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Mercury Racing Headers Lifespan?
I've started the hunt for a go-fast again. The hulls I'm looking at are all custom builders from the west coast and many of them have bigger power in them than the Mercruiser stuff.
Many are equipped with the 525 and 600SCI that have the stainless individual tube headers. Since I'm using this boat in saltwater (but will flush after every use) I started to do a web search on the longevity of these headers in salt. What popped up was a bunch of threads back in 2010-2013 where people had headers cracking and the water back filling their engines. So my question is, was this an isolated problem for a particular period and if so what years were affected? Thanks, Ken |
This has been covered extensively in the Tech forum. If you do a Google search of CMI headers and OffshoreOnly, you’ll get a lot of information. My understanding on the issue is that Mercury Racing specified a thinner-walled material be used by CMI in the construction of the headers. This led to issues with cracking. Long tailpipe runs were also listed as a factor. I have a set of CMIs on my 502s that we’re purchased from CMI well over fifteen years ago... no leaks. I flush them religiously to probably the point of overkill. I also pressure test them at least every other season. I have thought about setting up drains as a means of prevention if there ever was to be a failure, but haven’t gotten that far. I may take care of it this offseason. |
Originally Posted by Stitch King
(Post 4705672)
I've started the hunt for a go-fast again. The hulls I'm looking at are all custom builders from the west coast and many of them have bigger power in them than the Mercruiser stuff.
Many are equipped with the 525 and 600SCI that have the stainless individual tube headers. Since I'm using this boat in saltwater (but will flush after every use) I started to do a web search on the longevity of these headers in salt. What popped up was a bunch of threads back in 2010-2013 where people had headers cracking and the water back filling their engines. So my question is, was this an isolated problem for a particular period and if so what years were affected? Thanks, Ken What boats are you looking at? |
ToMorrow, Thanks for the info. We're looking at party cats like the Nordic 29, Eliminator Fun Deck and others. The plan is to travel out west and check out the used inventory and even discuss building a new one from the mold.
I'm getting too old to want to deal with problems and the headers seem like they are a potential failure mode. Since I don't need to be the fastest guy on the lake or ICW I could really care less about the power especially if it's going to bring headaches. However, if we look at used we'll need to be open to variations of engines and need to be prepared with the info. |
Originally Posted by TomZ
(Post 4705689)
This has been covered extensively in the Tech forum. If you do a Google search of CMI headers and OffshoreOnly, you’ll get a lot of information. I came to a DISCUSSION FORUM to ask a valid question. (I even gave it it's own line in my post.) Discussion Forums DIE when nothing is discussed and there's no traffic to the site other than the search and leave mentality you are promoting. If I'm off here please feel free to repot me to a Moderator and have me banned. |
Originally Posted by Stitch King
(Post 4705730)
This is a completely useless reply. If you had read my post you would have seen I'd done the searches and have turned to the experts for a specific question.
I came to a DISCUSSION FORUM to ask a valid question. (I even gave it it's own line in my post.) Discussion Forums DIE when nothing is discussed and there's no traffic to the site other than the search and leave mentality you are promoting. If I'm off here please feel free to repot me to a Moderator and have me banned. |
Long story short, again.
CMI spec'd a "best" header. Mercury said they only want a "mediocre" header, basically just good enough to get through the warranty period. "Best" was too expensive. CMI bucked, but then caved given the size of the revenue coming in from Mercury. CMI received a bit of a black eye for a while, but most folks know the real story. CMI makes and sells a "best" header direct to consumer. As do others. Can't comment on lifespan, because it's a crap-shoot. Sometimes the have issues right away. Sometimes they last 15 or 20 years. A lot depends on the design of the boat, length of tailpipe, vibration, and how they are supported. |
Originally Posted by Stitch King
(Post 4705730)
This is a completely useless reply. If you had read my post you would have seen I'd done the searches and have turned to the experts for a specific question.
I came to a DISCUSSION FORUM to ask a valid question. (I even gave it it's own line in my post.) Discussion Forums DIE when nothing is discussed and there's no traffic to the site other than the search and leave mentality you are promoting. If I'm off here please feel free to repot me to a Moderator and have me banned. I provided a means of searching for a plethora of information that’s been discussed around this topic. The site’s internal search function doesn’t work well, and using Google you can get more relevant information. I also gave you my understanding of the issues as well as I my experience with CMI headers. So what part of my response was useless?? Good luck with finding a boat there buddy. |
Originally Posted by Stitch King
(Post 4705730)
This is a completely useless reply. If you had read my post you would have seen I'd done the searches and have turned to the experts for a specific question.
I came to a DISCUSSION FORUM to ask a valid question. (I even gave it it's own line in my post.) Discussion Forums DIE when nothing is discussed and there's no traffic to the site other than the search and leave mentality you are promoting. If I'm off here please feel free to repot me to a Moderator and have me banned. |
Originally Posted by Stitch King
(Post 4705730)
This is a completely useless reply. If you had read my post you would have seen I'd done the searches and have turned to the experts for a specific question.
I came to a DISCUSSION FORUM to ask a valid question. (I even gave it it's own line in my post.) Discussion Forums DIE when nothing is discussed and there's no traffic to the site other than the search and leave mentality you are promoting. If I'm off here please feel free to repot me to a Moderator and have me banned. OSO members - Beware you may get flamed for helping this guy. |
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