a crossover bolts on to replace the circulating water pump,most of the time when the circulating water pump is removed so is the water thermostat.this is done to remove more heat[usually on supercharged engines].

Oohhhhh ok. Yes I have a cross over tube. No thermostat. With the intake manifold for the blower there is no place to have w thermostat anyway. I will be changing all the water plumbing in the next couple months as it is not correctly hooked up right now. Saving some money so I can get a sea strainer and transom pick up for the super chiller. Not enough water pressure going thru the engine as of right now also I have water running thru the chiller at idle. I want to go back to a single stage sea water pump and feed just the engine from that

I could be wrong, but I believe the purpose of an oil thermostat is to heat up the oil to operating temperatures faster when starting up.....through no wake zones etc. If your oil is only running at 140 you have too much oil cooler for your set up. Oil temperature should be at least the boiling temperature of water, 212 degrees. 230-240 is by no means too hot.

My issue is I am very nice to my motor, it stays at 3500 rpm 98% of the time. But when I do open it up it does heat up to about 210-220. That's after about 40 seconds to a minute. I never stay on it. I think it would keep climbing if I stayed in it (I chicken out around 85 mph). I think without the cooler I wouldnt be able to hold it open for even that long. If it doesn't fix the problem I guess it should help heat up the oil during idle....the needle never moves while idling

Most Good Dino based oils will safely and reliably hand temps to 275-280 without much oxidation. If you put a temp gauge in the pan of your old BBC in your dually it would scare the **** out of you what temp it runs while your pulling something!

My 525efi would rise to 190, then open and settle back down to about 160.

my procharged setup ran really cold oil temps as well, used a canton even at 3500 cruise still maintained just over 200 oil temp, water was always 125-140

Well that's better then 140. I'll let you guys know the outcome. Hopefully put it on this weekend but won't use the boat till the weekend after unfortunately

You can install a bypass with a ball valve and route the water around the oil cooler ...I have done that before and you can adjust oil temp accordingly...

For what it is worth, Eddie Young (Young Performance ) set mine up with a 190 degree oil thermostat. It also has a large oil cooler and runs in the Greater Lakes. Eddie wanted to be sure that oil warmed up ok.

Padraig