Carb power valve question

[ironhorse2]

I have my motorcarft 2150 off my 79 Pace Car and my rebuild kit has a power valve that is different than the one on my carb. The one on my carb has four openings and the one in the kit only has two. It's a single stage valve. All I see are the valves with 2two openings on EBAY and other places. Can someone tell me why I am not finding a valve with the four openings like on my carb?

[mrriggs]

The power valves with four holes are the old style "low flow", the ones with the two rectangular openings are the newer "high flow".

The power valve does not meter fuel flow, it only turns it on and off. The opening in the power valve just needs to be bigger than the power valve restrictions in the metering block.

Most carbs don't need the "high flow" power valve. Putting a "high flow" power valve in a carburetor that originally had a "low flow" power valve will have no effect on fuel flow.

However, you do not want to put a "low flow" power valve in a carburetor that requires a "high flow" power valve.

Since the "high flow" power valves are universal, it makes sense that manufacturers don't bother to make the "low flow" style anymore.

[ironhorse2]

Thanks for the reply!