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-   -   carb issue (https://www.racingjunk.com/forums/showthread.php?t=19535)

zerotolerance 01-16-2008 06:28 PM

carb issue
 
well guys heres what ive got. sbc 388ci 15.5:1 compression afr210 heads ported by HVH and a HV1 intake 4150 flange ported by same company with a 975 bg gold claw carb sittin on top . cam specs are as fallows .701-.701 lift 269-276@50 112 ls installed at 112. i have a lm1 wide band but the damn thing keeps sending error codes i tryed a new o2 but with no luck i think the brain went bad. the carb comes stock with 86pri and 94 sec jets in it. now i have vp c14 in it for fuel and the damn thing is messin with my head i put 80 in the pri and 86 ins the sec idles great maybe alittle rich but cant tell right now cuz my tools broke, the primary circut is responsive as hell but if i smack the secondaries it feels flat. for squirters im runnin 37 front and back. i tried uppin the secondaries and then it gergels on its self doesint like it. as of right now im lost without going to a dyno and was hoping for alittle help. hopfully somone here has a similar combo and can fill me in on what there running. if theres any other info you need just ask thanks in advance. JUNIOR

us7race 01-16-2008 06:37 PM

The jets shouldnt effect idle at all. Only under throttle. I run 84's on all 4 sides with no powervalves. Seems to work great. I think my squirters are 31's..on a 830 Holley.

zerotolerance 01-16-2008 06:54 PM

cool let me hit you guys with this also square jetting vs stager whats the benifets. this is a race car but a street race car. i drive it alittle not to much the damn fuel is to expensive. i have no pvs in this carb as of right now. should i square it off or not never squared a carb off.

bjuice 01-16-2008 07:02 PM

just a thought...where is your timing set..and is your timing light right..i have seen something close happen like this when the timing retarded...

Brian

us7race 01-16-2008 07:06 PM

Without powervalves you need to square it off from what I understand.
When I first did it I had a out of the box 750 with 71 and 80 jets with powervalves and ran 6.90 took them out and with 80's all around ran 6.80-6.83..right off. Since then I have never ran them.. 8)

zerotolerance 01-16-2008 07:06 PM

two different lights both say 38 total. im really at a loss ive tryed just about everything i can think of and still doesnt seem right so i have to turn to the experts.

oobob 01-17-2008 02:08 PM

carb issue
 
How many turns out do you have the mixture screws?
Try 2 rounds.

How far open are your butterflies?
The transfer slot should barely be showing looking from the bottom of the carb up.
Sometimes the butterflies have too much of the transfer slot uncovered which will make it run rich at idle then go very lean when you whack the throttle because it already using part of the transfer fuel supply while idling.
87-90 jets squared with no PV's should be close on the jetting

Is timing locked @ 38 or do you have an advance in the distributor?
May try locking it, if it's not already.

Have you checked for a vacuum leak?


Good Luck, Mark

zerotolerance 01-18-2008 04:21 AM

hey mark my slots are showing about .015 the mixture screws are out 1 turn. i have 78-86 in it now and when i turn the mixture screw in the idle increases. but does not die when i turn it out to half turn it still has a lean stumble apon acceleration i go out to 1 turn and its so damn fat it loads up in about 2 minutes. im thinking the idle feed jets are to big in the blocks . i have 1/8 inch holes drilled in the throttle blades, i had the car running last night and farted around with it i just cant figure it out. i called pat at pro systems and im going to send him the carb next week ive had just about enough with it. nothin like spending 1100. bucks on a carb and it just being a pos. i should have bought a holley hp ultra but i didnt call me a dumb ass. thanks guys i appreiciate everything.


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