I had a discussion on this subject with Paul Ray, the president of Ilmor. Here's what he had to say, http://www.boats.com/boat-content/20...-ilmor-engine/.

By Ilmor telling people not to super-charge their product will make people want to do it even more !

[I][QUOTE=C_Spray;"Would they offer any ideas as to what it would take to convert your 625's to 7-10's? If was as simple as a cam change and ECM programming, it wouldn't be too bad. On the other hand, if it involves head work and a different crankshaft or something, that's a whole nother story.
Still, I can't [/I]help but think that a blower development program would have to be very expensive."

I believe the 710 is a blue printed & balanced hand built engine w/ port work while the 625 is assembly line built w/o any porting. If you were due for a rebuild anyway this might be a viable upgrade but Ilmordude would know best!

Ian Hawkins called me today regarding my engine, so I asked him. The 550 and 625 Gen 3 engines used a different rotating assembly from the 7-10, so to try to upgrade is problematic. This would not bode well for a blower upgrade to your 625's either. Sorry to pass on bad news...

Apparently, if you buy one of the new 650 or 725 Gen 4 engines, the internals are the same, so an upgrade would potentially be simpler.

So typical of boating: No cheap, simple, reliable solution for speed.

Whose tag line reads: "Cheap, Fast, Reliable. Pick two."?

I guess so--if those people happen to think like rebellious children who don't mind wasting a lot of money on something that will break.

Paul Ray, the president of Ilmor, has zero investment in telling anyone not to try to supercharge his company's engines, other than to just present the facts and prevent people from wasting time and money. I mean, it's not as if Ilmor currently has (or will have in the near future) a big-horsepower blower engine it needs to protect.

C-Spray spoke to Ian Hawkins, who said the same thing in a more detailed way.

I'd take the advice of Ray and Hawkins.

Matt,

It was my understanding that Ilmor did not recommend supercharging its current engine package because of the relatively high compression ratio, and the internal parts (rotating assembly), that were designed for a naturally aspirated configuration.

You would be mistaken if you thought that Ilmor is not in the testing/development stages of both supercharged and turbocharged marine motor applications.

While Mercury Marine did indeed beat Ilmore to the punch with its revolutionary 1350 motor, you can count on the fact that they (Ilmor) are preparing to do battle with Mercury at every performance horsepower level, and that their highter horsepower motors will be forced induction of some kind.

Ilmor roots lie in Indy car motors... have you ever heard of a forced induction indy motor? ... :D

Chris

Could you imagine what our founder, Mario Illien, could draw up for a big ol marine engine. I mean, our lobby would give anyone remotely interested in engines, a big ol woody.

800lbs , Carbon Fiber, Ten Cylinders..................:coolcowboy:

It's already ready to go, Nick. Go back to 1994, call up the drawings of the MB500I pushrod engine and make it 600 cubic inches instead of 209. That thing made 530 ft-lb/900 hp all day, so I guess that we'd have 1500 ft-lb/2600 hp all day. I'd be like the rail car dynamite scene in Butch Cassidy: "Think you used enough...?"

My last post felt a little rude so I deleted it. Sort of. I can't find the delete button.