RickB wrote:
"... since the only propulsion source of heat is the engine itself, the exhaust system is immaterial to how hot the engine room gets."
I think you'd better check for an exhaust leak on your boat.
So some questioning assumptions from someone who admits to not knowing much about this topic.
An engine generates heat when it's running because of the internal heat of combustion and that heat's distribution thorughout the engine block from being transmitted via the metal, coolant cirulation, etc.* Right, wrong?
The temperature of the exhaust at a given power*setting and load*leaving the cylinders is going to be "x" regardless of what that exhaust gets fed into.* Right, wrong?
The exhaust manifold is going to radiate heat into the engine room.* Right, wrong?
If the exhaust manifold is water cooled, it will radiate less heat into the engine room than a similar but uncooled manifold.* Right, wrong?
If you have a non-water-cooled exhaust manifold and a non-water-cooled muffler and exhaust pipe, those components will radiate heat more heat into the engine room than the same components that are water-cooled.* Right, wrong?
The variable in the previous statement is the insulation on the dry*exhaust manifold, muffler, and exhaust hose/pipe runs.* Right, wrong?
If my assumptions are correct, logic would dictate there are two heat sources in the engine room, not just one.* The engine itself-- a big block of hot metal--- and the exhaust components.* So the type and construction of the exhaust system would seem to have a major effect on heat being radiated from the components.
All of which would lead me to believe that the exhaust system has a definite influence on the amount of*heat in the engine room.
*
-- Edited by Marin on Monday 3rd of May 2010 02:59:32 PM