Optimum oil temperature

[CycleSi]

I have an R300K which I track a fair bit (10/12 times a year) and wondered what the optimum oil temp is on the road and also, more importantly, on track days?

[Titanium7]

Don't see the R300 here but I am sure it would be in line with all the other R series.  Best bit of advice is don't give it the beans until the oil is at least above 50c

 

Advice from the original engine builder for the R500 and R400 was minimum 50c maximum 100c

 

follow the customer support link and then the engine data pages

Here

 

[Slipper man]

The answers above are correct, so long as you have the Caterham dry sump system. These temperatures  are for the oil in the bulk oil tank, and I recall Jez Coates saying when my car was new that if the gauge read 100 deg, the oil at the bearings would be c. 130 deg.

If you don't have dry sump, the acceptable readings would be higher, but I am afraid I don't know how much.

[Slipper man]

Looking at the data sheet for my engine, it is interesting that it says 97RON fuel. At the time, they said it was mapped for 95RON fuel.

[Garth]

I use Royal Purple oil (as recommended by the HWR who rebuilt my Sigma!). Royal Purple say their oil (10W-40) should operate between 82 and 104 degC to give optimum protection. What I have not yet got a good handle on is how the oil temperature will vary in different parts of the engine - I measure my oil temp at the oil filter and it does get above the 104 when pushing hard on track days (am amazed how quickly the temp drops when dropping the revs a bit!), but would like to understand this better!?

[7 wonders of the world]

There are many places to measure the oil temp most places are chosen for concenience rather than understand the system and chosing a point that will give an accurate and useable reading.

Compare with a cooling system where the coolant temp is measured pretty much at the point where the coolant at its hotest and leaves the cylinder head (or engine outlet) so you are seeing the mximum temp (or as near as) if, however you measured the coolant at the bottom of the rad you would see a much lower temp.

Many systems measure the oil temp in the DS tank which is fine for giving a good guide to when the oil is warming up and therefore when you can give it full beans, however the temp registered here will be well shy of the peak oil temp in the engine, so in  DS system I would look to mesure in the sump trough this will give the nearest peak reading as it is where the engine oil is at hottest measureable point ie after it's fulfilled its lubricating and cooling role (remeber oil is responsible for at least 60% of the engine cooling and it the only thing to come into contact with the hotest parts of the engine, bearings, cylinder walls piston crown etc).

The further down the oil system you measure the lower and more inaccurate the temp you with see, so after scavange it will fall, likewise and naturally after the oil cooler too it will drop, as it returns to the tank it will be deairated and swirled around the tank so again cooled further meaning the tank temp if used as a max will be 30-40 degrees below the true max.

Backing off the revs will drop the engine power - less power equates to less heat being transfered to the oil its as simply as that.