buddy just purchased an 05 38 slingshot w illmor 550's n arnesons didnt get any water coming into the strainers unless engines were 1500 rpms or higher. my question is regarding the raw water pumps on the v-10's. do they use the same impellers as merc ? once run dry and over heated are they shot ? any assistence would be helpful.

thanks Bernie 732-539-5882

They use a Latham pump, don't know if the impeller is the same.

Yes they use the same impellers as merc. The water pumps on the Ilmors were a problem on some applications so Ilmor came out with a new design on their pumps around 2008/9. It resolved the issue as far as I know. The older style pumps worked on some applications but just didn't on others, which prompted the design change.

If you are having issues then I suggest your buddy spring for the new style pumps. They are not cheap though.

Mine is a late 08 unit with the newer pump.

Ilmor water pumps had an issue with not pumping enough water at idle and as Marginmn correctly says there was a design change to a new pump.

The new pump is an all steel unit and looks a lot like a hardin marine part (good!) and uses a standard merc impeller. (also good!)

The new unit has quite a bit of "crush" to the impeller vanes and I have not had an impeller last more than a season I took a look at the last one removed a few weeks ago from sitting 6 months and indeed one of the vanes was cracked already so I can say the new pump supplies plenty of water at idle but its design necessitates an annual change at min.


Have your buddy call paul ray, at Ilmor and get the new parts.

Uncle Dave

thanks all...MM was great speaking with you today. its turns out the bodies are KE and the std merc impellers went in with ease and all is good