What Race Oil do you trust?

[curtis reed]

Originally Posted by Bobby Fazio

Reviving this thread to ask if anyone has given thought to Viscosity Index? As I understand it, the higher the VI number, the less the oil changes with temperature. In trying to be as consistent as possible in our classes- cold morning runs vs a hot laps, would it make the most sense to run oil with a high VI? I've noticed Royal Purple, Eneos, and Driven have high VI numbers.

I would also extend this question to ATF and Differential as well.

Do you monitor oil temperature? Use an oil heater? If you don't know what temp you are racing at it's hard to center on whether the oil is what is could be causing an ET difference.

[Bobby Fazio]

Originally Posted by curtis reed

Do you monitor oil temperature? Use an oil heater? If you don't know what temp you are racing at it's hard to center on whether the oil is what is could be causing an ET difference.

Just Trans temp but plan on monitoring both atf and oil temp next year.

[curtis reed]

Originally Posted by Bobby Fazio

Just Trans temp but plan on monitoring both atf and oil temp next year.

Good call. It's surprising how hard it is to keep enough heat in the oil.

[427FE]

Originally Posted by curtis reed

Good call. It's surprising how hard it is to keep enough heat in the oil.

How much heat do you want in the oil?

[SSDiv6]

Originally Posted by 427FE

How much heat do you want in the oil?

You want around 220 degrees F minimum to get rid of the water vapors and burn any deposits to prevent sludge. Dinosaur oil, 220 degrees F to 250 degrees F. Synthetic oil 230 degrees F to 280 degrees F.

[Jim Caughlin]

Originally Posted by SSDiv6

You want around 220 degrees F minimum to get rid of the water vapors and burn any deposits to prevent sludge. Dinosaur oil, 220 degrees F to 250 degrees F. Synthetic oil 230 degrees F to 280 degrees F.

Really hard to get the kind of temps needed into oil in the real world, even if you have an oil pan or oil tank heater on your car, you'll be surprised how quickly it cools down just driving to the lanes. Anything short of hot lapping and your oil is probably too cold. Same goes for trans and rearend.
Interesting sidenote, occasionally on the dyno, you accidentally get the oil too hot prior to a pull, counterintuitively the best thing you can do is fire the motor and it instantly sucks the heat out of the oil, it will drop 20 degrees if not more. Bringing up oil temp with the heater while the motor is turned off is easy, very hard to increase oil temp while the motor is running. Monitoring oil temp on a dyno definitely proves that cold oil sucks a lot of HP.

[SSDiv6]

Originally Posted by Jim Caughlin

Really hard to get the kind of temps needed into oil in the real world, even if you have an oil pan or oil tank heater on your car, you'll be surprised how quickly it cools down just driving to the lanes. Anything short of hot lapping and your oil is probably too cold. Same goes for trans and rearend.
Interesting sidenote, occasionally on the dyno, you accidentally get the oil too hot prior to a pull, counterintuitively the best thing you can do is fire the motor and it instantly sucks the heat out of the oil, it will drop 20 degrees if not more. Bringing up oil temp with the heater while the motor is turned off is easy, very hard to increase oil temp while the motor is running. Monitoring oil temp on a dyno definitely proves that cold oil sucks a lot of HP.

Jim,

Right on the money on an engine loosing power with cold oil.

How many times have you removed the oil cap or valve covers and seen the accumulation of moisture before you make your first run of the day?

I believe the best approach and practice would be to heat up the oil or run the engine until you go above 230 degrees F to get rid of the water vapor and burn the deposits prior to the first run of the day. A heater would be the best way and economical since you would not be running the engine and wasting race fuel.

[curtis reed]

Originally Posted by 427FE

How much heat do you want in the oil?

SSDiv6 gave a good answer. In my experience it is really hard to get/keep that much heat in mine unless I am making laps within 20 minutes. The double races I hit and making late rounds of both I will see 250°. I am on alcohol though.



I try my best to never hit the water with less than 150° oil temp though.

[Bobby Fazio]

Originally Posted by curtis reed

Good call. It's surprising how hard it is to keep enough heat in the oil.

Does this differ with steel vs aluminum pans?

[SSDiv6]

Originally Posted by Bobby Fazio

Does this differ with steel vs aluminum pans?

Yes, Aluminum pan dissipates the heat off the engine oil faster than a steel oil pan. The steel oil pan will keep the heat for a longer period.