[TurboS10]

Hey guys,

I want to talk about oil temperature a little bit.

Since getting the S-10 on the road again with an oil temp gauge I am wondering what you guys have experience. What I am seeing is that my oil temperature is running up around 230 after everything gets up to temperature. This is the temperature reading after the oil cooler in the main oil passage right above the filter.

As you might imagine, oil pressure is not great once it gets this hot. For the first few minutes of beating while oil stays around 200-210 oil pressure is pretty decent considering I am running all the bearings on the low side. It still idles with 25-28lbs at 230degrees, but it does not run real high as RPM goes up. I figure with oil temp running that high after the cooler it must be over 250 in the pan.....which seems high to me.

I am thinking that I definately need to go with a synthetic due to the base oil stability at higher temp. If I stick with dino oil I will have to change it after every few hours of run time due to thermal break down, but I am not too sure.

If any of you are monitoring oil temperature on different types of engines I would like to hear what you are seeing. Any input on oil life at high temps would also be appreciated.

The one thing I am not real crazy about with synthetics is the high temperature film shear strength. I have done alot of reading on the net and everything seems to come from an amsoil study of oil properties. Most of the synthetics in the test really suck on film strength except the amsoil...which makes me wonder. But, I had heard that the synthetics were not a good idea on a turbo engine due to the increased temp and the inabiltiy to maintain film at high bearing loads.

Another issue is zinc as a dry lubricant when the film breaks under high loads. From what I have found Valvoline Racing Synthetic has the highest zinc content, but it is a synthetic. Valvoline racing dino oil has the same zinc content, but I have not found a film test between the two so I am not sure which would be better.

I really think the zinc is a must and the Quaker State I am running now has none so I need to change. I will not be running any of the regular synthetics everyone raves about. They might be good for a regular hotrod or driver, but I am convinced they are not good for a high output turbo engine.

So, lets discuss......

Chris

[johnsongrass1]

Oil temps need to stay within 20 degree's of the water temps. 230 is a tad high for short periods of run time. The extra clearance you describe as loose bearing's is the main cause. Oil pressure seems okay to me. Once bearings temps rise to 280 with cheap bearings or 300+ with good bearing melt down isn't far way. If you can get some air over the pan or keep oil in the pan longer you will be able to get the temps down some. Agian, 230 is a tad high but not extreme. Are your turbochargers oil cooled?

[NXS]

Amsoil

They don't say it here but I think it lasts for up to 19,000 miles. I worked at a speed shop some time back and used it in an Rx7. It lasted for a really long time. Really long. it might stand up to your engine for a longer time than your average oil. it was $7 or so a quart on the shelf( but cost me two$ ea). Rather expensive but if you've got a buddy at the parts store...

See here also

[camaroman7d]

Chris,
I found about the same thing as you when it comes to oil temps. With my previous N/A engine my oil temps were much lower also had an oil cooler. With my blown engine my temps are in the same range as yours, at cruise RPMs there's no real problem but, if I start getting a heavy foot the oil temp rises pretty quick. I do not have a cooler on this engine because my pan didn't leave enough space for the sandwick adapter. I will be putting the cooler back on in my current project.

As far as synthetics go, most (if not all) cam companies don't recommend them for some reason. I found this out by calling around (Crane, Crower, Comp, Lunati, etc...). If you are going to run a synthetic oil stick with Amsoil or Mobil 1. I have been using Valvoline Racing oil for a while, it's just hard to find sometimes. You are correct it has a good ZINC content.

I have heard (but have never tried) deisel oils are supposed to be very good (high Zinc), I don't know this to be true or not, just something I read not long ago.

How did you plumb your oil cooler? Sandwich adapter? Or did you plumb it a different way?

Royce

[Rick WI]

First do yourself a huge favor and go to this link and talk with Terry. He is a pro on oil. Send him an sample and you'll be pleased with the feedback.
http://www.bobistheoilguy.com/terry.html

Your best resourse for information day to day is to simply search and or post on www.bobistheoilguy.com.

As was mentioned earlier oil temp should be about 20 degrees higher than water temp. I'd not want to go any higher than 250 in the sump with a dino oil.

There is absolutely no downside to running a synthetic versus a dino oil, ESPECIALLY on a turbo. I'd like to see the info you read on why a turbo should not run on synthetics. Never ever heard or read that. Would be interesting to see their logic.

A typical synthetic like Mobil 1, is an excellent oil that would be fine in your vehicle. Vastly improved protection over what you are running now.

In every one of our race motors, as well as my motor and our Extreme Street 1000 WHP nitrous big block motor we run Schaeffers 20/50 racing oil, a synthetic. It has a superb base stock and an excellent add pack. On the circle track cars after a 50 feature oil temps of up to 300 have not caused problems with wear.

Zinc is an extreme pressure additive. Very important for highly loaded areas like high lift roller cam applications.

[TurboS10]

Royce, I used a sandwich adapter and a smaller ford type filter. I think the cam companies dont recommend the synthetics because of the lower film strenght. Lobe to cam contact has to be right up there with the highest load in the engine. Especially for a solid flat tappet cam.

Johnsongrass, my turbo is oil cooled. That is the main issue with the heat, but the grouted block does not help.

Rick, the synthetic oil with turbo engines has to do with the high bearing loads. Cylinder pressure in turbo engines is very high as with any forced induction engine. High bearing load with lower film strength is not a good combination. I will talk to the oil guy.

Keep it coming.

[Cstraub]

As johnson said 230 is high for just short run time. It won't hurt anything but if you are seeing above 250 then you are getting into the warning category. Oil volume is going to be your friend. I just went through this on a marine board with oil temps and volume. Kinda like if you have 2 pots the same size sitting on the same size stove burners and both are on high, one has 2 quarts of water and the other has 4, which one will take longer to heat up. I would say Chris that you are going to be needing a 8 to 9 qt oil pan.

Chris

[NXS]

My old boss always put oil accumulators on his BMWs. I think this would be an ideal situation for one if you cannot keep temps reasonable. They would prelube the engine on each start-up as well as provide additional oil in the event of loss of oil pressure.

I thought synthetic oil was not recommended during break-in b/c it had such great friction reducing capabilities that it prevented the metals from breaking in properly.

[TurboS10]

Originally Posted by Cstraub

As johnson said 230 is high for just short run time. It won't hurt anything but if you are seeing above 250 then you are getting into the warning category. Oil volume is going to be your friend. I just went through this on a marine board with oil temps and volume. Kinda like if you have 2 pots the same size sitting on the same size stove burners and both are on high, one has 2 quarts of water and the other has 4, which one will take longer to heat up. I would say Chris that you are going to be needing a 8 to 9 qt oil pan.

Chris

I had to cut down an 8 qt pan to about 6.5 qts to fit in my chassis. I have to pull the engine to modify the pan, so that is not an option that I want to think about right this minute, but next time it is out it might be worth doing some welding I guess. The thing with the oil temperature is that it stabilizes at 230 degrees. I think that is the point where the oil cooler kindof catches up and the delta T is high enough to maintain that temperature. Of course that is with a 60 degree ambient temp as well.

On the track none of this is an issue, but for extended drive time while tuning it is. I did notice if I drive with no load for about 5 minutes it will come down to about 210.

Chris

[killerformula]

what about fabricating an external oil holding tank for your motor if you don't want to remove the pan?

K

[brainsboy]

To me that seems way on the hot side because your saying thats after the cooler. I had this problem with my Blown datsun. I'm not here to argue on which oil is the best, but I will tell you that I ran higher pressure with normal 20-50 then I could with any synthetic. I can not tell you why, just that it is a fact.
I have been doing nothing but cooling research and testing due to my current project which I think your familiar with, my suzuki samurai. Before I give any suggestions, could you describe your oil cooler setup? I would like to
know where the cooler is positioned, what size lines, how big is the cooler. does it have its own fan or is it in front of your radiator.

Ben

[TurboS10]

Brainsboy,

I have 1/2 inch cooler lines run to a 4 pass oil cooler with 1/2 inch tubes. The cooler is mounted to the front of the radiator with a pusher fan mounted directly on the front of it pushing air through the cooler and then the radiator.

Chris

[brainsboy]

Anyway you can post a photo of it?

[TurboS10]

Originally Posted by brainsboy

Anyway you can post a photo of it?

Out of town this week, but I can do this weekend.

[Cstraub]

If you have any 90's in the lines get rid of them. If it stabilizes around 230 that is not real bad, you want it around 210 to 220. But like you said it is cooler weather right now. Once you get some of that TX heat then things might change.

Chris