470 180 Mercruiser Exhust Manifolds

[ctriverhouse]

I'm looking at a 1987 27 Caver Santego. The owner has passed. I have no history on manifold or risers. I can get boat cheap. There are no aftermarket manifolds for this motor. Mercruisers are aprox. $3000.00 for parts. My question is how long aprox. will an aluminum manifold last in the N.E salt water? 470 is FWC. I'm aware of the 3.7 issues. (Alt., Cam seals) Thanks

 

[missalot]

Re: 470 180 Mercruiser Exhust Manifolds

There are companies that charge less than Mercury/mercruiser. I purchased a set, aluminum exhaust manifold and cast iron riser - it came with thermostat and temp sensor for about $1,250 - Yes this is a 470, I have a pair of them. Inexpensive no - if you are like me and your labor is "free" - these are interesting engines IF you stay on top of the maintenance issues. BTW, mine is an 1984, and has been in salt water all its life. the exhaust manifolds do not suffer from the salt, only the exhaust riser and it is minimal.

 

[Bt Doctur]

Re: 470 180 Mercruiser Exhust Manifolds

it better have twin motors, otherwise its not a good deal.

 

[ctriverhouse]

Re: 470 180 Mercruiser Exhust Manifolds

Missalot thanks for the quick reply. Is your boat docked in the water? Do you remember what brand you have? What did the old manifolds look like? How long are your risers lasting? Twins. Boat will be docked. Thanks for your time

 

[Don S]

Re: 470 180 Mercruiser Exhust Manifolds

The manifolds are cooled with antifreeze, so not likely needing replaced. Only the risers will see salt water and have issues.

 

[ctriverhouse]

Re: 470 180 Mercruiser Exhust Manifolds

Thanks for the replys. After a little more searching I found a few aftermarket manifolds. Got a OEM price of $835.00 with free shipping
cheaper the some of the aftermarkets. Thanks again, awesome site.

 

[stonyloam]

Re: 470 180 Mercruiser Exhust Manifolds

As Don said, the only thing that should need replacing is the exhaust elbow, part #17 here: http://www.mercruiserparts.com/Show...=EXHAUST+MANIFOLD+AND+EXHAUST+ELBOW(ALUMINUM) That is the only thing that will see salt water. The salt water exits the exchanger and flows through a hose to the fitting #24 and out. It would be wise to see if you really need a new manifold before you spend the money. Good luck.

 

[ctriverhouse]

Re: 470 180 Mercruiser Exhust Manifolds

Went to get motor running for test, pulled plugs and turned over a few times to prime oil system. Two Years on land. Coolant splashed
out #4. Pulled the riser looked fine. But the manifold was trashed. Motor#2 manifold was fine. When cranking with plugs out it makes a lot more noise then the other motor. Not sure if its a tight wrist pin or worse. Any of you folks ever been through this? If so what was the outcome? Compression just within spec wet.(WD). Any advice? Thanks All.

 

[Bondo]

Re: 470 180 Mercruiser Exhust Manifolds

Compression just within spec wet.

Ayuh,.... Find another Deal, the price just tripled on that 1....