The boat is in Havasu and I will get photos next time I am out and post them up. The water is picked up from an existing sea strainer bucket in the engine compartment. The gear oil is moved through the cooler with two braided ss hoses. These are drilled and tapped into the upper gear case of the XR drive. All of the gear oil is moved through the cooler with a 12 v pump.

Thanks,

Dan

Good read! I have a 600 in my boat and actually blew a lower up with the motor still stock...I have since done the whipple upgrade.

I also have a friend with 600's in a Flame with the stg 2 upgrades running XR drives and has had no issues for 180 hours....

Update at 403 hours.... no problems runs perfect. I just ran it last weekend 94 mph without pushing it. No oil consumption, no noise. BUT.... I decided based to do a head rebuild over the winter. I know that at a minimum I need valve springs but since I want to be preventative I am rebuilding the heads entirely. I thought about changing the cam but decided against it. The boat is plenty fast and runs strong. I don't need to manage more torque through the drive. In summary I have had a whipple stage 2 running this motor for over 300 hours with no problems. I would say the max rpm that I ran is 5800... 5900. I am trying to get 7 more years out of the motor without a complete rebuild. That would put me at 750 to 800 hours. What do you guys think? Am I wasting money ? Or being wise?

We are refreshing our NA 500 ci motors this winter with 90-100 hrs. We have a lot of hours at 6000-6500 RPM. I think you are making a good decision to freshen the motors now before something in the valve train fails. If you have the engine out, you might consider dropping the oil plan to just take a look at one rod bearings to confirm all is good.

IHave you ever had an IAC ( idle air control valve) go bad? I have heard of them going out but I haven't had one go bad yet, been thinking about carrying spare.

No problems with the IAC valve. Probably a good idea to carry a spare..

Do yourself a favor and change it as part of maintenance or go thru this and it shorts out PCM aka ECU like it did mine. Keep the old one in boat for a spare to get you home. They are not very expensive you can get at rockauto.com $39.79 or local parts house for cheap the delco part # is AC423.

http://www.offshoreonly.com/forums/g...-no-boost.html

Good advice from an old salt right there!

To add more IAC info:

The IAC valve is listed also for :
FORD WINDSTAR (2001 - 2003)
LINCOLN LS (2002 - 2003)
MERCRUISER All Models (1996 - 2007)

Part#'s from several manufacures:

Mercruiser / Quicksilver #1F2Z9F715AA, #862998
MOTORCRAFT CX1766
Standard Motor Products #AC423
Delphi #CV10103
ACDelco#217-3217
BWD #50558

The BWD 50558 does not work correctly on the Mercruiser apps and FWIW it is made in Mexico, I will test this again to verify on another app to confirm 100 %. This Ford style IAC thru Merc is used on a lot of their apps across the board..

Do NOT punch holes into your oil filters to help drain them. - where do you think that metal of the hole you punched it goes ? You are breaking small metal fragments to make a hole - it drains back down into the oil system with the oil that is draining from the oil filter.

A little story OEM new boat with Mercruiser years ago - Not mine but story was new boat in for the after engine breakin 20 hour service - motor oil & filter change - tech punches hole in the oil filter to drain to prevent mess while changing. Tech completes service - boat owner takes boat out 6 hours of engine run time afterwards - engine failure - Merc warranty - sorry warranty is void - why - because we found metal oil filter pieces in the oil system. How did that happen - Who punched the oil filter to help drain it before the change ? - end of story.

Good luck with that - makes sense now why not to punch a hole in your oil filter.

Unscrew it slightly and gravity will help drain it beforehand . Tip for everyone.