Oil Question

[sprocketmensch]

Alright so I'd like to hear everyone's opinion on what oil they are using and what they are seeing on wear. How often do you change it, how dirty is it, etc. We can't change the engine build but we can change what we put in. Also GSXR v Kawi, any differences in oil?
Doug

[ghickman]

Using Mobil 1 10-40 motorcycle oil. Gets changed every race weekend. Zero engine failures since 2014. I run the piss out of my engines they routinely see 13,300 and sometimes more.

Never seen any appreciable wear on bearings or valve train.

[Jon Jeffords]

I use Mobil 1 10W-40 4T Motorcycle Racing Oil.

George Dean told me to change the oil filter every weekend, and the oil every other weekend. He recommended the Redline 40 weight "full race" oil.

I wouldn't consider the oil's visual appearance to be an acceptance criteria, as our oil change intervals for race applications is too short to get much discoloration. Besides, you want an engine oil to eventually appear dirty, as this indicates the detergent additive is doing its job keeping the piston and ring grooves clean. I would be very concerned if I drained the oil out of my street car at 7500 miles and it came out of the pan a clear golden honey color!

[sprocketmensch]

I have been wondering if there is an advantage to running a lighter oil. Our oil is not just around the engine moving parts but also flows throughout the tranny. Would moving a lighter oil provide less resistance at 13,000 rpm? Or this just a recipe for not enough coverage and engine failure? Anyone ever dyno'ed an engine with different oil weights?

[ghickman]

I have been wondering if there is an advantage to running a lighter oil. Our oil is not just around the engine moving parts but also flows throughout the tranny. Would moving a lighter oil provide less resistance at 13,000 rpm? Or this just a recipe for not enough coverage and engine failure? Anyone ever dyno'ed an engine with different oil weights?

If you've got good O/P to begin with then go down in weight. Dyno numbers say it is worth it.

I just ran zero wt. for the first time, so far so good.

[TDI PILOT]

What would be considered good oil pressure?

I am seeing no less than 25 anytime during a race, but when the engine is idling with HOT oil its around 5 psi.

[ghickman]

What would be considered good oil pressure?

I am seeing no less than 25 anytime during a race, but when the engine is idling with HOT oil its around 5 psi.

Anything below 40 psi for me at WOT is not good. I normally see 65 psi and above on warm engine at WOT. Anything not at WOT I ignore.

My engine builder is very good at getting clearances dialed, this is on a Suzuki with wet sump pan.

[sprocketmensch]

Gary,
Can you share what advantage you are seeing in HP or in top speed?

[David Locke]

What would be considered good oil pressure?

I am seeing no less than 25 anytime during a race, but when the engine is idling with HOT oil its around 5 psi.

It really depends on your bearing clearance. On a "tight" Suzuki, you should see no less than 50 psi at wide open throttle at 12,000 rpm. On a Suzuki with larger bearing clearance, my engine builder says I should see at least 40 psi at wide open throttle above 10,000 rpm. Under heavy braking at the end of a straight, it's good if your oil pressure doesn't drop below 25 psi, because the engine spins up pretty quickly in second gear when you get back on the throttle, and the oil pressure doesn't recover instantly.

[John Mosteller]

A ow20,0w30,w40, 0w50 etc are not 0w at operating temps.A 0w20 is a 20w oil , a 0w30 is a 30w oil,a 0w40 is a 40w oil and a 0w50 is a 50w oil. They have a 0w viscosity when cold.Once the oil gets above around 130 deg there is no difference. A 0w40 hot will have the same viscosity as the 40w George is recommending so it will be the same on the transmission. If you don't warm your oil up before going out and plan on hammering it a 0w would be better for the motor. If you are going to warm the oil first I would side with George and go with a good 40w racing oil.