Engine oil temperature

[Draven]

oil temp should be somewhere in the vicinity of water temp ... as stated, 80-100c is a vague sort of idea.

[Negative Boost]

I would locate it after the cooler so you are reading the actual oil temp the motor is receiving.

I was thinking the same thing, is this correct? Or should the temp be taken from the oil in the sump?

[off-road]

You are better off knowing if the oil being pumped into the motor is too hot or cold.
In high performance applications where oil temps are approaching the point of oil break down you could always use teletemp strips that record highest temperature. Stick some on the sump and on the hot side of the cooler if you can.

[YLD-16L]

I was asking myself this exact same question a few weeks ago and a lot of searching on the net brought up very little info on the subject.

The little info I did find indicated you want your oil temp to be at/above 75-80 degrees celcius during normal operation (as has already been mentioned).

As has also been mentioned the general consensus appeared to be that for synthetics and semi-synths above 120 deg celcius is not a good zone to be in but they will cope with that if you happen to end up there i.e. breakdown will be minimal.

FWIW Norbie I run a basic oil cooler setup with a permacool thermostat and it's been fine down to about 0 degrees celcius so far (coldest temp I have driven it at yet) it's held 75-78 deg C on the gauge during normal commutes and hwy driving, which is fine.

On the track the highest temp the oil has seen is about 104 deg C.

Sounds like a thermostat should solve your issues and be much less hassle than covering/uncovering the core all the time.

[jezza323]

Keith (MonkeyMagic) runs a cooler out the front of his sprinter - without a thermostat he resorted to a removable metal plate in front of it for street use and at QR he removed plate.

why would you bother when you could do it properly with a thermostat

[Hodgo]

While on similar subject, while the reccomended engine oil temp has been mentioned.
Can someone please tell me the the same for a manual gearbox/diff oil.

The only info i can find is on autos and they appear to run much higher temps

FYI I have a fwd type gearbox with clutch LSD and i have been having overheating issues so I am after a more definitive answer as to what the themp should be.

Ta, T

[abently]

I was thinking the same thing, is this correct? Or should the temp be taken from the oil in the sump?

I would want to be knowing the MAX Temperature the Oil is reaching, which means the Oil Temperature before it gets cooled.

It is the MAX Temperature you need to see to know whether or not it is getting close to breaking down. And if it is, then you know you need to upgrade the Cooler, or make a Shroud for the original.

[chris davey]

why would you bother when you could do it properly with a thermostat

How often do you race your car? How hard is it to undo 2 bolts? I would just do that personally

[ed]

why would you bother when you could do it properly with a thermostat

properly? if he was doing it properly hed use race tape... show me what nascar, jgtc, btcc etc all use

thermostat is a huge flow restriction, and implies the cooler is bypass not full flow. Im running -12 lines around the full flow cooler, show me a thermostat that will keep up with that if i switch to a bypass setup

[DX20VT]

I too run a full flow cooler with no thermostat.
I'd rather not have any un necessary restriction in oil flow,

as not only does it reduce the oil getting to the engine,
but the pump will drag more hp off the engine.

[abently]

I too run a full flow cooler with no thermostat.
I'd rather not have any un necessary restriction in oil flow,

as not only does it reduce the oil getting to the engine,
but the pump will drag more hp off the engine.

Hahhahah, more drag on Oil Pump / no restriction on Oil Flow ?

The Oil Cooler alone will have a readable restriction on Oil Flow.

Fact remains, Oil too Cold is not good for the Engine and if the Oil Cooler is in an awkward position, I'ld fit a thermostat.

[Norbie]

My understanding is the thermostat simply short-circuits the cooler, I don't see how this could present a restriction to flow?

[YLD-16L]

My understanding is the thermostat simply short-circuits the cooler, I don't see how this could present a restriction to flow?

You're correct, the thermostats designed to be used on a full flow system would have a negligable restriction, if any on oil flow. The ports/passage on the Mocal/Permacool thermostats are just under 1", they are designed for -8 or 1/2" fittings/lines.

Ed's system using -12 would obviously suffer restriction at the point of a thermostat due to having to pass through a smaller passage but most setups on street/track cars not dedicated track cars use 1/2" or -8 lines and fittings so it presents no restriction at all.

I drew a dodgy pic below to illustrate how these thermostats function and as you can see the only "disruption" to oil flow through the passage is the posts that locate the thermostat and they are quite thin and as I mentioned earlier the passages are larger than the lines anyway.


Shot at 2007-07-03

Mine holds 80+ psi through to 8000+rpm so I have not noted any restricitons with my setup as yet and given my car is a street car that goes to the track I think the thermostat is a handy item to have. I wasn't keen on having no thermostat given I have to drive in sub-zero temps through winter and I wasn't keen on covers etc.