Power valve
Senior User
Joined: Mar 2002
Posts: 141
Likes: 0
From: Raleigh USA
Power valve
Where is the power valve located on my 1985 351W HO motorcraft 4bbl, and how do i remove it?
1985 Bronco XLT, 351HO 4bbl, C6, NP208 ,9" 3.55 limited slip, Warn Premium Hubs, Quad Front Shocks, Dual Flowmaster 50's, BFG 32x11.5 ATko's
1985 Bronco XLT, 351HO 4bbl, C6, NP208 ,9" 3.55 limited slip, Warn Premium Hubs, Quad Front Shocks, Dual Flowmaster 50's, BFG 32x11.5 ATko's
Laughing Gas
Joined: Jul 1999
Posts: 1,047
Likes: 22
From: Lacey, WA
Power valve
Hi,
You say that the carb is a Motorcraft. Arn't they the same as a Holley? Anyway, if it is the same as a Holley the Power valve can be found by taking off the front bowel. Looking at the carb body now you see a metering block. The power valve is screwed into the oppisite side of this block. The block should pull right off, or it may have came loose when you got the bowel off. The head of the valve is the size of a quarter. You can't miss it. Look for a number on the valve. Usually a "65". This means the valve operates at 6.5" of hg. Depending on the valve style there are 2 different types of gaskets that go under it's base.
On older carbs these valves are prone to having their diaphrams ruptured from backfires. Newer carbs have "Backfire protection" built in. There are kits available for old carbs also for this protection.
Oops, sorry for the rambling.
Lee
You say that the carb is a Motorcraft. Arn't they the same as a Holley? Anyway, if it is the same as a Holley the Power valve can be found by taking off the front bowel. Looking at the carb body now you see a metering block. The power valve is screwed into the oppisite side of this block. The block should pull right off, or it may have came loose when you got the bowel off. The head of the valve is the size of a quarter. You can't miss it. Look for a number on the valve. Usually a "65". This means the valve operates at 6.5" of hg. Depending on the valve style there are 2 different types of gaskets that go under it's base.
On older carbs these valves are prone to having their diaphrams ruptured from backfires. Newer carbs have "Backfire protection" built in. There are kits available for old carbs also for this protection.
Oops, sorry for the rambling.
Lee
