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Discussion Starter · #1 ·
I had rebuilt the 318 for my 75 dart se about 7 months ago on highschool budget and the 750 was i all i had avialble to use at the time.

whats been done

comp cam lift is .484 its the mid range cam. cam card says 18 degress of timing

edelbrock performer dual plane

summit racing full length headers

now to the problem i had bought a "running " 600 and put it on and tuned it in to where it was able to stay running and not stall

symptoms

bog and surges when in gear even when idle is up from 800 to 1200 makes no difference still surges
it almost sounds like its missing. also at times reminds me of like a diesel idles
but in park it only bogs down when revved from idle very little

thanks for any help on this project
 

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My guess is that you have a very bad vacuum leak. Either the base gasket is bad, or the butterfly shaft on the carb is loose and leaking air. Are you certain that you have the vacuum rubber lines on correctly?
 

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I take it you are talking about a Holley carb.

Small blocks need larger squirters for small engines and they like it quick, secondary canister needs to be adjusted, the bog can be the secondaries coming on too fast and if misadjusted, actually opening at idle, there is a tiny screw on the underside of the baseplate to adjust its limit, linkage should allow a paper thin gap and that's about it. A spring kit for the secondaries can stop the bog on the other half.

Idle quality and ability is also a matter of the power vavle being correct. Take your vacuum, divide by 2 and add 2 to determine your power vavle number. 12 inches of vacuum would be 6 plus 2 equals an 8.,5 power valve. Too small allows vacuum to drop too much and then do idle drop and surge increases, too high runs too rich, backfiring can blow them out and make them leak and run rich.
 

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Discussion Starter · #4 ·
im sorry i forgot to put they were both edelbrock carbs. and there was a minor vacuum leak around the base plate but after i fixed the leak the problem still remains. and the lines are placed correctly. can the edelbrock be tunnedx the same way as holley as you had stated above?
 

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Different animals completely. The secondary should have a screw on the side of the butterfly on top that is turned to slow down the vacuum signal so they don't open too fast.

Start with the basics. Vacuum leaks first, there is a large port on the back of the carb, make sure it is closed or connected. Next, turn the needles in all the way gently and back them out two full turns, the jetting is correct when at idle, a vacuum gauge used to attain the highest vacuum, the needles, turned equally, will be 1.5 + or - to be the correct size. From there, the Edelbrock tuning page website itself has very excellent guidance to tune the carbs in the final stages.
 

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If you have a choke, sure you do, move the lever coming from the choke back to the secondaries so that the secondaries are locked out. That will tell you if the problem is in the back or front of the carb. Then we cango from there.
 

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Discussion Starter · #7 ·
i did the tunning as stated on the owners manual. and it made it alot better now it has minor stumble around 1500-2000 that is often times barely noticable. and agian at 4000 what could e the problem of this.
 

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Get on the website for Edelbrock, there are needle adjustments that are the problem at this point, the needles have steps on them that sound off.
 
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