What was the engine originally?? 502Mag or HP500?? Did they upgrade the oil cooler??

lake st.clair,,,where i boat,,,
i was running high temps 260ish,,,machine shop didnt seem to think it was too hot,
but had to pull motors to address water pump changes, i updated oil coolers with big
CPH-700 Thermostatically Controlled Cooler 3 inch bundle,from mr cool
now motors run 200 -230

Any idea how much a high volume oil pump may raise oil temps , compared to the std oil pump??
I have a stock 1998 415hp 502mpi just with Eddie Marine exhaust and some advanced timing at WOT to 36 deg.

I like simpler the better. I am trying to run without all the remote filter setup, oil cooler, hoses, which adds weight and takes up room, and potential leak spots. Often hearing these stock motors dont need the high volume pump, just the standard unit.

I'm hoping that with doing a couple other things like lower the timing a couple degrees, and checking for lean AFR, that i can run without a cooler/remote filter setup.
Oil temps running a little high, 280F cruising just under wot.
I like the oil a little hot to keep the oil as dry as possible. Would like around 250max running hard, over 200 cruising easy.

what engine(s) are you running? Overwhelming response are indicating oil cooler - I’m going to purchase just need to find correct one for me..

502 mag. Didn’t upgrade oil cooler

I am having the same issue with hot oil, I have cleaned coolers and replaced water pump. I too am starting to believe it is the actual size of the cooler. I run the same 20-50 oil but if i run with or without an oil thermostat installed, my temps are climbing to 280 on a 4000 rpm run for 15 mins. Im not trying to hyjack your tread but have been battling this since i got the boat last year. No thermostat in engine with a cross over and never see my water temp gauge move. Took a test ride today in 45* water and after 30 mins still saw 280 on the gauge. Im going to measure my oil cooler tomorrow. What size did you end up going with? Never had any problem with the engine but still concerning when your oil temps rocket, water pressure is considerable low at 5 psi while cruising and then not seeing any water temp. Hard to really tell condition of what is happening. Im assuming the low water pressure has to due with the fact of not running a thermostat with the crossover, but worried about adding restrictors in housing to boost pressure and then have my oil get even hotter with less flow of water.

What engine and specs? Custom build? Sounds like you might be bypassing the cooler. Do you have the marine heavy bypass valve in you oil filter pad, is it plugged or the light automotive bypass?

do these and be done with it, if you get it wrong it's only your motor.
https://www.hardin-marine.com/p-1097...ing-mount.aspx
https://www.hardin-marine.com/p-1097...rmostatic.aspx

Its a Mark IV Dart 555 block, Brodix Aluminum heads, brodix hvh intake and quick fuel 1000 carb. All raw water cooled. Was told makes around 750 HP but have no actually specs on that. Where would that be ? Inside the filter mount? So you think it’s not pumping though the cooler at all? Compared to what GLENAMY just posted my cooler is not nearly that big. I have to write 10 post before i can submit a photo.

You need minimum 3x18" CPH-550, CPH-700 if you want thermostat. Russ usually gives an OSO discount.
https://www.mrcool.us/coolers/hi-per...e-coolers.html