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Cmi Headers/525 Efi Problems?

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Old 02-07-2010, 10:44 PM
  #91
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Question Lets hear from an Expert?

I think every performance boater who is considering a set of or has stainless headers on their boat needs a great explanation from a metals and welding expert here on OSO so they can understand why there are specific types of stainless materials and quality of stainless that must be used and there is a specific welding process at a specific temperature and a heat treating and conditioning process that should be done to stainless welds like those on marine headers that will condition these welds and stainless material so that this type of weld and material cracking is lessened or eliminated.
I am not sure what processes or actual material CMI uses on these headers prior to fabrication during welding or after welding and fabrication, but I do know it should be very specialized and pro-active when it comes to developing a leak and crack free stainless marine header.
I also know that re-welding the headers for repairing cracks and leaks must also be done by special processes if the repair is to last.
I am hoping someone reading this post knows someone or some entity who can explain the real proper technology and processes that should be used on stainless when welding to prevent these problems. I
am not a metals or welding expert so I would really like to hear from a specialist who is who can concisely explain the proper procedure and process that should be used to hel p lessen and maybe prevent these problems from arising.
Who Da Man!

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Ray @ Raylar
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Old 02-19-2010, 04:18 PM
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Do later build 525's have cool-collars? If so, what year did this start?

Thanks

Last edited by rj45; 02-19-2010 at 04:25 PM.
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Old 02-19-2010, 06:01 PM
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I have several 525s in shop for rebuild due to header leakage(around 100hrs) after pressure checking leaking up in collector,As Ray stated re-drill head with fixture easy to drill aluminum and then install any header or manifold on market,if you change to manifolds will loose a little hp,the ke maybe not,Jerry at stainless marine has already done this and has a fixture that makes it real easy,I think I am going to borrow it and do some dyno testing to figure out results,as far as the merc warranty after 1 year there is none,not sure what the manifolds will do to the tune probably make it a little richer which shouldn't hurt it,the 525 is as great engine with little issues except exhaust,until cmi gets it right i wouldn't recommend installing them on the 496 too risky trashing a very reliable engine for a few hp,On a different note the cmi elbow tops are amazingly reliable have pressure checked many pairs close to 10yrs old and 300-500hrs no leaks,they have got them down pack,they are now offering there own 525 header replacement built to there spec not the same as merc but will replace the merc,they are in there new catalog,they are working on pricing and distribution
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Old 02-19-2010, 06:13 PM
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Quote:
Originally Posted by MDGperformance View Post
I have several 525s in shop for rebuild due to header leakage(around 100hrs) after pressure checking leaking up in collector
Are you saying that there's a specific point where they tend to leak?
And if so, where is it exactly?
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Old 02-19-2010, 06:30 PM
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Quote:
Originally Posted by Raylar View Post
I
I also know that re-welding the headers for repairing cracks and leaks must also be done by special processes if the repair is to last.
I am hoping someone reading this post knows someone or some entity who can explain the real proper technology and processes that should be used on stainless when welding to prevent these problems. I
am not a metals or welding expert so I would really like to hear from a specialist who is who can concisely explain the proper procedure and process that should be used to hel p lessen and maybe prevent these problems from arising.
Who Da Man!

Best Regards,
Ray @ Raylar
May I first say I enjoy reading all your posts Ray. I would also like to say we have seen issues with E-tops and what I will call the 525EFI header. All our experience is with salt water boaters. I do not like posting about things because it always turns into "crudge" match it seems. The E-tops seems to go at the flange end first. The 525's at the collector end. I have actually seen holes away from the welds in the "parent" metal for no reason at all. We all know the repairs are done in Argon atomosphere with a good filler rod, ala 347SST, and with a person with lots of experience. I have tried to point out some concerns to CMI, no comment. There are concerns with the clearance of the distributuion tubes being welded into the outer tubes into the flange area also. Have you ever noticed why the "bumps" inside the primary tubes in the flange area? Have you seen bluing of some of the outer tubes but not all of them? Have you seen brand new 700SCI engine with brown/golden headers?
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Old 08-03-2011, 06:02 PM
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Quote:
Originally Posted by Raylar View Post
I think I am going to design and offer a drill and tapping kit to fit the Mercury HP525 cylinder head so you guys can drill and tap the two added exhaust flange holes needed to buy and use some of the many other brands of crack free headers and header manifolds that are in the market which should eliminate this cracking/pinhole issue which appears to be damaging a moderate number of Mercury HP525's. Its nice that CMI seems to be paying for some of the actual header repairs for some users, however the engine damage, potential engine damage is not covered and obviously that is going to be the big expense and issue.
Give us some feedback here and let me know if there is enough interest in this type of refit kit in the market that we can justify making one available.

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Ray @ Raylar
Ray-
Was this ever developed?
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Old 08-04-2011, 01:31 AM
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Wink Lesser of a possible evil??

No, we have not done such a kit, as we did not get enough interest to justify the development. In some ways I am not sure I want to put that type of tool in to many hands anyway as some might just make a mess of their heads due to lack of careful work and knowledge. Then the only thing they remember is we made the kit!

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Old 09-09-2011, 03:11 PM
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Saw these at the SCOPE poker run.......interesting!




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Old 09-10-2011, 01:58 AM
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Tried looking up American Hi-Tech on the net but came up with nothing. You have a link?




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Saw these at the SCOPE poker run.......interesting!




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Old 09-10-2011, 02:25 AM
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Here you go

www.hitekmarine.com.au
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