Intake Manifold Exhaust Crossover Restrictors?
#2
Burning Brakes
They block the passages that allow hot exhaust gasses to cross under the carb when the engine is cold and the exhaust heat riser valve is closed .
I would install them unless you plan to drive the car in severe cold conditions .
Bill
I would install them unless you plan to drive the car in severe cold conditions .
Bill
#3
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
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Make sure your heat riser valve on the RH exhaust manifold outlet is either gutted, removed, or wired permanently open before you install the blocking shims, or the RH exhaust gases won't have anywhere to go.
#4
Would the restrictors matter at all if they were installed or not in this situation? I'm thinking not and maybe I want to block it off completely? The shims I have just restrict the flow. They have a hole in the center to let some through. Does anyone sell block off plates or should I just make some out of sheet metal?
Last edited by maxpower_454; 06-25-2014 at 08:44 PM.
#5
Ok, so I think I figured out that the riser valve restricts the exhaust flow through the RH manifold and forces more of it through a port in the head or something that crosses over through the intake to the left hand side. I think my RH exhaust manifold has the valve removed and the hole blocked off in the plate.
Would the restrictors matter at all if they were installed or not in this situation? I'm thinking not and maybe I want to block it off completely? The shims I have just restrict the flow. They have a hole in the center to let some through. Does anyone sell block off plates or should I just make some out of sheet metal?
Would the restrictors matter at all if they were installed or not in this situation? I'm thinking not and maybe I want to block it off completely? The shims I have just restrict the flow. They have a hole in the center to let some through. Does anyone sell block off plates or should I just make some out of sheet metal?
#6
Drifting
Percolation
Ok, so I think I figured out that the riser valve restricts the exhaust flow through the RH manifold and forces more of it through a port in the head or something that crosses over through the intake to the left hand side. I think my RH exhaust manifold has the valve removed and the hole blocked off in the plate.
Would the restrictors matter at all if they were installed or not in this situation? I'm thinking not and maybe I want to block it off completely? The shims I have just restrict the flow. They have a hole in the center to let some through. Does anyone sell block off plates or should I just make some out of sheet metal?
Would the restrictors matter at all if they were installed or not in this situation? I'm thinking not and maybe I want to block it off completely? The shims I have just restrict the flow. They have a hole in the center to let some through. Does anyone sell block off plates or should I just make some out of sheet metal?
The reason to block them off is to prevent carburetor percolation due to heat from the exhaust cross over under the carb that can cause Percolation / driveability problems during extended idling or slow operation - or hard starting.
I installed restricted/blocked off manifold gaskets and removed the riser for these reasons and have had none of the issues since.
Felpro gasket is 1204
Phil