Stainless Marine 525 exhaust
 

Seems to be a hot topic lately and while I don't currently have CMI headers on my boat will most likely have them on my next.With everything I have heard about them they will not be there long.There seemed to be different opinions on if you could use Stainless Marine exhaust on the 525s so I spoke with Jerry at Stainless today.Yes you can but you have to re-drill and tap the heads as they are not GM heads the bolt pattern is different.Stainless Marine has a jig to do this and they will lend it out (with a deposit) to anyone who buys there product.There are a couple of other minor modifications like moving the water tank but the also offer the bracket for that.

Attachment 436025

I assuming that this will work with the GEN III manifolds also?
Sounds like a good solution, especially if you can use the GEN III manifolds.
Dean

Once you drill the heads its a standard GM pattern you can use anything.

Good idea, however I can't imagine drilling a non staggered twin set up with the engines mounted, hard enough just getting the exhaust off.

Still no replacement for the sound of a true header :)

the benefit to stainless marine is that they last a long time and don,t leak like the cmi's.
i think i would rather loose a few pony's to stay reliable and not blow my motor up and it cost lot's of $$$ to fix

mike

if you have a blower and gen III's you don't lose anything hp wise.

What about making a half inch adapter plate to adapt the bolt pattern?
The Big tubes we use have those to allow for bolt access, they should be available or fairly easy to make

Stainless Marine are gonna be my chioce!

HOW ABOUT JUST MAKING THE STAINLESS MARINE STUFF FIT;;;JUST LIKE STOCK:eek:

+1 to what he said.

I'm going 1 better, (IMHO) with KE's headers. True 32" runners that won't CRACk, and will out perform the CMI's. Only drawback is that they are LOUD, (Drawback as far as our neighbor's on our canal are concerned!:drink:) Plus they are not the Eye candy the CMI's are......

But Stainless Marine is a great manifold, no doubt, I just have had great experinces with KE's headers.
Dean

Either way the KE 32" or the Stainless Marine are a no brainer. With Stainless Risers the SM stuff looks nice and does last a long time. THe GEnIII for big CU.IN. engines flows as good as any header on blower stuff.

That's the 1st I've heard of that, thanks for the info, I will keep an out for that problem, and I will look at them this weekend, since they are now sitting in my garage.
Dean

Oh yeah I know about the H2O flow requirements, I always installed new Raw water impellers every year and never had a problem. Got to make sure the header fills with H2O ASAP.
Dean

Are you changing yours out right away?

It's a hard pill to swallow initially, but probably money well spent in the long run.

Ive got 10 years/400 hrs on mine (knock on wood).

Was there a specific spot on the manifold where they were alleged/known to have cracked?

Not sure Scot. But I can sell the CMI'S and put Stainless Marine Gen III's. Gotta make sure the Gen III's will not hit on the insides. Engines are closer together than stock.

I had 7+ years and ~ 400 hours in 100 % salt water, flushed everytime, and NEVER a problem on my 1st set.
Dean

CMI/Mercury should just step up and recall their Headers. Replace them at minimal cost to the end user. Lets just say have the end user pay for the labor and shipping.

CMI will check them out for you and repair them if necessary. (at a minimal cost)

Here is the response I got when I inquired:



MY INQUIRY:

I own a 2005 Nordic Heat with a Mercury 525 efi. I've heard horror stories about the 525/CMI header issue. It is my understanding that CMI will inspect and repair if necessary. Can you please provide details of what I need to do and how to make arrangements for this to happen. The boat is now being winterized and I thought it would be a good idea to do this at this time. I have had an issue with a leaky header recently and luckily it was caught in time and no apparent damage has been done. To avoid future issues, I would like to have CMI inspect them for me.





RESPONSE:

They can be sent to our facility for inspection and testing. At that time we can then determine the issues with them and recommend what is needed. The average is about $250 per pair for testing and a light clean up.

Our address is:

1315 County Road G
Neenah, WI 54956

Include all of your contact information with the headers so we can reach you after they have arrived.

Thank You,

David Rank
Custom Marine
920-720-4225
www.custommarine.com

Does any body know anything about the hardin exhaust line is this any better than cmi junk

I have used the Hardin Big Tubes. I think they are the Hurricane's. I have a set that is now over 2 years old and going strong. They were about half the price of the CMI Big Tubes. So far I love them and would not hesitate to use them again.
Eddie

Changing the CMI 525efi sweepers to a non -long tube header will loose some power on the 525efi and definitely some torque in the mid-range. You should look at CMI's new GEN-X replacement header for the 525efi these can be ordered in the same drilling and will not suffer the cracking problem that the 05-06 Merc 525 CMI headers do and should be a direct bolt in replacement. I have no expierence with the Hardin units and I hear they can be a good header, but it depends as you might want to research the Hardin headers here on OSO>

Best Regards,
Ray @ Raylar

Well then they could market them as a direct replacement exhaust for the 525 with no modifications needed.
I would bet they would sell a larger quantity and recoup the initial cost rather quickly. Just look at how many are looking here for replacements.

As Ray had said....CMI's new GEN-X replacement header for the 525efi.....

If the history is there you can't argue with that!!

Those would be the nicest choice, but at what cost per set?

i agree .i been runnig sm for 20years now they are on a 540 with 718ponys

my dry gen 2s are very loud on my 509 650hp motor louder than the 525 boats. gen 3s come in 4 1/2'' or 5''. the hardin marine headers look nice I bought a new pair for my 572 blower motor cause I got a great price, other wise I was getting the gen 3s 5''. my gen 2s I bought from a fellow race team in 1994 after 4 races he switch to cmi headers and pick up zero in speed from the cmi headers and wished he saved his money and kept the gen 2s. hope my hurricanes by hardin stay together there hugh.

+1 Thats why we went with Stainless Marine instead of hearders. There two types of headers the ones that are leaking and the ones that are going to leak !!!!!

I think mine sound just fine. 4 1/2" dry tails. :)
[youtube]http://www.youtube.com/watch?v=xL4bE4Oj04A[/youtube]

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panther your motor sounds good . here is mine http://www.youtube.com/user/SuperBaj.../0/XKQj2fy91BU