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riser /elbow life??

T

tedcurtis

New member
trying to figure out the life of risers and elbows on a crusader 454 // located in san diego..// what i call a half system,, raw water to riser and elbow,, engine cools the mainfold,, any advice would be great,, thanks tedc
 
you may term it a half system but it is properly referred to as a full system....the elbows will Always be on the raw side....on a half system, only the block is included in the closed (antifreeze) side...a full system adds the manifolds to the closed side....finally, the risers, if equipped, usually go in the raw side. And 2X on Jeff's number
 
Re: riser /elbow life?? How about the manifolds?

makomark said:
you may term it a half system but it is properly referred to as a full system....the elbows will Always be on the raw side....on a half system, only the block is included in the closed (antifreeze) side...a full system adds the manifolds to the closed side....finally, the risers, if equipped, usually go in the raw side. And 2X on Jeff's number
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I have heard different opinions, but want to throw this out here:On a full FWC engine, should you replace both the risers and manifolds every five years?

I had a boat with 2x 454s and every 5 years replaced the risers and manifolds (pretty expensive). I read some opinions that since the manifolds are FWC, they will last a lot longer than the risers (or elbows).

Some say change the mani's every time; others say every other time you change the risers; some say the mani's should last the life of the engine.

I now have a boat with a single 5.7MPI...it's coming up on time for me to replace risers....so am contemplating this....thoughts?
:confused:
 
Re: riser /elbow life?? How about the manifolds?

thefishtank said:
I have heard different opinions, but want to throw this out here:On a full FWC engine, should you replace both the risers and manifolds every five years?

I had a boat with 2x 454s and every 5 years replaced the risers and manifolds (pretty expensive). I read some opinions that since the manifolds are FWC, they will last a lot longer than the risers (or elbows).

Some say change the mani's every time; others say every other time you change the risers; some say the mani's should last the life of the engine.

I now have a boat with a single 5.7MPI...it's coming up on time for me to replace risers....so am contemplating this....thoughts?
:confused:
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If your 454's were FWC, replacing the manifolds every 5 years was a big waste of money. If the boat was operated mainly in fresh water, you should get more than 5 years out of the risers and elbows.
 
Thanks Craig. The old boat (Luhrs 34) was operated in S. FL saltwater. Had lost one engine from hydrolock when the original elbows went, so always erred to the side of caution after that.

My current boat is an IB Mako 236; still in S. FL. Getting to the manis will be a major PITA..it is shoe-horned in under the console, although the risers will be easy enough to get to.
 
Always good to err on the side of caution. I think in salt water, it would be good to replace risers and elbows every 5 years. I currently go ten years on mine but I'm mainly in fresh water at the head of the Chesapeake Bay.
 
I got 28 years on the originals in a FWC Tiara, but pretty plugged up now. Will be doing risers/elbows on both engines in spring.
 
Tiara 2900 ten years ld with 6.0L engines with 550 hours all in salt water. Just bought it and had the risers replaced. The original risers were heavily rusted on the inside with passages blocked by thumbnail sized pieces of rust.
 
It just amazes me that someone has not come up with an alternative to cast iron for these things; porcelain, ceramic, high temp plastic, etc.?

It is just crazy that us boaters are dumping thousands into this stuff every 5-10 years.
 
There are several options to cast iron....none are cost-effective as a replacement, at least from an OEM perspective. Porcelain and ceramic are insulators and impede heat transfer...the other thing to remember is the recreational marine industry has been on a downward trend ever since gasoline went over $2/gal....add to that the new EPA requirements and the end result is little if any research money....if you don't wanna change risers and elbows, find somebody to get you a set of stainless parts...they won't be cheap..
 
craig_collins said:
Always good to err on the side of caution. I think in salt water, it would be good to replace risers and elbows every 5 years. I currently go ten years on mine but I'm mainly in fresh water at the head of the Chesapeake Bay.
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I am in full agreement that 5years is the maint. period for risers....but still wondering about the manifolds...?
 
FWC cooled manifolds live in an environment that is similar to that seen by the heads (operating temps, corrosion, etc.) except they do not have valve seats to wear or fail and they do not see combustion pressure stress and overheat stress. So it would make more sense to change out heads periodically than exhaust manifolds.....and no one does that!

Salt water cooled elbows and risers are a different story but don't worry about the manifolds.
 
Has anybody here ever tried coating a set of new risers and elbows before installing? Is it possible to powder coat cast iron parts?
 
CaboJohn said:
FWC cooled manifolds live in an environment that is similar to that seen by the heads (operating temps, corrosion, etc.) except they do not have valve seats to wear or fail and they do not see combustion pressure stress and overheat stress. So it would make more sense to change out heads periodically than exhaust manifolds.....and no one does that!

Salt water cooled elbows and risers are a different story but don't worry about the manifolds.
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interesting point about the heads..thank you for your input!
 
did one set in alum-a-coat and another set in ceram-a-coat.....ceram-a-coat better product but haven't found anything to endure the sustained heat seen at the bottom where the exhaust ports are....and the sole purpose of the "experiment" was to see is we could maintain the cosmetic appearance of the exterior surfaces only...
 
Interesting, I have 2 full sets of brand new risers and elbows here that I may look in to having coated with something. I think our boat accumulates a lot of the plugging up from sitting extended periods of time, it is only used about 3 weeks a year, with lots of idling, heat my not be a huge factor.
 
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