iron exhaust manifolds-how long do they last?

[shilo]

The stock Merc cast iron exhaust manifolds - any ballpark figure on how long they last in freshwater? I have a 1990 Sea Ray 220 Cuddy with the 260hp merc and just under 400hrs. It appears that the exhaust manifolds and risers are the original and I'm wondering if I should replace them before anything bad happens. Is there any sort of time frame or life expectancy for these?

 

[Quint4]

I believe mine are original...I took them off and inspected them a few months back...they looked OK...I replaced the gaskets and re- torqued to spec....I have the same year engine as you....all freshwater use....you should remove and inspect them every other year...the gaskets are a common failing point.

 

[boatdoc100]

They will last indefintly in fresh water as long as they are winterized properly. I work on boats from the 1950's with original manifolds.
Brad
Pflieger Marine Services

 

[Sundancer]

Mine are the original. We've never even had them off to check the gaskets! It's just not needed around here. The original paint is still on the bolts holding them on. We've got 460 hours on our 1987 454 Merc.

 

[FYN409]

Ah, music to my ears. I was starting to get concerned myself with all of the talk around here about riser replacement. I have an 88' with the 454, it has been in freshwater all of it's life and as far as I can tell the risers have not been off. Until comming to this forum I had not heard of removing them yearly for inspection. I can completely understand if in saltwater use, but in freshwater?

Mine are the original. We've never even had them off to check the gaskets! It's just not needed around here. The original paint is still on the bolts holding them on. We've got 460 hours on our 1987 454 Merc.

 

[Sundancer]

Ah, music to my ears. I was starting to get concerned myself with all of the talk around here about riser replacement. I have an 88' with the 454, it has been in freshwater all of it's life and as far as I can tell the risers have not been off. Until comming to this forum I had not heard of removing them yearly for inspection. I can completely understand if in saltwater use, but in freshwater?

I LOVE freshwater boats!!!

 

[FYN409]

No kidding, boating is expensive enough, then throw in all the maintenance issues with salt water. :wow:

While the winters are a bear, having the freshwater ocean 30minutes away from home is real nice. :thumbsup:

-Ryan

 

[sbw1]

Not only will the exhaust manifolds last the life of the engine but the risers and elbows too so long as you boat in fresh water. I was on a friend's 1989 Silverton with 454s Friday night. He has never touched a thing which is pretty much the norm around here. Winterizing properly is the key if you do cold storage. Otherwise you really don't need to worry about this issue.

 

[Quint4]

I bought my boat used and wanted to establish a "baseline". I was unsure of the complete history. I know water ingestion is probably the biggest killer of marine engines so a few hours & $15 bucks for gaskets was worth my piece of mind.

 

[Sundancer]

I know water ingestion is probably the biggest killer of marine engines so a few hours & $15 bucks for gaskets was worth my piece of mind.

Ingestion implies it was taking water through the carb. I'd say it's more like a suppository!!

 

[Quint4]

uh...ok.

 

[rondds]

the mechanic at my marina told me that in a fully closed cooling system, manifolds should never really give any problems, even in salt water. risers, DIFFERENT STORY. i pulled my risers to get a baseline reading last winter and to replace the gaskets- boat has been in salt and brackish water since birth - the risers were mint (but were probably done by the previous owner before sale). the innards of the manifold, as far as i could see, were in very good condition. apparently, the gasket btwn the riser and the manifold is a weak link that can fail over time, allowing seawater to get into the manifold - VERY BAD THING. i also flush the engines at the end of each weekend. does that now make me a fresh water boat?? :huh: