oil cooling

[martinlaw]

I have a GTR with a 535bhp AP engine with standard oil cooler and Pacet fan to assist the oil cooling.

Will this be enough to keep the oil temps within reason on a track day?

Reason I ask this is I also have a Sport with same size oil cooler and fan but with only 400bhp and after 6 or 7 laps around Outon Park I have to complete a cooling down lap as the oil temp goes up to 115C.

i know the cooling efficiency is better in a GTR, but how much better?

Any advice would be appreciated.

Cheers,
Martin.

[eliot]

If you have a good quality fully synthetic oil (silkolene pro-r for example) AND the temperature stays at 115c - then I wouldn't worry too much. But if continues climbing over 120 then you need to look at more cooling. Non synthetics wont tolerate these high temperatures though.

My turbo chevy runing said oil does this when pressing on - i'm running a 24 row cooler on the front. (Not in an ultima mind you)

[Steve_D]

Will have a look tonight but from memory temps that high using synth are actually where the best power is produced. You want to aim for an oil temp higher than water temp.

Later
Steve

[Steve_D]

In a book by David Vizard he is saying that mineral oils are OK to a max 120 degrees C and that power is increased at these higher temps but that is mainly because the oil is thinner. Synthetics are a more constant viscosity across temperature so there is no significant gain to be had by running them hot. Synthetics are good for 150+ degrees C.
As well as lubrication the oil is acting as a coolant. The ideal temperature hear for a synthetic is 76-88 degrees C.

Steve

[martinlaw]

Thanks for the advice Steve.

I have been advised to run a good quality mineral oil in the American Speed engine so i will set the oil temp warning light to 119 degrees and the fan to kick in at 115 degrees.

Never had any problems with high water temps, it is just the oil temp that seem to go up although i do use a fully syn. racing oil in the Sport so if the temp can go up to 150 degrees, I dont think i actually have a problem.

Cheers,
Martin.