Exhaust manifold life expectancy in saltwater?

[jayc]

5.7 engine with raw water cooling run in saltwater.
I flush with fresh water after each use (usually twice a week or more during the summer) for a good 5 - 10mins.

The exhaust manifolds are now 3 years old so how how can I expect to get from them. Some say 3-4 years and others say 6-8 years.

Anyone care to comment?

 

[LeytonC]

Checkout this months MBM, there is a company that makes stainless manifolds - in gear scene i think, i dont have my copy handy at the moment - and they give them 25 year life.

 

[oldgit]

Job for winter !

Get a couple of gaskets from your dealer.Get a set of top quality spanners/sockets .(the cheap crap stuff with the thick socket wall will not go twixt nut and riser),a gallon of WD40 and if you have too a gas bottle.
Pick a nice sunny day and bring your double jointed set of elbows.
All set,good.Take em off and check the water ways are clear while the nuts will still undo without violence.
I had a mercruiser riser fail after about 2 years,not a long job just fiddly.

 

[marine]

Had a failure of a riser causing seawater contamination resulting in a thrown valve spring. Having said that the boat was 12 years old (3 with me) and to my knowledge never flushed.
If you have the time it might be worth lifting the riser covers to check, otherwise with your maintenance regime, your good for some years yet...don't quote me though!.

Steve