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Author Topic:   Power valve reccomendations
powercar821111
Member
posted April 01, 2002 09:55 PM
What size power valves do you guys reccomend using in a holley 4412 carb. The engine has 9:1 compression, stock intake, 239, 244 duration cam. Not sure how much vacuum it will pull. Thanks for any info!


KPLugnut
Member
posted April 02, 2002 08:31 AM
A ballpark starting point I would try would be about a 4.5 PV, and around a 72 - 74 jet,
assuming no work whatsoever has been done to the carb.
Just go by the common rule of thumb for choosing a power valve first, then you can experiment a little to find your own motor's specific needs.
Of course, this info above is also assuming you're running on gas...

Hope that helps,

KPLugnut

[This message has been edited by KPLugnut (edited April 02, 2002).]

powercar821111
Member
posted April 02, 2002 11:26 AM
Actually I am running on E-85. The channel restrictions have been modified and are almost .100 diameter. I have been told to run a 10.5 with a two barrel. Thanks again!


KPLugnut
Member
posted April 02, 2002 07:28 PM
OK, sorry about that. Strike that last reply from the record. LOL!....E-85 makes for a different animal. Even tho you are modified some to use that fuel (PVCR, etc), your power valve choice and the ol' rule of thumb still applies. If you are running a 10.5 PV, I can tell you that it will almost NEVER close when you need it to. IMHO, that is too high for this application. Start with a hi-flo 6.5 (alcohol PV) and go from there. Your jetting, accelerator pump circuit and quite frankly, just the idle circuit settings will make you fastest and most responsive.

Hope that helps,

Dayton Umholtz, owner
Kinetic Performance


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