Why do I keep blowing power valves
Thread Starter
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Why do I keep blowing power valves
I keep blowing power valves every couple of times driving the car. I took it out last night for a quick ride and got on it a few times. While cruising back home it started to ren like it was loading up. Sure enough the power valve again. This is the 3rd one in a short while. No backfires or anyting abnormal and the car ran great. It happened on the 3rd blast of the night. Just went through 1st and 2nd at 6500 rpm and when it idled back down I could tell it was not right. Don't understand. It is a 750 Holley DP carb.
Le Mans Master
Joined: Jul 2001
Posts: 9,622
Likes: 16
From: absecon nj
Re: Why do I keep blowing power valves (Gordonm)
gordon why dont you get a power valve check ball kit to eliminate blowing from holley.It might help.I know all the newer holleys already have them i it,but not the older models.
http://store.summitracing.com/partde...-125-500&N=120 4294925239 4294925135 302417
http://store.summitracing.com/partde...-125-500&N=120 4294925239 4294925135 302417
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Why do I keep blowing power valves (patsnitrovette)
patsnitrovette is right but I still don't understand why you are blowing them even without the check valve. They are not that easy to blow.
Your carb must be old if it doesn't already have the check valve
Your carb must be old if it doesn't already have the check valve
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Why do I keep blowing power valves (Gordonm)
That should have the check valve, it might be defective. 
Is there any sharp burrs around the diaphram that might be cutting it (wild shot in the dark)?
Is there any sharp burrs around the diaphram that might be cutting it (wild shot in the dark)?
Thread Starter
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Re: Why do I keep blowing power valves (Fevre)
A little better inspection this morning and it is not a blown power valve. Thats good. I still have a little idle problem. No more time until next week. I'll dig into then.
