Exhaust Manifold & Risers

[Boating_Al]

I have about 500 hrs on my 1994 5.7 Mercruiser and believe the exhaust manifolds have never been changed, I think the risers have been….So it’s time before they start to leak and I have a bigger problems. The manifolds are corroding between the riser and the manifold joint, actually piece are flaking off…So I figure if this is how they look on the out-side, the inside has to be worse…correct?

My questions are…what’s the best to go, Ceramic coated, Aluminum or Cast Iron I read that Ceramic & Aluminum may not expand the same as the block and that this condition could cause leaks??

Any recommend brands...I see eBasicPower has them at a reasonable price, but are they worth the money?

Thanks….Al

 

[Haut Medoc]

Re: Exhaust Manifold & Risers

Yep, it's time.....
& I would change both the risers & manfolds.....
I would go for the cast iron from ebasic.....
Forget using aluminum in salt water.....
While the ceramic ones last longer, they are likely much more expensive......
You could probably do ebasics twice for the cost of OEM........JK

 

[crazy charlie]

Re: Exhaust Manifold & Risers

Wow !!!! You sure are ready.If you got that kind of life out of them then I would go with the ci as HM stated.They will surely be the most cost effective for you.I am about to order a set from Basic power myself.They have Osco and GLM for about the same price and it is a good price!! Charlie

 

[Reel Poor]

Re: Exhaust Manifold & Risers

Go with the GLM manifolds. From my personal experiance they tend to hold up better in saltwater.

 

[Don S]

Re: Exhaust Manifold & Risers

Go with the GLM manifolds. From my personal experiance they tend to hold up better in saltwater.

Better than what? ? ? ? OEM, Bar, Osco...... Were they all operated the same, flushed the same and treated the same?

 

[Reel Poor]

Re: Exhaust Manifold & Risers

Better than the Osco's that were mentioned in the above post. Like I said my personal experiance, meaning manifolds I ran on my own boats. The OEM and the GLM's didn't appear to start flaking apart as fast as the Osco brand. I'm not sure why they didn't hold up as well, maybe they have more carbon in them and cast iron with a high carbon content is more susceptible to degradation.

 

[Boating_Al]

Re: Exhaust Manifold & Risers

Guys thanks for your help….”Reel Poor” thanks for your explanation, this is what I was looking for. GLM from ebasic looks like the best way to go.

 

[ziggy]

Re: Exhaust Manifold & Risers

i don't have yer v-8, but i've been happy enough with the ceramic coated manifold and riser i got from www.perfprotech.com for my l6.
the one i got from them was made in canada. wonder where the glm's or osco's are made?
they were also pretty price competitive........

 

[andy1canada]

Re: Exhaust Manifold & Risers

Howdy from Canada!

Forgive my intrusion Gentlemen, but I too was thinking about aluminum exhaust manifolds for the new 4.3/MPI I'm about to order.

I've read a few comments about aluminum not standing up in the marine environment as well as cast or ceramic coated jobbies. (The new engine I'm ordering comes with ceramic coated risers I believe.)

I may not be able to order the new engine with an aluminum exhaust - so all this jibberish could be a moot point - but, in consideration of the terrible power-to-weight ratio of sterndrives (compared to todays outboards) it seems to me there could be a substantial weight savings by going aluminum.

What exactly is the problem with aluminum in the exhaust raw-water circut? Rots-out too quick, or what?

Cheers,
Terry Anderson
Victoria,BC
Canada

 

[Haut Medoc]

Re: Exhaust Manifold & Risers

Yup, salt water will eat it alive, real quick........
P..S........The extra weight is not that big a deal.....
Just stick your MIL up front........

 

[Irish Rogue]

Re: Exhaust Manifold & Risers

Re: Exhaust Manifold & Risers

HOLY COW!!!!

I was literally about to push the button to order an aluminum set. The weight advantage and corrosion resistance all seemed like a good idea. I am so glad I did a search for this in here and saw your discussions.

Thanks to all of you!

Irish Rogue

 

[FreeBeeTony]

Re: Exhaust Manifold & Risers

Re: Exhaust Manifold & Risers

Would also check out Dennis Moore on Ebay.............