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View Full Version : need powervalve info?!



Brendella
06-01-2002, 11:15 AM
I rebuilt my carbs and before I essemble the together I need some new power valves.
the trick kits came with 5 and 6.5 but my old ones are 9
what I want to know is for a ford 460 bored 40 over with flat tops one valve relief and is running a clay smith 290 cam with 560 lift, top off with a weiand tunnel ram with dual 750s
what size pwervalve should run?
thanks for any help in advance.
brian

lakecrazy
06-01-2002, 02:14 PM
I run a 3.5 power valve in the front metering block and no rear power valve (plugged) on an 850 dp Holley on my Ford 460 with cam specs similar to yours.

Brendella
06-01-2002, 07:11 PM
thanks lake crazy, one question more the lower the vaccum the lower the number I want.
And exactly how does the pwer valve work and what does it do?

1quickjet
06-01-2002, 07:13 PM
Brendella, check out the GearHeads page. There have been some good help regarding powervalve questions recently. Good Luck. 1QJ

jetblue
06-02-2002, 04:40 PM
You really need to install a vaccum guage on your motor, as a power valve operates off of vaccum. Unless you test your own engine, you are guessing. A powervalve opens at a certain point, or, fall of vaccum. A 6.5 opens when vaccum reaches 6.5 inches of vaccum. I'm sure there are others here who have more time to explain, but I'm doing margeritas. Chowda!!!!!!!!!!!!!!!

triple x tx
06-07-2002, 09:10 PM
take a vac. reading, whatever your reading is at idle (for example 13 lbs) divide that by two and thats the powervalve you run..........so if you have 13 lbs of vac. at idle you want to run 6.5 powervalve in primary and blockoff in secondary

hack job
06-07-2002, 09:44 PM
ok here is the info i got from goerge at clay smith i was told to run 2.5 and only on the primarys ( my carbs only have those 4779) and iam running a weiand tunnel ram and what not. my motor is being built by clay smith as we speek. so thats what iam going to run. i would imagine that you could run the same. just my .02
Tyson www.plumbersassracing.com (http://www.plumbersassracing.com)

triple x tx
06-07-2002, 09:59 PM
all motors are different...he could probably use just about any combo and it would work....but to get peak performance you need a vac gage and use the formula i stated before....that formula is straght for the holley tech line

Brendella
06-08-2002, 09:58 PM
thanks guys well understood
brian