Camaro XV

[Kenny]

Originally Posted by Stielow

The Mule had a oil to water oil cooler built into the end tank of a Griffin rad. It held the oil temp down to under 250F for 3-5 laps. The turbos drive a lot of heat into the oil. One issue I have found is some of the older gauges don’t read high enough for synthetic oils. Redline has told me there engine oils are good to 325F. The Mule gauge pegged at 250F so we were shutting off early. Jackass has a relatively stock LS9 in it and it has no cooling issues on track with its Ron Davis rad with an oil to water oil cooler built into it. Red Devil runs a stock LS9 oil to water oil cooler mounted to the side of the engine. Once we had that car fully tuned up it would over temp the oil and the water in 5 laps on a 90 degree day. On Mayhem I upped the rad and moved the trans and diff coolers to the back of the car. In a 5 lap session the water temp was great and the oil temp is getting marginal. That oil cooler is built into the rad as a oil to water cooler.

On Camaro XV we upper the rad size even more with a custom core from Dewitt. I met with C&R rad at SEMA and they steered me to a larger 13 plate oil to water oil cooler that should keep my oil temp good. I have opened up the front of the car with the new Anvil front clip. I’m using my vented hood again to help move air through the rad. Dewitt is also making me a one off intercooler heat exchanger that will nest into the cooling stack to maximize core face and air flow. On Red Devil, Mayhem and Camaro XV I’ve ran a very large powerful cooling fan. It is a 20 inch dia Caddy SRX Turbo fan what pulls 850W. I like oil to water coolers because it heat the oil then cools the oil. It also makes a very clean installation. Dewitt is finishing the cooling stack next week and I hope to have some photos to post.

On a side note the LS9 based engines have oil squirters that shoot oil on the bottom of the piston to cool the pistons. Thomson modifies the LS7 block to add the piston squirters. He did a lot of testing to sort out the size and the location of these squirters. This does drive oil temp. Also as the power goes up so do the heat rejection requirements.

On your question on oil line sizes. I’ve been running -10 AN for cooling lines. I have run 12 AN but the 10 AN seems fine. I don’t have the sizes of all of the different coolers, sometimes it is hard to get the heat rejection rates or to know what you need without just testing it.

Hope that helps

Mark

Have you considered making a portion of the radiator into an air to air oil cooler? The reasoning is that on some of the endurance race engines I produced used only half the original radiator area for coolant and the same amount of area as an oil cooler. What we found is that we were still able to keep cylinder head temps under control while dramatically increasing engine life and reliability while allowing for tighter ring side clearance and using narrower rings with no loss in reliability. Valvesprings that would fail after 3-4 races would last all season with oil temps at 180-190° instead of 250-260°, and they would only get freshened up because the engine got torn down in the off season. We no longer had problems with rocker shaft or pin seizures, or hydrodynamic issues running a considerably lighter oil.
The original thinking on my part was that synthetic oil was good to X° so as long as it stayed below that....... That was wrong thinking. Turns out that when it comes to metallurgical strength of piston and valvespring materials, cooler is way better. Keep in mind that 5w20 at 190° has the same viscosity as 15w50 at 270° and the protection is not better with heavier oil when it comes to the EP package. I know that you have enough of a grasp on tribology to deduce all the other advantages. The same held true for differentials and transmissions....... less/lighter oil always equaled more power and lower temps improved durability. I found that 180° was sufficient for moisture evaporation in the crankcase, and 140-ish was awesome for clutch plate life in auto trans and clutch posi units. Just some food for thought

[Vegas69]

It wouldn't work anywhere but a road course Kenny. Idling around in traffic on a hot day is a challenge as well.

I also like the oil to water heat exhchanger for the reasons Mark stated. I found that it didn't work well with my car at only 660 hp. (Big Block) The air to oil cooler made a big difference over the water to oil exchanger.

Mark, what about a large air cooler with a removable shroud or plumbed with ducting and a servo motor?

[Kenny]

Originally Posted by Vegas69

It wouldn't work anywhere but a road course Kenny. Idling around in traffic on a hot day is a challenge as well.

I also like the oil to water heat exhchanger for the reasons Mark stated. I found that it didn't work well with my car at only 660 hp. (Big Block) The air to oil cooler made a big difference over the water to oil exchanger.

Mark, what about a large air cooler with a removable shroud or plumbed with ducting and a servo motor?

We kind of found the opposite to be true. I was putting out quite a bit more power per cu/in NA than this build with a blower, and the air to oil worked best. The thing about using a thinner oil at reduced temps meant it did not have to be heated by the engine because of the flow rates at lower temps. Our 5w20 oil lasted much longer at lower temps without breaking down, than hotter 20/50 race oil. Keep in mind that the coolant basically keeps combustion temps under control and cools the oil by cooling surfaces that the oil contacts. Virtually all the cooling of critical parts is done through the oil, which makes the coolant a middle man of sorts.... just using a fairly small portion of the radiator area for the cooler. We kept our head temps at about 230° for best power and the ability to keep it stabilized. The cooler oil greatly reduced cooling system load..... I guess I am kind of pushing this idea because oil temps are so critical to component life.... I'll stop it now


Okay.....now......

[Vegas69]

That isn't half and half but I can see that working great except in cold weather.

[preston]

Were you cooling the high pressure oil coming out of the pump or after it came out of the engine on its way back to the tank ?

Is there a preference ? Does it make a difference ?

I run a oil/water cooler on the pressure side before it goes into the engine. I like this because as you mentioned it also warms up the oil which is good for a street based car, but I was thinking of adding additional cooling capacity via an air to air. But packaging means I would like to put it on the low pressure side. Thoughts ?

[Kenny]

Originally Posted by Vegas69

That isn't half and half but I can see that working great except in cold weather.

That isn't actually what we used, but I saw it and thought it would be more along the lines of a streeter.
You just have to trust that the thinner unheated oil works better in cold temps than trying to heat thicker oil..... I promise. There would be nothing wrong with a pan heater though.

Originally Posted by preston

Were you cooling the high pressure oil coming out of the pump or after it came out of the engine on its way back to the tank ?

Is there a preference ? Does it make a difference ?

I run a oil/water cooler on the pressure side before it goes into the engine. I like this because as you mentioned it also warms up the oil which is good for a street based car, but I was thinking of adding additional cooling capacity via an air to air. But packaging means I would like to put it on the low pressure side. Thoughts ?

It really didn't matter as long as we passed sufficient volume to avoid starving the suction side. It really doesn not take long to heat a 0 or 10w oil. I guess if you are cruising in sub zero temps..... We also found power with a particular brand of dino oil over every synthetic we tested. It was the "fake" synthetic, if you will, the "superclean" crude that many companies pass off as synthetic.

By the way..... you guys do know they make a thermostatically controlled bypass, right?

[next69]

Where are the updates? Its been 10 days, we need a fix.

[WSSix]

Originally Posted by Kenny

By the way..... you guys do know they make a thermostatically controlled bypass, right?

Kenny already mentioned it.

[mikels]

Originally Posted by Kenny

By the way..... you guys do know they make a thermostatically controlled bypass, right?

Great source for thermostatically controlled oil bypass:

http://www.improvedracing.com/oil-co...ine-p-209.html

http://www.improvedracing.com/oil-co...gine-p-33.html

If cannot package (due to headers, frame, no LS engine...), can use this:

http://www.improvedracing.com/oil-th...stat-p-55.html

Having oil-to-water heat exchanger also helps warm up the oil after cold start, but still recommend having t-stat to control flow until desired temps are reached.

Nice feature on all these type bypasses is they never block flow to cooler, just open a 'bypass' to allow oil to return to engine prior to reaching temp set point. This allows some flow to always occur through cooler, so by time temp point reached and bypass is closed, not hitting engine with a slug of cold oil.

Dave

[Royalworks]

Originally Posted by Kenny

We kind of found the opposite to be true. I was putting out quite a bit more power per cu/in NA than this build with a blower, and the air to oil worked best. The thing about using a thinner oil at reduced temps meant it did not have to be heated by the engine because of the flow rates at lower temps. Our 5w20 oil lasted much longer at lower temps without breaking down, than hotter 20/50 race oil. Keep in mind that the coolant basically keeps combustion temps under control and cools the oil by cooling surfaces that the oil contacts. Virtually all the cooling of critical parts is done through the oil, which makes the coolant a middle man of sorts.... just using a fairly small portion of the radiator area for the cooler. We kept our head temps at about 230° for best power and the ability to keep it stabilized. The cooler oil greatly reduced cooling system load..... I guess I am kind of pushing this idea because oil temps are so critical to component life.... I'll stop it now


Okay.....now......

I completely agree with this statement. Back in my Honda days I swore up and down that everyone that was running a turbo needed to install an oil cooler even if it was small. 9.5:1 and 8-10 lbs of boost on a Honda got things hot quick.

I do have a question on that though. How do you control the temp if it gets to cool? Is there a sort of thermostat you are using or are you just letting the coolant take care of that?