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Holley Jetting

Posted By: MoparJ

Holley Jetting - 07/15/09 06:20 PM

I am running A 650 double pumper on my 383 in my Charger. The motor has stock heads, stock cam, Hooker headers, and a Edelbrock Performer 383 intake. I am running points, which are adjusted decently.

I am running 67s in the primaries and 70s at most in the secondaries. It feels a bit soft power wise, compaired to how it should feel and the motor is otherwise solid and timing is set ok.

Should I bump jetting up, to say, 70 on the primaries and 75-76 on the secondaries, or am I were I should be?
Posted By: 1_WILD_RT

Re: Holley Jetting - 07/15/09 06:30 PM

FWIW My Challenger has a 650DP on it, stock cam, manifolds, Performer RPM & I've got 64's in front.. But I opened the PVCR .002 so it runs about the same A/F ratio under power but it's leaner & cleaner in cruise mode.. Personally I left the 76's in the rear, when your in the throttle enough to bring in the secondaries you probably want fuel so why lean it out 6 jet sizes?
Posted By: MoparJ

Re: Holley Jetting - 07/15/09 06:47 PM

Quote:

FWIW My Challenger has a 650DP on it, stock cam, manifolds, Performer RPM & I've got 64's in front.. But I opened the PVCR .002 so it runs about the same A/F ratio under power but it's leaner & cleaner in cruise mode.. Personally I left the 76's in the rear, when your in the throttle enough to bring in the secondaries you probably want fuel so why lean it out 6 jet sizes?



The secondaries came with 70s from the factory. Hell, I run 70s in the primaries of my 600 single feed, with a plate in the rear on my 318 with a warm cam, so I figure a big block would most likely prefer a bit more secondary jetting.
Posted By: 1_WILD_RT

Re: Holley Jetting - 07/15/09 10:33 PM

Per Holleys website a 4777-2 (650DP) has a 67 in the primaries & a 76 in the secondaries.. Jet size isn't the whole picture, air bleed can cause a smaller jet to flow more fuel than a larger jet with a differeenr air bleed... The factory jetting on a DP tends to be rich as it is intended as a "offroad" part... By leaning the primary jets you clean up the idle & light cruise circuts but if you don't alter the PVCR the carb will be to lean under power... FWIW I'm not trying to sell anything & you can jet anyway that suits you...
Posted By: CJK440

Re: Holley Jetting - 07/16/09 12:17 AM

Unless you want to fool with the power valve channel restrictions, you want approx an 8 jet stagger from front to rear with a Holley that has only a Power valve in the primary metering block.

As was pointed out, the factory installed a 67 and 76 which is a 9 jet size difference. Keep the relationship.
Posted By: MoparJ

Re: Holley Jetting - 07/16/09 03:41 PM

Quote:

Unless you want to fool with the power valve channel restrictions, you want approx an 8 jet stagger from front to rear with a Holley that has only a Power valve in the primary metering block.

As was pointed out, the factory installed a 67 and 76 which is a 9 jet size difference. Keep the relationship.



Is this true even with a Street Avenger double pumper?
Posted By: CJK440

Re: Holley Jetting - 07/16/09 03:57 PM

Quote:

Quote:

Unless you want to fool with the power valve channel restrictions, you want approx an 8 jet stagger from front to rear with a Holley that has only a Power valve in the primary metering block.

As was pointed out, the factory installed a 67 and 76 which is a 9 jet size difference. Keep the relationship.



Is this true even with a Street Avenger double pumper?



Do they make a street avenger double pumper? I thought they were all Vac sec?? But either way I would try to maintain the factory jet stagger unless you really plan to get technical.
Posted By: CokeBottleKid

Re: Holley Jetting - 07/16/09 03:59 PM

Does it have a powervalve in the secondary side?
Posted By: Mr.Yuck

Re: Holley Jetting - 07/16/09 04:02 PM

I'd try 68-74...What squirters? and PV 6.5 would probably work. I'd also run your timing around 36-38* at 2400rpm. (no vac advance)
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