I know there are some threads on here about oil temp and I think I read through a lot of them. I just want to better understand that my previous boat had stock 502MPI Mags and the oil temp would barely move the gauge and never go above 140 even running it hard, the water temp would sit at 160ish. Now I have a new boat with 540s, AFR heads, and harden oil coolers and no circ pump. I only have run it a few times but the oil temp is 190 cruise and pushes to 220 when I run wot, but the water temp barely moves of the bottom of the gauge. Completely opposite of what I was use too. Any insight would be appreciated, I think it is working correctly but would love input. Thank you in advance.

Sounds like your old motors had water thermostats, and no oil thermostats. And your new motors have no water thermostats, and oil thermostats.

I like the new setup you have better.

+1

i have a dart540 with 345dart heads dart single plane intake . my water temp stay at 150 my oil temp i have to hook up so i can help you there . i frist ran the motor it was running to rich and the water temp was at a 100. i put a im a/f box on it running 98jets at 11.2 lower the jet to 86 pri. 88 sec. af now 12.7 up to 3000rpm and 12.5 wot now the water temp is 150 i hope that help you outand the timing is 36

+2
Also your old setup could have been taking the temp after the cooler and now it might be before cooler.

My oil after the cooler I might see 160*F.

+3 .....IMO your temps are perfect.

I'd be sure to check both banks if you havent with the Wideband. If you gained 50* of water temp from jetting, I'd be worried about how hot those pistons are getting, and def add oil temp gauges.

A buddy of mine built himself a blower motor, ran it lean, oil temps were 300* before it let a rod go thru the side of the oil pan and snapped the cam in half...

Thank you everyone, makes me feel better for sure. I will take a look to see if i can tell where the sensor is and it may be before the cooler like you said, which is great. The motors def run rich, as I noticed black soot on the transom after running the first 2-3 hours. They have 500 EFI intakes with throttle body work to feed the 540s done by CK Motorsports in MI, first time I ran 93, he says do not and run 87 and soot should go away. We will see when summer finally comes again here...

No way your oil temps were correct in the old engines/boat. The oil temp sensors were obviously located in the wrong place. If they were running that cold, then you would have had milkshake oil from condensation.

Where are the oil temps being taken on the new engines???? The current oil temps look very good and are exactly where you want them.

ive a friend that has the same issues with his oil temp and where to instal the sender for temp to give you a true reading or a proper reading of what is actually happening, boiling oil is not a good thing