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The majority of car owners who have either a built or stock motor, seem to use a 600 CFM carb. Since chevy engines run from 265-504 and larger, Fords from 239-427 and larger and mopars from 273-426 and larger, I am curious what other CLH members use in relation to the engine size. For example, I have a 305 chevy engine bored .060 over to 315 CI, and I use a 600 CFM carb.:) :) :)
I have a 406 sbc and use an 870.
I have a .040 over 350 and use a 600 Edelbrock.
350s @600 cfm.
depends on its application, the .030 over 305 I had in my 86 Elky ran to 6000 RPMs, I ran a 570 Holley street avenger on it.
my current 454 in my 75 stepside has a 770 Holley, probably more than I need since this motor never goes past 5000 RPMs. could easily get by with 700 CFM. John
On my 305 I went from a qudarajet 750 to a Road Demon 525 and it is probably the best carb I have ever ran on a v-8 great response. Only thing that I have run better was a 2.3liter Ford 4 /30 over with dual 40mm webers in a Dino kit car.
403 olds W350 heads. 750CFM Rochester rebuilt. However, im tempted to go edelbrock 700. Theres got to be more power in there.
Edlebrock, not unless you get the new 800 EPS, I like Holley Double Pumpers myself, with Tech's 2 times the cubic inch, you should have 800 CFM ( 806 actully ).Quote:
Originally posted by drg84
403 olds W350 heads. 750CFM Rochester rebuilt. However, im tempted to go edelbrock 700. Theres got to be more power in there.
I appreciate the concern matt, but the truth of the matter is this motor rarely sees 6000rpms, so 800cfm would be overkill. Anyway, im not big on holleys. This is a daily driver after all, and holleys dont have a great record for easy starting.
Cool, I understand your perdiciment. I don't think the edle performer remanufactures are a good buy, it seems to me that, performers wear out after a while and people would just trade in there junk carb for credit or a free new one, it's not that much more money for a brand new one than the reman, I diddn't know if you would consider buying a reman carb but, my suggestion is dont. Hope you get more performance out of a new carb, if you decide to get a new carb.Quote:
Originally posted by drg84
I appreciate the concern matt, but the truth of the matter is this motor rarely sees 6000rpms, so 800cfm would be overkill. Anyway, im not big on holleys. This is a daily driver after all, and holleys dont have a great record for easy starting.
Will be runnin about 1800-2000cfm on the 540 but thats with a blower so its hard to over cfm it...
But on the 390fe in the 66 bird i put a 600cfm holley on it and for the street it runs great.
My last gto a 72 455 had a 750cfm on that.....ran strong.
I'm runnning a Q-jet , not sure of the cfm, but the thing sucks, My 355 has got to have more power than what that thing will do, I get to like 4000 and it stops pulling, so i'm at a loss. don't know what to do with it. In a perfect world I could try a holley or something and see if it works first.....
it could be a problem with the carb, or maybe not enough fuel pressure or volume, could be in the total timing. could be alot of things. Q-jets are awesome if tuned properly, the 402 in my 73 camaro ran by far the best with a nicely tuned Q-jet, much better than when I had a 750Holley & Edelbrock on it.
About the total timing, how do you check that with a timing light??? if that is possible to do it that way. 32-36° is what I hear people say you want, but I don't know how to check it........
I would have to agree with stepside on the Q-jets. They were great carbs.
Actually, you can still buy them. Depending on the company, you can get them better than new. Of course, thats the standard on GM products.:3dSMILE:
Have 2 Chevy 350s. Both are basiclly the same, head and cam wise. Both have Edelbrocks (Carter) , one is a 600 and the other a 500. You can really tell the difference performance wise.
My 350 SBC is set to a total of 36° and I think that’s probably good for most SBC’s. First, you'll have to mark 36° on your harmonic balancer. An easy way to do this is to measure the circumference of your balancer and divide the measurement by 10 (360° ÷ 10 = 36°). Measure that calculated distance clockwise from the 0° mark and make a 36° timing mark on the harmonic balancer. If you want a different setting, just do the math.Quote:
Originally posted by Monte Man
About the total timing, how do you check that with a timing light??? if that is possible to do it that way. 32-36° is what I hear people say you want, but I don't know how to check it........
Disconnect your vacuum advance. Connect your timing light, and run your engine up to about 3,000 RPM (for only a moment while you check the timing). Loosen and rotate the “dizzy” to make any adjustments you need.
Timing 101.
Dan J
DRG I dont by into the CIX2 theory either, if that were the case my near stock 454 would need over 900 CFM. John
My panel truck 331 SB 650 Holley ran very strong. Went to big block with 750 Holley with mechanical secondaries. 389 GTO 650 Holley. Actually if I remeber right I took the carb. off the GTO when I sold it and used it on the 331 chevy. I always had good luck with the Holley. easy to tune. Little cold blooded maybe.