I hate to post another thread involving Oil, but there are still some unanswered questions. I am running a 79 with a heavily modified 383. I finally got around to hooking up my Oil Temperature gauge last night. I was surprised to see the gauge was pegged out at 250*F. This is an aftermarket gauge, unlike the one that the general installed that went up to 340*.
I am running Joe Gibbs HR-1 15W-50 oil. My RPM's are 3,200 RPM's at 70MPH. I can understand that it might run a little warm, but not that much. What is the optimum temperature that this oil should be at? At what temperature will that oil experience thermal breakdown? What is the maximum temperature that this oil should be at. I installed a Dewitt aluminum radiator with dual Spawl fans. That really seemed to help the water temperature issue that I had a great deal. It is running at 190*. I considered installing an oil cooler but I have read too many bad things about these. Things like the potential for engine fires, and possibility of introducing too much crud into the engine. They appear to put the filter inline before the cooling unit.

 

Where is your temp sensor?
What kind of driving were you doing/ how long did it take to get it that hot?
Oil pressure?
How man quarts of oil?

 

I mounted it just above the oil filter.
I was driving to work and doing nothing uncivilized.
I am running 10.5:1 compression ratio so that I can still use pump gas(93).
I put in 7Qts. of oil.
It took me about 9 miles before it made it's way up to 250*.

 

The oil pressures starts out about 70 PSI and then drops down to about 40-45 PSI. once the oil is hot.

 

I would check the gauge... Shouldnt get that hot, that quick. If it really is that hot I would guess something is quite wrong in your motor.
It used to take me a 20 minute road racing session to peg my gauge (250*).
Now I really have to beat on it to get it to 190* on the highway even with restricted airflow to the cooler

 

Would you suggest an oil cooler? Will the Joe Gibbs HR-1 handle that temperature?

 

It's a new engine from Proformance Unlimited. It only has 1077 Miles on it.

 

I would verify that the temp gauge and sensor you have is correct before spending time and $ on a cooler. With no indicated coolant temp issue, no hard driving and no apparent reason for the oil to be that hot, I would first doubt the gauge. Verify it first.

 

I would do an oil change and cut your filter open and see if you have anything unusual in it. Or, you can send your oil off to be tested for conaminants. This is done in the flying world often.
If the gauge is correct, you may have some friction going on in there that could indicate some pending issues.

 

I'd use a http://www.harborfreight.com/non-con...ter-96451.html shot at the oil pan to see if it and your gauge jive.

 

Thanks for all the info.. Unfortunately, i'm just getting back to you all for I spent the last 2 days passes a Kidney Stone. I called Joe Gibbs technical support. They told me that the HR-1 is designed for wide tolerance engines and is capable of handling temperatures as high as 320*. He mentioned that I should only consider an oil cooler if i'm choose to use a lighter viscosity oil like a 10W-30. The HR-1 is 15W-50. I will buy anoth guage with a higher temperature reading, like a 300* - 340* guage.

 

Here's one more thought to confuse the issue. You say you have a highly modified 383 but you don't elaboate. If any mods have been done to increase oil flow past the crank such as cross drilling or grooving, that will increase temperature because it is removing heat from the crank. On past engines when we used to groove the mains for increased flow, it was common to see 250 temps.

 

No, I didn't have any elaborate machining done to the crank. I do have a high volume oil pump in there though. I am running 10.5:1 Compression that runs on 93 octane fuel. The water temp. is kept to around 195*.

 

Make sure the resistance range on the gauge's sending unit and your gauge match. I had a friend tell me his motor was running +250 and needed work, he changed the gauge brand but not the sending unit.... it was actually at 190. I checked the actual temp with a heat gun, and then used an expanded scale volt meter to get the readings. The gauge should have a "link" for resistance vs readings...

I have a 383 (in my other vet ) with a roller and I don't see temps very different than the water temp, maybe 20 - 25 degrees when pushed. The temp drops fast when I let it idle for a few minutes .. before the next run.

you can put the sending unit in hot water at 200 deg and check the resistance vs the gauge requirement resistance for 200 deg.

 

I have a 9 second drag car and I watch the oil temp closely because high temps indicate bearing failure. As mentioned check the filter for bearing material. Im not a fan of electric gauges as they seem to have lots of issues with sending units. There is no way the oil dhould be that hot.

 

One thing I keep forgetting ....... check you grounds, both gauge and engine...

 

whoever (and I have my suspicions) told you oil coolers aren`t safe doesn`t know WTF he is typing about....it`s pure fantasy land. 250* is pretty hot oil temp for a street car, imagine what it is at the bearing???

 

Fast highway driving gets me up to 250* . You want over 212 to steam off any moisture in the system. I would change gauges if yours only goes to 250

That oil temp of 250* is in a stock 82 crossfire running at 200* water temp @80mph

 

I installed a 81/82 oil temp gauge in my 78 L-82 in 1985 by relocating the oil pressure sensor to behind the distributor and put the oil temp sensor in the GM stock 81/82 location right above the oil filter on the block. It has always since 1985 run about 250 on the highway on hot days. It's normal! GM calibrated the gauge to 320 degrees because the oil temp sensor on these cars in the stock location reads 250 at the 12 O'Clock position on the gauge.

Also, not true that the oil temp needs to get above 212 degrees to burn off condensation. Ran a 73 Nova SS to 168,000 miles with the oil temp always less than 200 degrees reading from the pan bolt drain not above the oil filter. Also, my 2010 Z06 has never run above 190 oil temp on the digital gauge.

 

So, is there a definite difference as to where the sending unit is placed? What location would give me the most accurate reading?