not really messing with any jets or anything and said F-it until we can get the accel pump figured out and come back later.
My main question is, do you think i can get this carb dialed in decently even with it being overkill? I've heard that a too big of carb will make you lean anyways, so if i'm jetting it up is it even going to help me? Or should i not even waste my time on this 750 and try to get like a 650? I was planning on swapping out the accelerator pump and going back tuesday to see if it smooths out at all. I might do it just b/c it's cheap and i'm curious, but i just wanted to get some other opinions on it. The engine definetly likes the RPMs. I made 3 runs, each time i revved it higher, and it made more RPM. on my 331 hp run, it was making peak HP and still climbing at like 6300rpm where i shut it off. I don't want to take it higher then that though b/c of the pedestal mount rocker arms ( i took it to 7k when i first had it done a week ago, and two of the rockers basically fell off, lol). let me know some of your opinions guys, i'm new to this carb stuff!