hotjava66

Curious what is normal for oil temp. My engines are pretty much stock 502's, have crossovers and build very little water temp but can build oil temp in the 260-270 range if I run them hard. Is this excessive?

BenPerfected

Not if this is for short periods like WOT. What is your oil temp at a steady fast cruise?

stevesxm

well... not sure i agree w/ that. certainly if i saw 270 once in a while i would think its surviveable but if you are saying that you can run cold water temps and oil temps that high without ever stabilizing at some temp then i would suggest that thats not good for the motor at all. i would think that you would want to shoot for at least 165 water temp and to be able to run the boat at hard as you want for as long as you want and have the oil temp stable at 240 or 250. if the oil temp never gets stable ( and the motor isn't blowing up) then your cooler is too small. but while i will certainly get some grief here for saying this, i maintain that runing excessively cold water temps is a bad idea across the board and has no upside at all unless you are running massive boost or racing compression ratios.

hotjava66

At a steady fast cruise 3000-3300 RPM 200-220, long idle in no wake it drops to 140-150, 4000-4500RPM puts it up around 240-250 WOT it creeps up from there. Water temps never go past 130. Was thinking about adding thermostat setup to the crossover but with the oil temps spiking like that im hesitant. I am running synthetic (Amsoil) so hopefully it will be ok. Read an old thread about 502's having lots of restrictions in the oil system but I dont want to start a project now that the season is started. This may sound dumb but where is the oil cooler on these, is it a big deal to change out maybe I need to do that.

stevesxm

on mine , which are year 2000 mpi's , it is vertical on the front of the motor next to the filter adapter and will have a big water line coming in and out of both ends and the oil lines from the adapter running into the sides. and for the record, with box stock hardware, i run 170 water, 230 to 245 oil at WOT for as long as it takes to get where ever i am going. with the stock tstat and cooler the water temps come right up and after a bit the oil temp gets to 200 and will move between the 230 and 245 as a function of load. i will correct myself in one thing tho, i said that that is with all stock hardware and plumbing which is true. however i did make some changes to make sure the engine compartment is well ventilated and exchanges air such that even at WOT it doesn't get much hotter that ambient. i can't tell you how much that alone increased the performance and stabilized the engine temps. i had a race car that one day for apparently no reason started running the oil temps at 300 ... from the day bef when they where perfect. long story short, it turned out to be the simple fact that we had lowered the front spoiler down an extra 1/2 inch and shut off the air flow under the car. that flow was using the pan itself as an oil cooler. took the extra 1/2 inch off and everything went back to normal... i think the same is true in a lot of boat engine compartments where there isn't enough air exchange to allow the heat soak to dissipate. thats what i fixed on mine with great results.

BenPerfected

I think you will be fine with the oil you are using. Maybe this winter you could look to change some things to drop your oil temps above 4000 RPM.

Ted G

iTrader: (1)

On your engines it should be mounted at the rear above the bellhousing, just follow the lines from your oil filter adapter, one will go to it. It has 2 high pressure oil hoses and 2 water lines to it. You could also pull it, open the end caps and see if it has crust built up in there. If it does, a dip in CLR or muriatic acid will make a huge difference.

blue thunder

A good thing to do initially is validate the tune is correct. Lean or too much timing at elevated rpm will make the oil temps go up quick. As long as the tune is good, it is most likely a matter of bearing clearances are a little tight. Keep your coolant temps low as possible, keep the engine room cool, run syn oil and when you see 260-270 pull back.

hotjava66

engines are low hours, maybe 40-50, could be tight yet. havent checked the timing, carbs are prob a little rich cause my transom is getting sooty.

kneeslider74

If you have an oil cooler a good rule of thumb is 25 to 40 degrees hotter than water temp. You need to get an actual reading off the oil pan to prevent chasing your tail. I had similar deal with diesel motor and finally laser temped the pan and led me to the sender, just like that. I have never seen a proper running motor that isn't full blown racer with oil over 230.
As far as amsoil handling the temps, it may do just fine, but the other components may not do as good, ie. head gaskets, intake gaskets, and so on.