higer oil temp after rebuild, bypass??
 

Have a friend with twin 500EFIs. One was rebuild top to bottom this past winter, the other got a top end fresh. Now oil temp is 50+ degrees different, not off the charts but different. He is running in real cold water (Great Lakes) 52 degrees. Oil temps on hot engine runs 190 to 230 and climbing when running hard. Cool engine 150 to 180 running hard. Water temp is exactly the same, exactly. He is concerned that later in the year, doing runs on warming water will give him serious issues with hot oil. I don't want to debate how hot oil can get, just want these engines to match as they used to.

A while back I read something on here about a bypass that has to be reinstalled on marine engines where the engine block filter housing would be? I searched but can not find it. Can someone explain what this is? Is there a chance the builder left it out? Can it be installed with engine in the boat or is it internal?

Thanks

when the rebuild wes done was the origional bypass used and what kind of oil temp did he see before the rebuild?i would suggest checking the grounds at the dash and replacing the oil temp sending unit ,the oil temp might not be as hot as the gage sais it is.

That is good info, thank you.

Still wondering what a builder may have changed or left out however. The engine was rebuilt as stock, to match the other one.

Borgi don't wan to beat a dead horse but i will still ask :D if i remove the 11lb valve and install the 30lb valve do i have to plug the inboard hole thanks rod

Are you noticing a difference in oil pressures between the two motors? I am curious about the pressures at idle, cruise, and WOT when the temperatures are different.

oil pressure is the same at all rpms/ temps

If pressures are exactly the same I'd think he has an indication issue.