HOTROD2

What should the oil temp be at hard running in a large boat? Or what is your oil temp so I can get an idea if mine is to high or to low??? It currantly starts at around 220 and the goes up to 320 at wot... this seems to high to me???

BadDog

Where are you measuring your temps?
Here are my temps with a large cooler measured after the cooler at the oil filter pad.
Stock 502 before blower add on, 210 at 3200 rpm and 225 at WOT with Mobil 1.
502 with blower 225 at 3200 and 245 at WOT.

HOTROD2

The temp senders are next to the factory filter mounts on the left side of the block in the filter adapters. (stock Merc location)

maverick1

Even Mobil "1" tech line will tell you that over 260 deg. is pushing the safety envelope.

How long are you "standing" on that throttle --- 1 mile, 3 miles, 10 miles????


I run mobil "1" and a 502 EFI and will cruise around 220 deg., with a mile or two @ WOT I will approach 250, and I guess it would keep climbing - I haven't chosen to find out.

My guess is you're running too small an oil cooler.

MAV

P.S. My Gaffrig oil temp guage is tapped in at the oil filter.

MACDAD260

My 502 with a 16x2" cooler (12" of actual cooling) with the sending unit at the remote filter, before the cooler, runs about 210-220 at 3500 rpm cruise. At 4000 rpm about 230 and about 10* more for every 500 rpm above that. Someday I want to put a sender in the block, after the cooler, just to see how much difference the cooler makes.

blue thunder

Mine run about 220 at 3200, 230 at 3500 and will stay that way all day long. At WOT though they never seem to plateau. At 260 I pull back. That usually takes about 2 minutes at WOT and starting with a fully warm engine (230). Temps usually fall right back to under 230 in about a minute.

Not happy my temps keep rising like that. I was trying to run dino oil this year, but I think I cooked it in one of the engines yesterday after I let it get to about 280. Oil pressure did not rebound properly in one engine after cooling. Still had the 10psi per 1000rpm, but not the same as before my romp. I will be changing oil this weekend and hoping for the best.

What I want is engines that will run about 210 at 3200, and never exceed 250 no matter what I do. Definately thinking I need bigger oil coolers. If you have not changed the oil in the engine that reached 320F, I would do so before running anymore. I measure in the oil filter adapter as well and consider oil that reached 320F pretty well shot.

BT

MACDAD260

Has anybody ever ran two senders so you could measure temp before and after the cooler? For you guys that are running senders after the cooler and still seeing 250* I wonder what it is after running through the engine?

GregP

I know my oil runs a little cool, but it is a lot lower than you guys. At 4200 RPM cruise it will just get up to 200*. At 3500-3800 cruise it will stay about 180*. I've run at 4200 for at least 30 minutes and the temp stays stable. I'm running the stock Merc bellhousing cooler and have the oil temp sender in the block at the filter pad also.

-Greg

Scott

When someone asks why I am wasting my money with synthetic the above is the answer they get. It is that one time your oil temp gets so high that the dino oil breaks down and then
To me it's cheap insurance.
I really need to order some Temp gauges I have senders wired from Merc (HP500's) at the pad but the manufacture did not but in the gauges How stupid is that

bobby daniels

Boy I 've worked alot with this and DOUG is right this is why to run Syn, oil ,,,,,regular will coke up at 260 and it is hard on mobile , you can and have to know is the oil temp being read after the cooler or before ,,,,I use both to tell me if the engine is losing a bearing ect. when you measure out of the motor ,the main thing is the oil going back in the bearings (motor) !!!!!!amsoil,redline ,royal purple will stand 320 (or higher)due to the poly base their made of ,,,Mobile ect are great and will far exceed conv. up to 300 for short short times and 2600 for a good while with no problems

it needs to stay 212 or hotter or you have condensation problems sory GREG add a thermo .to your either a high dollar Eickert or call 411 for CV products in High Point N.C. 919 or 704
aera code they make them for Keith anyway

Or get a good cheap on from summit PERMA_COOL