What sort of oil temperature is acceptable for a bike engine? At the test day today we were running around 85-90degC when hammering it going up to 100 when coming in after a few hot laps. Is that anything to worry about?

depends on the spec of your oil

i dont know anything about bike engines (yeah im building a busa and should find out) but 85 seems somewhat low

i run an r1 powered mk
using shell vsx 10w40
and my oil temp when driving is mid 70s
then in traffic can go up to 86 or so
as long as the oil is above 50 you can hoss it

100c is fine

MY 4age says its between 100-120 bepending on how much I am ragging it. That is with the sender right on the side of the engine by the cooler outlet and under the manifold.

I hope that is ok!!

When the oil temp goes up and the oil pressure goes down at the same time, you are looking the oil.
Your temps seem ok but an oil cooler and thermostat would help.
Oil coolers loose a third of there cooling efficiency quite quickly so fit a larger tha expected one.

Cold oil kills a lot more engines that hot oil.
Ideally the oil should be above 85 to 90c --- as a general guide as long as the oil temp is within 10 degrees of the water temperature all is well.

If fitting an oil cooler always fit an oil thermostat.

The R1 (04-06) manual lists running oil temp as 100'c.

Your's sounds normal to me. Don't worry about it unless you see big differences between oil/water temp or oil temps up above 110. As Triton says cold oil is the killer... or rather ragging it before the oils warmed up.

adrian

I don't have any water Oil cooled engine. Sounds like I don't have any problems.

Cheers for the advice guys!

Oil can normally take temps 20 % higher than water temps without problems. 250 F is normally seen in aircooled aircraft engines in climb.

my blade engine was hitting 125 at cadwell recently. it was a hot day.
looking into fitting a cooler now