MJM

I used to see 300+ engine oil temps running in 80 degree weather within 5 laps. With DRM's radiator and engine oil cooler today I maxed out at 265 oil temp at the end of 20 minute sessions. Outside air temp was over 100!

Thanks Randy,
Matt

gkmccready

Me too! I was hitting 300F+ on the oil and didn't pay attention to the water. Put in the DRM/RD combo radiator on my C6 Z51 and water basically sat steady between 195-205F with a stock thermostat in the car. Oil temps were similar to yours which was a great difference!

AtomicZ

+1 for the DRM set-up. My oil temps now run around 235

0Randy@DRM

TJM

300 degrees is way, way to hot?

I don't see how the motors live with those oil temps?

265 degrees is hot, that is the threshold of "nervous"?

I would propose the gauges are reading 20 - 30 degrees high????

No doubt the coolers work, mine dropped oil temps 40- 60 degrees. Now oil runs a balmy 210 degrees

TJM

0Randy@DRM

This is the nature of all C5 and C6 corvettes. Hot hot and hot... You should check the diff temps There is no way 100's of cars have bad temp sensors.

Randy

MJM

Well I ran a 2001 Z06 for 3-4 years at those oil temps and now I have run this 2000 FRC for about 5 track days at those temps too.

Mobil 15w-50 helps keep the viscosity somewhat reasonable at those temperatures.

While the engines are capable of living at those temps, I didn't like the power loss as the computer dialed back the timing and I HATED having to baby the car for a lap or two every 5 laps to get the temps back down.

Now I just keep the hammer down for the full session!

Matt

Olitho

In some research I did a while back, as I recall, the synthetic oils don't start breaking down and losing their lubrication qualities until 355 degrees although I imagine sustained use at high temps significantly lowers the lifespan of the oil necessitating more frequent oil changes.

Don't go on my word though, do your own research to validate my findings that I don't fully recall as it was four years ago that I did it.


Oli

CorvetteZ51Racer

The concern at those elevated temperatures is less about oil viscosity per se than it is changes in running bearing clearances. On rod bearings, which are all steel journals, it's viscosity. But on the main bearing clearances. keep in mind that LS motors, being alumimum block motors, have significant growth in main bearing clearances (where the block side of the bearing assembly is backed with aluminum, though the cap-side is steel) as temps go up. When I used to build engines at Roush-Yates in NC, which were also aluminum block, we would see the bearing clearances double from ambient to 210 oil. The growth from 210 oil to 300 oil would be another 0.0007"-0.0008" which is significant. If we saw oil temps rise above about 270, unless it was during the race, we'd shut it down.

FWIW, we did some controlled oil testing on the dyno and consistently found Mobil 1 to run the coolest and make the most power.

What I would recommend is, if you break 270, back off, cool down and hit it again. Then, when you get home, order an oil cooler.

Pumba

Great information !

I was at a Corvette Corral during a Mid-Ohio ALMS race and a Corvette engineer attached to the Pratt and Miller cars told the assembled Corvette owners that the P&M ALMS Corvettes shut their engines OFF if water temperature reached 190 degrees F.

He also stated that their oil temperatures were in the 210 degrees F to 220 degrees F range.

-

CorvetteZ51Racer

I'm a little surprised that they build the motors quite that tight, but one thing to keep in mind with race cars is that you don't run a thermostat on a race engine. It's just something to fail, and when they fail, they fail closed. Temperature control is typically done by adjusting the air opening to the radiators, and the lower you can design the engine to run at, the better off you are because you'll be doing less taping of the front at the cooler races. The more taping, the more drag and the more front downforce you have, which affects balance. Having to change the amount of tape from practice or qualifying to the race simply because of time of day differences can affect the handling of the car. Ours were built to run at 190/220, and we shut down at 235/270. During a race, we left it up to the teams, but if they went over those temps and they continued to run, it became a "you break it, you buy it" deal at $52k per motor.

MJM

Getting back to the topic of stock LSx aluminum engines....

The T1 guys tend to laugh at the temperature warnings. They use Mobil 15W-50 and coolers.

Additionally, most driving schools (Spring Mountain, Bondurant, etc) that have run C5s and C6s do just fine running them hard in the desert heat all year long.

I was perfectly comfortable with the temperatures I was seeing before, but now with my DRM radiator and engine oil cooler I can push hard all day long and just have fun. In fact, I had so much fun on Monday I corded my tires!

Matt

dfinke23

I am in the market for a combo rad. I went to their site and only saw the Ron Davis, and nothing for the C6Z. Did I miss something?

MJM

Give them a call tomorrow and talk to Randy, I'm sure he can set you up.

Matt

0Randy@DRM

The c6 has a million options for cooling. Give me a call and we can sort it out and I can hopefully explain the differences. We have sold a ton of stuff for the C6.

Randy
763-477-9272

Timz06

If you want proper cooling get a separate air-oil cooler. My T1 car oil temps were 225 or less running back to back 25 minute sessions at VIR in 90 degree heat. The guy next to me had a combo rad and his temps were up in the 270's running in the same conditions.

Tim

dfinke23

I am running the air-oil cooler that comes on the C6Z, and it's not cutting it. With a 468 LS7 I think I'm going to have to run a combination between the stock cooler and a rad cooler.

dfinke23

I'll talk to you later today.

AtomicZ

I have a 454 LS7 and the boys over at DRM fixed me up. I was running way too hot on the track. Randy will get you sorted out properly.

C6RAPTOR

Was this the DRM/Ron Davis radiator with built in oil cooler?