Re: Power valves
[Re: w2dak394]
#923604
02/08/11 01:19 PM
02/08/11 01:19 PM
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Joined: Aug 2003
Posts: 43,311
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,311
Bend,OR USA
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I keep them in all the carbs that they came in, they are a power enrichment devise to add additional fuel at wide open throttle. Which alows for a cleaner running engine at part throttle  get the correct vacume rating power valve and run it 
Last edited by Cab_Burge; 02/09/11 02:02 AM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Power valves
[Re: theman440]
#923605
02/08/11 01:21 PM
02/08/11 01:21 PM
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Joined: Jan 2004
Posts: 13,247
Mt. Vernon, Ohio
dartman366
I Live Here
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I Live Here
Joined: Jan 2004
Posts: 13,247
Mt. Vernon, Ohio
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I know a lot of guy's don't agree with my way of thinking but here go's,,I have run my car both ways and didn't see any difference in 1/4 mile performance, but what I did notice was the car idled and drove cleaner thru the pit's with a power valve, to me that is a plus and I will keep on running one. 
Light travels faster than the speed of sound,,,this is why some people seem bright untill you hear them speak.
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Re: Power valves
[Re: TheOtherDodge]
#923607
02/08/11 02:08 PM
02/08/11 02:08 PM
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Joined: Nov 2004
Posts: 6,890
North Alabama
Monte_Smith
master
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master
Joined: Nov 2004
Posts: 6,890
North Alabama
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Fuel is fuel, no matter how you get it........power valve, or jetting. Larger jetting,however does effect the low speed and part throttle drivability of a combination. So to make a carb cleaner at low speed, you put smaller jets in and add the extra fuel, in a high load, or WOT throttle condition, with a power valve. A power valve is a very simple device. Vacumn keeps it shut, so in a low vacumn condition, like WOT, it open and adds enrichment fuel. You taylor this delivery time, by the amount of vacumn it takes to keep it shut. If your motor has 12 inches of vacumn and you have a 10.5 power valve..you stick your foot in it just a little, the vacumn drops below 10.5, the valve opens. If that it too rich, too early, you slow that opening by putting a lower number valve in, say an 8.5. Now the motor gets a little run before the vacumn drops low enough to open the valve. Really no need not to have a power valve in any carb, be it race or street. Just another tuning tool, provided you know how it works. Even our Ultra-Dominator race carbs, come from the factory with power valves.
Monte
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Re: Power valves
[Re: Monte_Smith]
#923608
02/08/11 11:13 PM
02/08/11 11:13 PM
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Joined: Jun 2005
Posts: 6,257
gulfport, ms, west mi
rowin4
master
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master
Joined: Jun 2005
Posts: 6,257
gulfport, ms, west mi
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Quote:
Fuel is fuel, no matter how you get it........power valve, or jetting. Larger jetting,however does effect the low speed and part throttle drivability of a combination. So to make a carb cleaner at low speed, you put smaller jets in and add the extra fuel, in a high load, or WOT throttle condition, with a power valve. A power valve is a very simple device. Vacumn keeps it shut, so in a low vacumn condition, like WOT, it open and adds enrichment fuel. You taylor this delivery time, by the amount of vacumn it takes to keep it shut. If your motor has 12 inches of vacumn and you have a 10.5 power valve..you stick your foot in it just a little, the vacumn drops below 10.5, the valve opens. If that it too rich, too early, you slow that opening by putting a lower number valve in, say an 8.5. Now the motor gets a little run before the vacumn drops low enough to open the valve. Really no need not to have a power valve in any carb, be it race or street. Just another tuning tool, provided you know how it works. Even our Ultra-Dominator race carbs, come from the factory with power valves.
Monte
Now that is a simple explanation on how the power valve works and how you can keep it in and tune your carb to your needs. Thanks Monte
it's ok to butt heads, just don't do it with a butthead
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Re: Power valves
[Re: rowin4]
#923609
02/09/11 12:23 AM
02/09/11 12:23 AM
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Joined: Oct 2007
Posts: 4,213
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,213
New York
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I'll agree, and add that a similar function is performed by metering rods on Carter etc. - only add fuel when you need it.
The diffs:
Holley is more predictable since they're rated in vacuum, and a pair will work the same way. Easier to tune, you know what the results should be after a change.
AFB, AVS, Eddy etc. can be tuned closer for partial throttle with individual taper diameters vs. spring tension for more gradual enrichment (Holley is on/off), but it's a lot of work.
Boffin Emeritus
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