Just put a new carb on my engine. ? is about at what rpms the power valves should open. Max rpm is 4900-5000, 6.5 power valves in the primary and secondarys, 74 jets squared, engine vaccum gets to 6.5 at 4500 rpms. Is this the correct opening point for the power valves or should they open sooner?
Just put a new carb on my engine. ? is about at what rpms the power valves should open. Max rpm is 4900-5000, 6.5 power valves in the primary and secondarys, 74 jets squared, engine vaccum gets to 6.5 at 4500 rpms. Is this the correct opening point for the power valves or should they open sooner?
is this the 750cfm dominator u were going to buy?...if so...leave it alone & run it...good to go out of the box
fastrat
Power valves open when the vacuum drops to the number on the power valve. IE: A 6.5 will open at 6.5 " of vacuum and below. Put a vacuum gauge on your intake manifold and that will tell you when it is opening. How quickly you press on the accelerator will determine when it opens.
Power valves open when the vacuum drops to the number on the power valve. IE: A 6.5 will open at 6.5 " of vacuum and below. Put a vacuum gauge on your intake manifold and that will tell you when it is opening. How quickly you press on the accelerator will determine when it opens.
Did that sunday, they open at 4500 rpms.
engine vaccum gets to 6.5 at 4500 rpms. Is this the correct opening point for the power valves or should they open sooner?
is this the 750cfm dominator u were going to buy?...if so...leave it alone & run it...good to go out of the box
fastrat
Yes it is and it runs awesome. Just can't leave well enough alone. That dam thing doesn't miss a lick, accelerates so smooth its not even funny. No missing, and much more low end power than the Demon 850 i had.
Just put a new carb on my engine. ? is about at what rpms the power valves should open. Max rpm is 4900-5000, 6.5 power valves in the primary and secondarys, 74 jets squared, engine vaccum gets to 6.5 at 4500 rpms. Is this the correct opening point for the power valves or should they open sooner?
The power valve opens based on LOAD, not RPM. Manifold vacuum is your measure of load. Go out and measure manifold vacuum at WOT and compare that to the power valve number. I suspect that 6.5 PV will be just fine.
Yes it is and it runs awesome. Just can't leave well enough alone. That dam thing doesn't miss a lick, accelerates so smooth its not even funny. No missing, and much more low end power than the Demon 850 i had.
there ya go!! lolthe old saying=="if it ain't broke--don't F--K with it"...now GOOOOO have fun!
fastrat
With the power valve in your case 6.5 when the vaccume drops below that number that is when it opens enriching the mixture.You need at least 6.5 inches of vaccume to hold it shut.It sounds like you are running fine.If you can mash the throttle without hesitation and your not leaning out or excessively rich on the top end leave it alone.
I guess a better way to ask my question is how would one know whether he needed a different power valve, one that opens with less or more vaccum? Just trying to learn here is all.
Found the answer here. Mine is perfect.
http://www.holley.com/data/TechServi...wer_valves.pdf
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