exhaust steam

[tfret]

1984 MCM260, through hull exhaust. Raw water cooling. Never run in salt water, fresh water only. I get a fair amount of steam from the exhaust regardless of engine speed or load. The boat runs great, and I'm not "looking" for trouble, but I've read that exhaust failure is a leading cause of engine failure(?). So, I'm just trying to be precautious and see if this could be a pre-cursor to something needing attention. The engine has a new 180* T-stat, and new gauges. The gauge reads 180 at idle and 170 while under way. No indication of over heating at all. Do I need to be checking something or is this normal??

 

[John_S]

Re: exhaust steam

Check your service manual, but 180 sounds high. I think most are 160, but older ones were 140. But, I have seldomed looked at the pre-87 sbc specs.

Are you getting the same amount of steam out of both sides?

When was the last time the risers/exhaust manifolds were checked and gaskets replaced?

 

[tfret]

Re: exhaust steam

The original T-stat was 160. Had the same steam present then too. I think 160 is mainly for salt water applications to reduce salt precepitating out of the water into the engine. 180 is supposed to allow the engine to run more efficiently and is ok for fresh water. I don't know when, if ever, the risers have been removed / checked, but I've read that in fresh water applications they last a very long time.