Ilmor Headers
 

Are the headers on the 625 made by CMI? If so, have there been any reported failures similar to the Merc/CMI debacle?

Im selling a 525 boat to get away from this constant worry, and looking at a 625 boat. Could just be jumping back into the same thing maybe.

If there have been any Ilmor must have taken care of them, because I havent heard anyone screaming and I own and have been following ilmor threads for the last 2-3 years.

Question why would you sell a whole boat over an issue with the exhaust system when you could simply replace it with a either a "real" cmi exhaust, lightning, stellings etc, or a high quality manifold system?

Uncle Dave

I guess I should have said one of the reasons. Going from single to twin is the main reason, but not always worrying about 525 headers is side benefit I guess.

Its hard to describe how good the ilmor mills are.

I wouldn't worry about a thing.

CMI can build whatever the vendor wishes to cut a check for and I suspect ilmor did not cheap out on the spec.

Uncle Dave

Yes there have been. Or at least in my experience. We have 3 Ilmor motors.

2 headers on a 700 have cracked where the tubes enter the collector and started leaking water. Now I have the same crack on the header of a 625. Hoping this one can be repaired.

I have had two sets of headers that cracked also. But these were prototypes!! They cracked where the inside header tube is welded to the collector. What happens when they crack is the motor ingests water. I cut all four collectors off and rewelded all the header tubes back up, even if it wasnt cracked and havent seen a problem yet. They have around 600hrs on them altogether. It is a process to repair them but it is better than buying two sets!! I talked to Ilmor on this and they said the earlier headers had round collectors and were not as strong. The late model ones have the pentagon style.