Jet Help???????

[Andrew]

I'm currently putting together a "500 stroker 10.5:1,Lunati hyd roller lift- .535/.550, duration-231/239, Eddie RPM performer heads, Probably go with TTI 2" primaries to 3" exh. I'm rebuilding the 6 pack now. I have a bucket of chem-dip and gasket rebuild kits from Holley, but I really don't know what jets to use. I don't think this engine will ever see a dyno. I have a feeling this is a pretty common build so does anyone have a suggestion what size jets I should use???

 

[Meep-Meep]

I assume you are running factory six pack carbs? The main jets on the center carb are 64's with the factory metering block. The outboards use a metering plate and those are somewhere around .090". I'd have to look at my carbs to see exactly what the plates are and maybe get a part number off them.

 

[Andrew]

Hey Meep,

Mopar 6 pack Handbook lists stock outboard carb Main restriction as .052". I called Holley, and they told me based on the numbers stamped on mine that mine is .071. Also my center carb jets are #70 instead of the factory 64's. I've heard the center carb jets should not be increased much and the outboards go into 80's or 90's but I'm not sure where my build puts me on that scale.

 

[Meep-Meep]

I know from memory the factory center carb is not 70 but the outboard carbs are big but don't remember exactly. I think .090 is out of the DC engine book. I will have to look at my carbs and measure the restrictions and get back to you. No matter what go with the recommended jetting for the carb used. Emulsion tubes and air bleeds all play a roll in determining the correct mixture at various RPM's. If you have to deviate a lot in the main jet size the carbs you have are not correct for the application. .052 sounds small for the outboard carbs, especially with no power valve, but then again it all depends on the air bleeds and emulsion tubes.