Heat Rise Question
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 923
Likes: 4
From: Austin Tx
Heat Rise Question
When the valve is closed (cold engine) does it completely block off the exhaust from pass side of the engine, forcing it back up through the crossover in the manifold? Is that how it works?I think mine might be stuck part ,all the way.
Burning Brakes
Joined: Apr 2003
Posts: 844
Likes: 0
From: Central KY
Goal: what it does is cause a restriction in the exhaust gas flow on the right side when the engine is cold - and the valve is closed. Because the gas will flow in direction of least resistance, it flows through the heat riser passages at a higher rate than when the engine warms up and the heat riser gets heated up and rotates the valve open.
Reality: These valves get sticky quite often and tend to stay in one position or the other if left alone. Good luck is if they stay open - at least you get proper exhaust flow. Bad side on that is you don't get the help in warming up the engine. On mine - wired the valve in the open position and forgot about it! A better solution would be to buy a spacer - had one ordered once but it was out of stock, indefinitely. I just cancelled that part of the order...
Reality: These valves get sticky quite often and tend to stay in one position or the other if left alone. Good luck is if they stay open - at least you get proper exhaust flow. Bad side on that is you don't get the help in warming up the engine. On mine - wired the valve in the open position and forgot about it! A better solution would be to buy a spacer - had one ordered once but it was out of stock, indefinitely. I just cancelled that part of the order...
Safety Car
Joined: Sep 1999
Posts: 4,930
Likes: 11
From: AnyTown NJ
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Originally Posted by Gage
When the valve is closed (cold engine) does it completely block off the exhaust from pass side of the engine, forcing it back up through the crossover in the manifold? Is that how it works?I think mine might be stuck part ,all the way.
With time they do rust and or corrode in place. A lot of folks either wire them open or remove it completly especially if only driving in warm temps.
