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Holley carb info needed

Posted: Sun Aug 03, 2008 8:53 am
by paintertom
I have a Holley 4150 1000cfm with annular boosters, any of you guys have a book that tells what size the power valves are and what size jets it came with from the factory. You used to be able to find it all on the Holley web page but I have had no luck there...appreciate any help.
Thanks in advance,
paintertom

Posted: Sun Aug 03, 2008 9:35 am
by Bob Kraemer

Posted: Sun Aug 03, 2008 10:55 am
by paintertom
Thank you very much Bob,
That is exactly what I was looking for, found oud I am about10 sizes to big on the jet sizes and my carb has no power valves what so ever.....bought it off ebay that way.....we dropped the jet sizes to 90s but it wasn't enough, the stock jettings I found out are 84s.....
Thanks again,
Tom

Posted: Sun Aug 03, 2008 11:33 am
by Bob Kraemer
Cool, glad I could help. 8)

Posted: Mon Aug 04, 2008 1:01 pm
by Leon
It depends on the engine size and hp. Altho ive run dominators with 94 jets on both 388 and 540s.

Posted: Sat Aug 23, 2008 11:57 pm
by My427stang
Paintertom, you sure on the jet size for your specific carb?

The downleg 1000 HP series take the 84 jet combo with a .059 power valve restriction

An annular booster should see more signal at the booster head requiring less jet.

For example, an 850 BG carb (dimensionally the same as a 1000 4150) uses an 85/90 (no rear powervalve) jet combo for the downleg, but an 80/85 combo for the same carb with annular boosters. This is due to the big boosters having a better signal

Also, the HP 1000s usually run a powervalve front and back and are square jetted as delivered.

I really don't see a benefit in running the rear PV, and it can even be dangerous if it closes and leans out on the top end AND it can easily uncover during hard acceleration, just like rear jets would do without extensions EXCEPT its bigger and higher

Whichever jet combo you end up with, I recommend adding 6-8 numbers and plugging the PV in the rear (keep the front). In my 1000 HP I run 84 front (6.5 PV with .059 PVCRs) AND 90 rear, rear PV plugged

This is perfectly acceptable even for a street car, as the PV does its thing in normal driving, but when the secondaries open, all the fuel the motor needs is there