huge cam, what carb?

[dusterbd13]

so the carb i was trying to save was junk, and i have to buy another one. ive always been a carter guy, and know them pretty well. but i dont know how well they do with huge cams. the combo im trying to top off is a 30 over 360 mopar, I beam rods, forged pistons, 9.5:1 compression.564/.570 lift 236/242 duration solid roller, Indy modded Eddy heads, victor single plane, four hole 1 inch spacer, stepped headers, 3 inch x-pipe exhaust. the car is primarily a street driver, with a little corners and drag racing thrown in for fun. it will wind up with a lot more chassis than it already has, i can tell that much from the brief test drive. im really considering the 800 CFM AVS that edelbrock is making now, but dont know how it will idle with that cam and intake.

any ideas? or do i have to get an exponentially more finicky and expensive holley?

Michael

[ProdigyCustoms]

I ended up with a extra Holley 750HP vacuum secondary number 0-82750 . It is one Badd Ass carb. Should be perfect for you.

It sells at the big mail orders for $519, I will take $450 for it.

[sporter]

You'll have to tune any carb and any carb can be tuned. Personally, since it's a Mopar I'd look for a 1000 cfm Thermoquad. They make a very nice street carb. The AVS is supposed to be great too. Here's a link of a quick test conducted by a carb guru between a custom Qjet, AVS and custom Holley. basically, the Qjet made the most power (highest speed), the Holley ran the lowest ET and the AVS was in the middle. All within a tenth and 1 mph. If you do get a Holley, the one above is a pretty good choice.

http://forums.performanceyears.com/f...d.php?t=533630

[DCx]

i run a 243/249 .578/.585 lunati voodoo solid roller in my small block. i have had no issues with my 750 mighty demon.

here is a video of it

http://www.youtube.com/watch?v=XGx2syDo8lM

[68sixspeed]

I'd go with a holley or holley based 750 for that combo; maybe even a 650. It's not that much cubic inch or cam. I run 262/268 at .050 lift with .699/.650 lift with a 750 on the street and 950 for all out performance. The 750 has slightly better street manners due to the smaller bores, and much better fuel mileage. Dyno #'s were 612hp vs 623hp.

My prev. 358 had the same duration roller cam but with .634/.634 lift and it made 530hp on a 750cfm HP series carb, so that is probably a closer match to your motor cid wise anyway. Interestingly, it did go almost 2mph faster at the track with the 950 carb.

(so you might want to buy Frank's carb!)

-Dan

[dusterbd13]

friend of mines dad loaned me a 750 double pumper to get it on the road. so far, so good, except for it running pig rich, which i think is why it has poor throttle response and fuel economy. also idles best with the idle mixture screws turned the whole way in, which makes me wonder if the rear metering block should have screws in the holes or not. it presently doesnt. but that carb was enough for me to get the car on the road and driving. he also said that i could have it for a steal (like a hundred bucks), so i may just purchase it if i like it after a little tuning.

Michael

[Shaker455]

You'll have to tune any carb and any carb can be tuned. Personally, since it's a Mopar I'd look for a 1000 cfm Thermoquad. They make a very nice street carb. The AVS is supposed to be great too. Here's a link of a quick test conducted by a carb guru between a custom Qjet, AVS and custom Holley. basically, the Qjet made the most power (highest speed), the Holley ran the lowest ET and the AVS was in the middle. All within a tenth and 1 mph. If you do get a Holley, the one above is a pretty good choice.

http://forums.performanceyears.com/f...d.php?t=533630

That was my custom Holley I built for Cliff Ruggles

[68sixspeed]

friend of mines dad loaned me a 750 double pumper to get it on the road. so far, so good, except for it running pig rich, which i think is why it has poor throttle response and fuel economy. also idles best with the idle mixture screws turned the whole way in, which makes me wonder if the rear metering block should have screws in the holes or not. it presently doesnt. but that carb was enough for me to get the car on the road and driving. he also said that i could have it for a steal (like a hundred bucks), so i may just purchase it if i like it after a little tuning.

Michael

Suggestion- get the p/n off the carb and check the holley carb catalog for the factory settings, they are usually pretty close on jets, maybe a few points fat on primary jet size. With that cam, 6.5 power valve should be fine (install fresh ones to be safe, blow power valves will make it bad rich at idle); I'd also make sure the throttle blades are not open so much that the transfer slot is exposed. If it is, you may need to adjust the secondaries open a bit or drill the throttle blades with 1 small hole each. (.046-.062" dia to start.) Good luck, once you find a tune, I've never had to play with them that much, maybe a bit on idle depending on weather conditions, but that's it. -Dan

PS- fuel pressure- 7-8psi max, any more and you rish pushing fuel past the needle/seat and making it real rich too.