power valve question

[billfish]

I have a stock 1951 8BA

I would like to install a power (valve block off plug) in my 94 holly carburetor to determine once and for all if this is the source of my leak down problem.

What can I expect as far as performance with no power valve?

Attached is a picture of the plug I will be trying to use.

 

[tubman]

I don't think this is the best way to go about this. It may be the gasket or seat that is leaking, and you will get a false positive. What I do when I suspect a leaking power valve is to remove the carburetor and place it in a pie pan in a suitable piece of wood (to make up for the fact that the throttle lever protrudes below the base of the carburetor) and fill the bowl with gas and place the top back on the carburetor and let it sit that way over night. You will be able to tell the next day if you have a leaky power valve.

 

[billfish]

Tubman
Thanks for your reply- I have the carb on the bench now with gas in the bowl.

I am still curious as to how the engine would perform without the power valve. I have read on this site that the car would run but with a lack of punch when you hit the gas.

thanks and whats your opinion on this question?

Bill

 

[scicala]

The engine would still run OK with the power valve blocked until you put it under a load and get the manifold vacuum below about 7 or 8 inches of vacuum, then the engine would run leaner than required for good performance. Still driveable, but not optimum performance.


Sal

 

[billfish]

Thanks tubman ad scicala

The fuel bowl lost about 1/4 inch over night--The only wetness i see is at one of the two fuel jet access plugs located on the fuel bowl. I replaced these gaskets and will check tomorrow.

Bill