LLY: Oil temps

[Cougar281]

What's the max "Safe" Engine oil temp? For my trip from St Louis to New York, my truck ran between 210 and 230 (oil temp on the hot side) for the most part, but spiked up to around 250 a few times and almost 260 once on a long grade in PA on I-80.

Other than that, the truck preformed well with a 220HP tune loaded; had to back it down to 160 because I didn't like how quickly EGT's rose in 5th gear on the grades forcing me to downshift to avoid melting the turbo or pistons (Yes, I have a full LBZ intake from airbox to turbo)...

 

[Fingers]

Depends on Dino or Synth. Most Synthetics will go to just under 300* before any issues. Dinos like to be below 280*. I assume that is pan temperature.

 

[Cougar281]

That temp was at the "hot" port on the oil filter adapter, and I'm running Mobil 1 Turbo Diesel Truck/Delvac 1. I was referring more to the safety of the motor though; I've read that oil temp is a good indicator of how hard the motor's working, and oil getting too hot could be a factor in cracking pistons.

 

[Fingers]

The oil temps do respond to engine load, but I don't know that you can use the temp alone as an indication of working the engine too hard. Just like you can't use ECTs as an indication. Too many factors. Flow rate, cooling capacity, .........

If the fluids are getting hot, you need to either back off, or add additional cooling capacity for the fluid. In the case of the engine oil, if it is climbing unchecked, yea, you're working the motor harder than it can maintain. Or at least harder than the cooling system can maintain.

The bigger problem is if your fluids are NOT getting hot, yet the parts they are servicing are.

But, what do I know.

 

[Killerbee]

A number of folks, including myself and fingers, have logged well over 300 F.

If that was your hot side, that's not too bad. But I think you have a good point, but thermal cycling being a bigger stress than absolute temp.

You do lose a lot of lubricity, 205 F is design temp on most oils IIRC.

 

[Fingers]

180* to 225* from what I have read. That would be the ideal going into the oil galleries. Hot side from the pan will always be higher and does not indicate what was used to lube the bearings since the primary heat source is the pistons.

 

[S Phinney]

So, Then what is the reasonably safe engine oil temp. and where is the right place to measure that temp. at?

 

[Turbotug]

My average unloaded oil temp before installing the TD-EOC was 220*. Add a load and it was on the rise..

 

[Accelerator]

Great topic here.

Lets talk about the rate of fluid temp heat transfer related to viscosity, as in what viscosity moves or transfers heat faster. also the heat transfer of dino vs 100% sysnthetic.....

lots of topic here, any bites?