And if it goes. what is the plan then?

I think the old merc stuff was fairly reliable. I have not seen
much out of the merc factory for the past 2 years that I thought was very reliable. Ilmor is a stand up company and
still put the dollars into their motor/drive programs. From what I have seen and heard, Mercury is starting to cut corners and warranty issues are a real problem now.
If I was building a new boat, it would definitely be Ilmor

Ilmordude and ilmorgirl rock!

Most people on this board are diehards so they have not only heard of Ilmor but are also familiar with their products. Out there in the real world that is not the case.

That being said, I think we will see that change over the next few years. I can tell you that living in Michigan it would be a no-brainer for me if I was building a new boat with 600-700hp engines, Ilmor all the way.

I've been boating for 25 years but not in high performance. I plan on running my 5.0 MPI's in my cruiser for more than 1000 hrs w/o rebuilding as i do change oil every 50 hrs. I run 3500 to 4500 rpm consistently. When a previous post mentioned the Ilmor's getting 500 to 700 hrs before rebuilding, I'm just wondering why this would be necessary. The boat I'm looking at has a single 625 Ilmor. I'm fairly certain I won't run over 4500rpm for long stretches ever though these can run 6000Rpm's. Is the rebuilding simply part of the cost of any high performance motor???

[QUOTE=Is the rebuilding simply part of the cost of any high performance motor???[/QUOTE]

Yes !

500-700 hours out of a 600-700hp n/a motor is a long time. 1000 hours out of a 330hp stock 7.4 is not unheard of in a cruiser. My dad had a 330 7.4 in a shrimp boat in the late 80's that seemed to run forever. It got run all day everyday between crab and shrimp season for years!!! Who knows how many hours it had. But that same 7.4 or even 502 based engine making 6-700hp won't see nearly the same amount of hours before needing some freshening up.

I'm not all that familiar with the Ilmor v-10 packages but I do have some knowledge of the viper v-10 and those motors are a beast!! I've seen them take a beating with out a problem. Call me crazy but I love the sound of a viper!!!

It is.

One can look at the cost of a high end boat in a very similar fashion to an airplane- the closer one gets to rebuild time the less price one can get for the rig.

Performance NA mills hammer the valve-train spinning high RPM's for long periods of time.

For a sake of comparison on the high end of Mercury super cat 850's and earlier blown mills run on a solid roller cams "ask" for valve lash inspections every 15-25 hours. See Mercs own guidelines for maintenance and rebuilds.

http://www.mercuryracing.com/_media/pdf/freshenup.pdf

The Ilmors have 20% more surface area to spread X amount of hp across thereby reducing load per cylinder compared to a V8.
A simple leak down test should tell you how relatively fresh the mill is and you may get many more hours between rebuilds than 6-700.

500 hours is a typical cycle for the top end of a 500+HP Marine V8.

Uncle Dave