Technical Tap for 94' power valve threads?

I have a couple Holley 94's that need the power valve threads cleaned up. Does anybody sell that particular tap? Thanks

Art

 

I take an old power valve and grind flat spots on the treads to make a chaser.....

 

Thanks for the tip.

 

To chime in...damage is most likely going to be on the lower threads, so cut away most of that old power valve and cut across the top with a shallow hacksaw cut so you can turn it with a screwdriver. This way you can runnitin from the top and push through from good threads to the bad.

 

These carbs had plugs that were epoxied in and now the threads are just crapped up. I was wondering if there was a tap available to clean the threads out. Thanks

 

Just measure the diameter of the plug across the threads and count how many threads per inch. Then ask McMaster-Carr, Grainger, or MSC for the tap.

 

The thread size is 1/2-28 for the Holley power valves. You can find them on ebay by searching for "1/2-28 tap", seems they are a popular tap for gunsmiths. Good luck.

 

Thanks guys!

 

I think you may want to consider a bottoming tap, seems that I recall that you don't have much room in the bowl before you run into an "overhang". You also may want to search "power valves 94" to see if you will need to adjust the size if using more than one carb on your engine. The original application for this Carb was on a 221 cu in engine and used a 750 power valve. When you do your search go to PC/SR either here or over on The Barn, he has done an excellent job researching the 94, a must read !

 

Found a bottoming tap on Amazon. Thanks,

Art