Power Valve Restrictor Channel Tuning

Ivoryk3ys78 said
Good Afternoon.

I have a proform race carb and a wideband 02 sensor. I am going to dial in the jetting for lean cruise and WOT. I would like to be able to enrich the power valve circuit more and Proform and other billet metering block style carbs have screw in jets so that you can adjust how much it enriches. My understanding are that these are 6-32 air bleeds.

My problem is I can not find different size jets for it anywhere. I can find small idle air bleeds but nothing in the diameter that you would use for power valve restrictors. I can find screw in blanks that you can drill but boy that would be some awful small drilling.

Any ideas on this would be appreciated.

Thank you

Air bleeds are for getting the AFR so its flat through the top of the run. They also can effect how smoothly the main circuit initiates but that's secondary.

The power valve channel restrictors control the amount of enrichment fuel. Think of them as an additional main jet.
If your carb's metering blocks have threaded PVCRs, then BLP or Quick Fuel or Proform should have them.
Yes the alternative is to drill your own.
There are other work arounds. To my surprise I have found the PCVR on an old holley was exactly the right size. Of the two best jettings on the chassis dyno, the leaner was just past what the engine would tolerate at highway speeds. That worked out well 'cause at the track I would have chosen the richer of the two anyway.