Salt water engine fail

[jumpjets]

I have been running a raw water cooled 5.7 merc in salt water for the last 5 years. I routinely inspect my manifolds and risers for excessive rust. I know I the risers, impeller, and thermostat area are critical rust areas, where else should I inspect for rust? When this engine eventually fails, I'd like to be able to anticipate how and where it will die.

Since I spend time out on the Atlantic, I want to replace the engine before I get marooned at sea.

 

[alldodge]

I have been running a raw water cooled 5.7 merc in salt water for the last 5 years. I routinely inspect my manifolds and risers for excessive rust. I know I the risers, impeller, and thermostat area are critical rust areas, where else should I inspect for rust? When this engine eventually fails, I'd like to be able to anticipate how and where it will die.

Since I spend time out on the Atlantic, I want to replace the engine before I get marooned at sea.

If your flushing with fresh water it will last longer. That said, the manifolds are in most cases the first to go. Most get 5 to 7 years before they go

 

[Bondo]

Ayuh,.... I hear the 5 to 7 year thing, 'n it makes sense,....

The block itself oughta last 20,.... I hear an iron intake manifold is good for 'bout half of that,....

 

[jumpjets]

Just to amplify, I perform a 5-10 minute fresh water flush before and after every trip. I run it on muffs before each outing to ensure its functioning. I run it after each outing just to flush.

The whole engine setup has 5 years of salt use. The manifolds look like the titanic ruins on the inside. I think I'll replace them with some GLM units.

Where should I get a new intake manifold at a decent price? Should I get a thermostat and housing as well? Water pump? Cylinder heads?

 

[alldodge]

Just to amplify, I perform a 5-10 minute fresh water flush before and after every trip. I run it on muffs before each outing to ensure its functioning. I run it after each outing just to flush.

The whole engine setup has 5 years of salt use. The manifolds look like the titanic ruins on the inside. I think I'll replace them with some GLM units.

Many GLM units need to have the surfaces flattened. Check them real good with a straight edge before use

Where should I get a new intake manifold at a decent price? Should I get a thermostat and housing as well? Water pump? Cylinder heads?

Cylinder heads should last as long as the block, I would use google and search for the part numbers for other items. Most the cost is all over the place

 

[dingbat]

Lived that scenario with my first boat. Gimbal bearings, manifolds, risers.....Never again. Sold it and went to outboards. Inboard diesel would be my other choice

 

[indy440]

I've seen the head bolts that are on the outside of the block under the manifolds rust right off and become impossible to turn also.

 

[rick3452]

I would go BARR rather than GLM, made in the USA But make sure you use only OEM Gaskets.....