Power Valve
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
Power Valve
When I punch my car when in motion it drops gears and putters and does some pretty funky stuff. I checked out the power valve on my holley and it was blown. I replaced it with a power valve plug and gasket from holley. They reccommended that I increase the jets to atleast 6-8. Is this really neccessary? Can I get away with my current setup now?
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
Re: Power Valve (Eric R)
Can I not just adjust the air/fuel mixture to compensate for the fuel loss? My friend said they did it on his 383 stroker and it worked without upgradiing the jets. I am very clueless when it comes to this though. Thanks for your help.
Instructor
Joined: Jan 2004
Posts: 246
Likes: 0
From: Marshalltown Iowa
Re: Power Valve (ElectronBlueC3)
Well, think of it this way. There are roughly three parts to a carb. The idle circ, power (valve) enrichment and main/booster fuel. When you take out the transition between idle and main/booster fuel you will need to do one of two things. Either run the mixture way rich to compensate as you described (not the correct way) or increase your jet size to cover the lean condition (correct way). Can I ask why you want to remove the power valve?
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
Re: Power Valve (Eric R)
Well I only have 315 miles on this motor and all the parts and it has already blown. With this carb many guys I have talked to says they blow quite often. I wanted a way to bypass it. If I was to upgrade the jets which size would you suggest?
Instructor
Joined: Jan 2004
Posts: 246
Likes: 0
From: Marshalltown Iowa
Re: Power Valve (ElectronBlueC3)
Go to /http://www.summitracing.com and search for part number HLY-125-500 This should take care of all your power valve problems.
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
Re: Power Valve (ElectronBlueC3)
Are Holley Jet 70's big enough or what size should i go with? I only need two though correct? I'm totally ignorant when it comes to carbs. Sorry guys. Thanks again.
PS: Which one of these will be the best?? http://www.holleypartsforsale.com/jets.php
[Modified by ElectronBlueC3, 12:24 AM 2/11/2004]
PS: Which one of these will be the best?? http://www.holleypartsforsale.com/jets.php
[Modified by ElectronBlueC3, 12:24 AM 2/11/2004]
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Race Director
Joined: Oct 2000
Posts: 15,013
Likes: 79
From: central FL, near the beach.
Re: Power Valve (ElectronBlueC3)
did the carb have 2 PV's? which one blew? if it had only 1, BUY A NEW ONE! you may burn a piston otherwise.
or if you don't like carbs, convert to EFI.
[Modified by Matt Gruber, 7:11 AM 2/11/2004]
or if you don't like carbs, convert to EFI.
[Modified by Matt Gruber, 7:11 AM 2/11/2004]
Burning Brakes
Joined: Apr 2000
Posts: 1,076
Likes: 0
From: Dixie TN
Re: Power Valve (ElectronBlueC3)
I thought i saw a kit in summit that had a drill bit and a small screw that was supposed to stop the power valve from blowing. If anyone has done this already tell us if it worked. Thanks in advance. :conehead :confused:
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Re: Power Valve (A78Corvette)
The blowout kit does work. A 25 pound monkey could install it on a lunch break. But if the engine is running fairly well, it would be pretty unusual to blow a valve. They're so easy to change anyway. Running without a power valve is really a track modification.
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Re: Power Valve (ElectronBlueC3)
... I am very clueless when it comes to this though. Thanks for your help.
Or learn all about carbs then you will do A above.
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Power Valve (ElectronBlueC3)
Is this the carb you have:
http://holley.com/HiOctn/ProdLine/Pr...C/0-4777C.html
If so it already should have power valve blow out protection:
Features
Model 4150
Unique shiny / chromate dip finish
Double pump
Mechanical secondaries
Center hung float bowls
Manual choke
Power valve blow-out protection
100% wet-flow tested and calibrated
Believe all newer Holley's come with the blow out protection already installed.
http://holley.com/HiOctn/ProdLine/Pr...C/0-4777C.html
If so it already should have power valve blow out protection:
Features
Model 4150
Unique shiny / chromate dip finish
Double pump
Mechanical secondaries
Center hung float bowls
Manual choke
Power valve blow-out protection
100% wet-flow tested and calibrated
Believe all newer Holley's come with the blow out protection already installed.
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
Re: Power Valve (Fevre)
This is the one I have with power valve blowout protection and still managed to bust way before only 300 miles...
http://www.holley.com/HiOctn/ProdLin.../0-80457S.html
http://www.holley.com/HiOctn/ProdLin.../0-80457S.html
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Power Valve (ElectronBlueC3)
I feel any street car needs a power valve for good gas mileage and less wear on the engine, alot less wear.
I chose a power valve just a few steps below normal cruising vacuum. I want the power valve to open passing cars, going up slight hills etc etc. I run the engine lean for clean running, good mileage and less wear but use the power valve to to richen it up any time the throttle is pushed even slightly.
This is what the power valve was designed for. Lean cruising and an extra enriching circuit.
Power valves are not easy to blow and any newer car has the check valve built in years ago.
Don't run without a power valve.
I chose a power valve just a few steps below normal cruising vacuum. I want the power valve to open passing cars, going up slight hills etc etc. I run the engine lean for clean running, good mileage and less wear but use the power valve to to richen it up any time the throttle is pushed even slightly.
This is what the power valve was designed for. Lean cruising and an extra enriching circuit.
Power valves are not easy to blow and any newer car has the check valve built in years ago.
Don't run without a power valve.
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Power Valve (norvalwilhelm)
I feel any street car needs a power valve for good gas mileage and less wear on the engine, alot less wear.
I chose a power valve just a few steps below normal cruising vacuum. I want the power valve to open passing cars, going up slight hills etc etc. I run the engine lean for clean running, good mileage and less wear but use the power valve to to richen it up any time the throttle is pushed even slightly.
This is what the power valve was designed for. Lean cruising and an extra enriching circuit.
Power valves are not easy to blow and any newer car has the check valve built in years ago.
Don't run without a power valve.
I chose a power valve just a few steps below normal cruising vacuum. I want the power valve to open passing cars, going up slight hills etc etc. I run the engine lean for clean running, good mileage and less wear but use the power valve to to richen it up any time the throttle is pushed even slightly.
This is what the power valve was designed for. Lean cruising and an extra enriching circuit.
Power valves are not easy to blow and any newer car has the check valve built in years ago.
Don't run without a power valve.
Do you run all the same powervalves or do you have them stepped? I actually have mine stepped so the eng gets some fuel underlight loads and more if it really needs it. Suppose on a unblown 350 it would only need one powervalve to feed it as opposed to your blown 468.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Power Valve (Fevre)
Do you run all the same powervalves or do you have them stepped? I actually have mine stepped so the eng gets some fuel underlight loads and more if it really needs it. Suppose on a unblown 350 it would only need one powervalve to feed it as opposed to your blown 468.
I don't know what stepped power valves are. Mine are either all on or off.
That said I don't run springs on the power valves. I remove the springs from stock power valves , remember I run a blower. I also reference my power valves to the intake manifold. If the intake is under vacuum, any vacuum the power valves are sucked closed, get into positive pressure and the vacuum goes positive and the power valves are blown off their seats and richen the fuel mixture.
Referencing to the intake involves drill new passages, closing old ones and running external lines from the intake to the carbs.
I don't know what stepped power valves are. Mine are either all on or off.
That said I don't run springs on the power valves. I remove the springs from stock power valves , remember I run a blower. I also reference my power valves to the intake manifold. If the intake is under vacuum, any vacuum the power valves are sucked closed, get into positive pressure and the vacuum goes positive and the power valves are blown off their seats and richen the fuel mixture.
Referencing to the intake involves drill new passages, closing old ones and running external lines from the intake to the carbs.