Proper Power Valve Selection

[Anonymous]

Not sure if this was mentioned before or not. I was reading through my holley instruction manual for my new 2bbl 2300 and basically the sizing of power valves is based on vacum at idle. Essentially you are suppose to take your engine's vacum and divide by 2. The answer is the power valve size you should be running. Holley also recomends downsizg your mains by 1 for every 2000 ft of altitude.

Just some info I thought I would share with the rest of you.

Later.

 

[Mustangaroo]

Sounds about right, I had to change to a 7.5 (75) power valve on my Holley 500 cfm in order to smooth out the performance, IIRC it was jetted with a number 68 sized jet. I'm also running a 7.5 power valve on my Holley 600 cfm 4V..........

 

[Anonymous]

Hey Ben, have you visited the Dyno after your 4v install? I finally got my car running again. I even drove it around the block this weekend.

It's back up on blocks though. The O-Ring on the dip stick in my tranny leaks real bad, plus the pan leaks a bit so I'm going to replace those. Plus now that my cam is broken in I hope to have the inner valve springs installed this weekend. Once that is done I will take it to the muffler shop. Then I'm going to do another vacum check and see if I need a different power valve and rejet the carb. I'm about 4500 ft above see level here.

Anyway, once all that is done I should be able to start driving it regularly and I will get it dynoed and get some official numbers on it.

Then I will start working on the frontend/brakes then the body then the rear end and then.......it goes on forever!

Later.