carb jetting
 

I just fitted a zz383 gm performance engine. The carb that I used is a holly double pumper 4150 series pn 0-82751 , 750 . What jets and power valve should I start with? I also used their single plane intake.

You are in the wrong section, this is Help for problems with the forum, like posting pics etc...

I have the same problem....383 with a Barry Grand 750 Mighty Demon. I know the engine is running rich so I will just get one of those jet kits from Summit or Jegs and start installing smaller ones until it runs right! :thumbs:

:rolleyes:

Why are you rolling your eyes at me? When the op first posted this it was in the Help section (like in help with posting pictures etc...).

Obviously a mod moved this thread to the proper section after my suggestion.:chill:

Carb jetting is usually pretty close. Make changes 2 steps(jet sizes) at a time; 1 step probably wouldn't show enough difference to evaluate. After you figure if you need to go richer or smaller, you can fine tune to 1 jet size.

:chevy

Normally out of the box most carbs are somewhat close for a moderate engine at sea level. The holley web site just like the Demon web site has the base line settings.

the ZZ383 and a single plane would probably use a 6.5 PV. single planes need an instant squirter. So set the squirters for instant action.