Power valve?
 

I've got a 68 Camaro stocker that currently has a 461 in it.I've always ran a primary pv in it when it had an automatic,it now has a stick,no changes to the engine.It's very choppy in 1st gear going thru the pits,clears up halfway thru the gear.Do you stick guys run power valves?

Re: Power valve?
 

Sorry,I meant to post this in tech.Will the moderator please move it? Thank you.

Re: Power valve?
 

A power valve will help but you dont want it to rupture if you ever had a backfire! I never run them have had good luck without!

Re: Power valve?
 

Just to be clear,it does have a pv in it now,same one that it had with automatic.

Re: Power valve?
 

Power valve is only affected by engine vacuum. and it must be closed at idle The # on the PV body is the inches of vacuum it will open.
Check the engine vacuum and use a PV a couple inches higher.
Think I got it right. :)

Re: Power valve?
 

Maybe around a 3.5 PV just a guess?

Re: Power valve?
 

I've been advised to do away with any PV...no more guess work.

Re: Power valve?
 

I never run them my homemade carbs get the job done!

Re: Power valve?
 

Thanks everyone. Power valve is correct for engine,even tried a new one,cleaned out carb,blew it out,float level and fuel pressure checked.This carb worked very well with a foot braked auto,crisp and did not have the problem going thru the pits in 1st gear.Problem started with stick installation,it's choppy and surges until about 2500-3000 in first then is fine.I just wondered if the stick guys pulled the valve....I'm going to order a block off plug and up the jets......Thank you.

Re: Power valve?
 

I am watching this question with interest.

*one thought, when driving at low speed only have the throttle open a small amount and regulate the car speed by selecting whatever gear gives the desired pit road speed.

*I have experimented with power valves on gas carbs. I like the low speed performance and cleaner when staging with footbrake. With trans brake leaving where you are wide open on converter or two step I do not run a power valve.

*I do know it is common with Methanol carbs to run a primary power valve.

It may mostly come down to personal preference.

I would like to know the % of who runs what.