525EFI Header Failures - CMI vs Hardin - All failing
08-31-2014, 12:03 AM
#21
Registered
Everything in boats has its issues however breaking a flange is nothing compared to grenading a motor. Again the cost to remove the heads to drill is still cheaper than a full rebuild. Ill take that piece of mind all day long
08-31-2014, 07:45 AM
#22
Registered
Platinum Member
How about having to pull heads or engines to gain access to install fixture to re drill bolt pattern on a twin side by side or even a tight single? Or is it possible to gain enough room to install fixture and re drill? Most people would have to pay a shop to do that. I had SM on a staggered 33 Powerplay and the forward motor broke two sets of flanges off manifolds at tail pipe and manifold flange, where clamp goes, in under a 100 hrs. The set up was custom built by Stainless. So they are not unbreakable either. Yes it did have long tail pipes and were well supported. Powerplays are well built boats but I guess it was still flexing because of length. Stainless did warranty the first pair. I still think they are very good manifolds and customer service was very good. But you will still have to add in the extra install expense for 525-700 SCI applications and they are not indestructible. As we all know salt loves aluminum too. I now have 600SCI's, in my Spectre, with good ole proven CMI etops adapted by Teague Custom Marine to fit header flange bolt pattern and bungs installed to bolt antifreeze reservoir to. I sold the sweepers off the 600SCI motors and purchased etops and plugged right in to my existing tail pipes from my 575 SCI's. Old etops were 11+ yrs old and sold with motors. Never had an issue.
08-31-2014, 08:00 AM
#23
Offshoreonly Advertiser
Offshoreonly Advertiser
Here's a picture of the SM Jig. We use a right angle drill when the engines are in the boat.
__________________
www.diamondperformanceparts.com
[email protected]
http://www.facebook.com/pages/Diamon...07878772615803
302-521-0123
The Best Parts & Service At The Best Price
www.diamondperformanceparts.com
[email protected]
http://www.facebook.com/pages/Diamon...07878772615803
302-521-0123
The Best Parts & Service At The Best Price
08-31-2014, 09:19 AM
#24
Airking
VIP Member
Join Date: Aug 2004
Location: Stafford Va.
Posts: 452
Likes: 0
Received 0 Likes
on
0 Posts
Yes Teague is a dealer for CMI and will modify them. They weld about a 1/4 to 1/2 inch, something like that, talk to them for exact modification length, to end of flange and re drill holes to correct location. Then install side bungs on starboard header to be able to modify your antifreeze reservoir bracket. Looks just like they came from CMI made that way. Dave at MDG in MD did the install of headers for me and the tank bracket mod. But if you had the sweeper style header on the boat you will need tail pipe modification. I already had etops on 575sci so they fit right up to existing tail pipes. You can see the etops and bungs in the pic I posted. Double click on pic to enlarge.
Last edited by Boater8987; 08-31-2014 at 09:39 AM.
08-31-2014, 09:40 AM
#25
Registered
I once found an old spreadsheet on here that had dyno info from lots of exhaust types. SM, Imco, CMI, etc. If no one has found by the time I get back to the office I'll post it.
08-31-2014, 01:35 PM
#26
Registered User
Gold Member
Join Date: Sep 2010
Location: buffalo, ny
Posts: 214
Likes: 0
Received 0 Likes
on
0 Posts
Which manifolds is stainless marine using to replace the sweeper headers? I had the old style sportubes and just replaced them with the gen 3 manifolds. The manifolds pretty much perform the same as the headers did. I don't have very many hours on mine, but in the few hot passes I've taken it seems like I'm gonna be within 1 mph. That's on hp 500's with small blowers
09-02-2014, 09:59 AM
#27
Registered
09-02-2014, 11:09 AM
#28
Registered
Note: the more 'cam' an engine has, the more 'headers' (properly sized of course) are important. Yes, the KE manifolds are true headers.
The 525 EFI has a buttload more (yes, that's a measurement) cam than the HP500 had.
The 525 EFI has a buttload more (yes, that's a measurement) cam than the HP500 had.
09-02-2014, 11:21 PM
#29
Registered
SM makes a great product but they're not going to make more power in the 4000+ rpm range on a 525. The loss may be minor enough for the peace of mind trade off however, but that is subjective. That being said I'd run SM or KE exhaust, but sooner or later all manifolds will rot from the salt water.
Last edited by onesickpantera; 09-02-2014 at 11:25 PM.
09-03-2014, 11:53 AM
#30
Registered
Join Date: Nov 2004
Location: Palm Coast, FL
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
Hey Guys for what its worth I just don't know of a product at least a header that if not properly flushed and or treated with Salt Away that will survive in a salt water environment. So no matter if we build them or CMI or well who knows who else, you need to know salt water is bad corrosive stuff and kills all stainless steel exhaust..
The headers in question here were returned to us for evaluation as prior to seeing them had it been a product failure even well out of warranty we would have stood behind them but the headers returned to us for repair were literally crumbling as in rotten.
We just can't control mother nature and how a product is cared for. So while were using the very best US Made 316L heat treated stainless steel you all need to know it still fails over time. This isn't news to many of you but to some based on the amount of money they spend on a product means it must last forever well just not so in the exhaust world.
While the possible cure would be Titanium the cost sky rockets to over triple the cost. We do know there's a real 525 direct bolt manifold system with NO DRILLING required to show its face in the up coming future as well. But honestly if neglected almost everything will succumb to the damages of corrosion.
The headers in question here were returned to us for evaluation as prior to seeing them had it been a product failure even well out of warranty we would have stood behind them but the headers returned to us for repair were literally crumbling as in rotten.
We just can't control mother nature and how a product is cared for. So while were using the very best US Made 316L heat treated stainless steel you all need to know it still fails over time. This isn't news to many of you but to some based on the amount of money they spend on a product means it must last forever well just not so in the exhaust world.
While the possible cure would be Titanium the cost sky rockets to over triple the cost. We do know there's a real 525 direct bolt manifold system with NO DRILLING required to show its face in the up coming future as well. But honestly if neglected almost everything will succumb to the damages of corrosion.
