Risers

mthieme

Captain
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Oct 6, 2007
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Anyone ever run across or heard of cast stainless steel Mercuiser risers?
 

jerryjerry05

Supreme Mariner
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May 7, 2008
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18,195
Re: Risers

They are expensive and used in a lot of high performance motors.You can use them on a regullar motor too.Jerry
 

mthieme

Captain
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Oct 6, 2007
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Re: Risers

Thanks guys.

I didn't believe they were stainless.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Risers

I had a pair on my old V6. They'll outlast the engine, as long as you don't run them dry.

Mec ran them for a few years and then stopped making them. The story I was told was that they were replacing so many under warranty (because people were running them dry!) that it was un-economical for them. Shame really, they solve the problem of having to replace elbows every few years...

Chris...........
 

TilliamWe

Banned
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Dec 21, 2004
Messages
6,579
Re: Risers

My 1997 5.7LX EFI Gen + engine has them on it. Standard, from the factory.

Part #s 816900A 5 and 816900A 9. Mercruiser list price of $609.98/ea.
 

lmannyr

Master Chief Petty Officer
Joined
Jul 5, 2007
Messages
815
Re: Risers

Why would one run dry? Thats just asking for a water impellar change. Unless your talking about dry exhaust. BTW, what exactly happens when you run them dry?
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Risers

SS and cast iron expand and contract at different rates. During an oveheat, the gasket between the SS riser and the Cast Iron manifold fails and you get water in the cylinders when you shut the engine off.
In salt water, that is a recipt for disaster if the water sets in the cylinders for a couple of days.
 

mthieme

Captain
Joined
Oct 6, 2007
Messages
3,270
Re: Risers

Would it be normal for SS risers to have a thin film of rust around the hose connections and inside the jackets if used in brackish waters? The fittings, especially the little hose fitting are all as meaty as new though. How could one definitely tell them apart from low hour cast iron??
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: Risers

Would it be normal for SS risers to have a thin film of rust around the hose connections and inside the jackets if used in brackish waters?

Yes, some discoloring is normal. Like they always told me, it stainless, not stainproof :)

How could one definitely tell them apart from low hour cast iron??

SS is non magnetic.
 

mthieme

Captain
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Oct 6, 2007
Messages
3,270
Re: Risers

Perfect. I wasn't sure about the magnetic thing.
thanks - exactly what I needed.
 
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