Were is it? How hard is it to change? How diffrent does the engine run when it blown? Should i just plug it? What opening vacuum sould i be using? Its for the 600 cfm DP (4776) on a 460. AntRant
[ September 17, 2002, 10:31 AM: Message edited by: AntRant ]
POwer valves are on the metering plate, which is the plate behind the fuel bowls. They are easy to change. DRain bowls take bowls off. remove plate. Install new no stick gaskets with new power valves. IF they are blow your idle will be off a bit. If you do install the block offs your smooth idle will be harder to achieve and you will have to run up to 10 jet sizes bigger. You can but the check valve for your holley which will help prevent a blow out.
If you want to know what power valve you should be using check out this link http://www.mortec.com/carbtip1.htm If you have two power valves blocking off the rear is something you might want to look into. Ive had them blow and cause plug fouling, popping and stalling, but ive also had it cause just a rough idle on another engine, it just depends on your setup how much you'll notice it. Like jslimjeff mentioned the check valve is good blow out defense.
If the boat is a hot rod ?
Plug those d#mm power valves .
It will be so much easeir to tune with them pluged.
One thing you do need to do after plugging them is richen the main jet's up about 6 numbers, If it is the 600 I'm thinking about they come with about #66main jets go up to around #71or72jets. make a pass and read a plug the plug should"""not be crystal clean white""" should be brown orhave a touch of black in them . If not go up another1-2#
eek! I'll lay off the crack pipe eek!
a lot of times if it is blown you will get a real rich mixture. I believe the power valve should be half of what your motor vacuum is. So if you are pulling 8 pounds of vacuum then you would go with a 140 or a 145 power valve. 6 lbs would be a 130 or a 135.
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