Oil temp as it is affected by coolant temp?

[jalopiejoe]

I'm new to the Forum and I hope I'm posting in the correct topic!
I recently read with much interest, Motor Oil 101 by AE Haas.
What I am wanting to know is....
What is the perfect thermostat temp to promote a 212 degree
oil temp?
I'm running a new 383 SBC w/cam & carb, no emissions or sensors. I live in Phoenix AZ. & most of my driving is in 65 to
115 degrees weather. In our cooler weather will a 180 water temp heat the oil enough to burn off the moisture, carbon, etc?
If I run a 195, in the summer I would expect a 220-225 water temp in traffic.
I'm running 10w-30 Amsoil Z-rod for my flat tappet cam, with a Mobile 1 filter.
Seems like most Hot Rodders are afraid of 200+ water temps and from what I read I need at least that temp to promote a healthy
engine internally!
Give me some input on this!
Thanks! Joe

 

[Highline9]

My challenger oil almost always runs 10 to 20 degrees warmer than water at cruise. Going 80 from barstow to hesperia oil runs around 220. I run a 185 thermostat. You need an oil temp gauge.

 

[Mitch Alsup]

What you want is an oil cooler with a bypass thermostat so that you control the oil temperature not by the water temperature, but by the actual temperature of the oil. Oil gets hotter than 212dF, bypass opens and cools it down. Oil gets cooler than 212dF thermostat closes and lets it heat back up.

Don't forget to open the bypass when draining the oil at the OCI.

 

[SteveSRT8]

Joe, I have a built up small block stroker as well in a small healy replica.

With a custom aluminum radiator and a small electric fan I run a 195 thermostat. Note that the hotter the cylinder walls the LESS wear, and you want that oil HOT.

My water temp never goes over 200 or so, oil temp stays around 220 in heavy traffic stop and go driving with bursts of fun.

Note that I have a big oil pan and this is why I want things to heat up a bit. You may have to adjust your timing if you get any spark knock.

 

[Shannow]

Couple of dot points, and the magic 212 isn't magic in anyway shape or form.

I've bought a few cars, and loathe the traditional cooling circuit.

One of them, a Holden 253c.i. V-8 had been run without a thermostat for a long, long time, and had massive ridge wear at the top of the cylinders, way worse at the front, bethed in cold coolant. The valve guides (for want of a better term) were visibly oval, and if you can see oval, then it's oval.

That proved to me early on that SteveSRT8s assertion re coolant temps is correct.

Later, I tried thermostats on the engine coolant inlet thermostats to stop the cold shock when the "cold" water from the radiator hits the front cylinders, while taking time to get through to the thermostat, close it a little, and let the rest circulate and "warm" up again.

Here's one that I had a machine shop make (and it ended up on one of Gary Allan's Jeeps a decade later).

I've got a billet one hidden in the place somewhere, that I've been dying to find since buying the Caprice with L67.

This would have a cold radiator in winter, as the control volume is that between the recirc hose and the thermostat bulb, rather than 5 quarts of engine block.

This will get you low cylinder wear.

And back around on topic, providing temperature to the bulk oil in the sump doesn't get rid of water.

I've gotten rid of water from many oil systems in my time as an engineer, and what you need is temperature and surface area.

If you can keep the cylinder wall temperature right, then you will have ample surface area, and a nice flow of air/blowby to carry the water away.

 

[Astro14]

both of the Steves (SRT8 and Shannow) have it right...interestingly, my '32 has a full flow cooling system...the coolant circulates unrestrained through the radiator, but the airflow through the radiator is managed by the thermostat via a shutter system...complex, but elegant: no thermal shock.

And through the oil pressure, I impute the oil temp, and it takes a while for the oil to get to temp. Interestingly, in a modern car, the coolant warms quickly while the oil warms slowly...but in the Packard, they warm at a similar rate. Because of condensation, when I do run the car, it gets run for a long time...as Shannow said, it takes temperature and surface area (it doesn't need to be 212F, there is a pretty good vapor pressure at 180F)...and I would add that it takes time as well. That's part of why highway miles are so easy on engines...

I would also add that my Volvos (all 4 of the ones I have owned...) circulate coolant through the heater core until warm, so the block heats quickly and evenly, the heater works sooner than in any other car I've ever owned, and it's my contention that this is part of why Volvo engines last such a long time...

To answer your question, re: 180 degree thermostat, I would install a oil temp gauge...

 

[mechtech2]

Originally Posted By: Mitch Alsup
What you want is an oil cooler with a bypass thermostat so that you control the oil temperature not by the water temperature, but by the actual temperature of the oil. Oil gets hotter than 212dF, bypass opens and cools it down. Oil gets cooler than 212dF thermostat closes and lets it heat back up.

Don't forget to open the bypass when draining the oil at the OCI.


^If you really want oil temps that hot, this is the way to go - the way to control it.^

Engine and trans oil temps are also greatly affected by ambient heat.