Bri Bro

On the track, I get up to 250F on a stock engine in the summer on a regular basis. I am upgrading the turbo and the first thing on is a second oil cooler, then brakes and suspension and bearings. I am surprised that a track car could have the oil temperature stay below the water temperature of the engine.

RKD in OKC

The Scraper
The scraper is a ridge along the oil pan that helps pull oil off the crank. It does not COMPLETELY remove the oil on the crank. It is NOT a squeegie. In fact, because there is a gap between it and the crank there would be a tendency to provide more of a metered amount of oil to be slung by the crank than to remove all the oil off the crank.

Sloshing
Sloshing oil is NOT where the oil comes from to cool the pistons and walls. There is lots of oil draining down from the head to be splashed all-round by the crank. Sloshing oil lets the oil pickup come out of the oil and suck in air instead of oil. This can be more than momentary as air in the pickup line would cause cavitation. That is where the air bubbles in the pickup line expand instead of the suction pulling in more oil.

968 Squirters
The 968 has a different block design. The are a couple changes to make the cylinders stronger. The water jacket does not go down nearly as far so there is less water cooling to the cylinder walls. There is also a bracing skirt on the bottom of the cylinders to give them more strength. This skirt keeps oil from splashing on the sump side of the outside of the cylinder. While making the overall cylinder stronger, it also aggrivates the cooling problem, hence the squirters. Even with the squirters, it is not uncommon for 968 blocks to WARP due to the heat build up where the rings stop at the bottom of the stroke and the area not cooled because of the skirt bracing. Most of the heat of combustion that transfers to block is through the rings to the cylinder while it is stopped at the bottom of the combutions stroke.

RKD in OKC

Oil Temperature
This is something that really bothers me. I constantly hear of how additional oil cooling capacity is a necessity on track cars, yet these same owners remove the water cooling from their turbos. The water cooling system is much more efficient than the oil cooling system so why would you remove it from the one place where there is direct exposure to the highest temperatures, the turbo???

Kool

Where do you put your oil temp sensor?

sharky47

I am also curious about the water cooled turbo, and the lack of.......

anders44

250F is a good temp as water is boiled away but oil is not to hot, 300 is not, even tws motorsport startes to tear down over 275F

as of to oiltemps on theese cars I don't know what to expect, I have only had a 15min testrun so far but as it is a track only car I will see. if its to hot I will replace the cooler.

as for tempmounting I'm gonna buy a new plug for the oil pan with a temp sender, so it gets ground from that and you connect the other signal from a pin on the bolt/sensor

George D

Slightly overfill your oil and check it after each run. Oil temp sensor is vital. These motors can run and run under full boost as long as everything is kept up. Full boost lap after lap. Run a cool down lap prior to shutting down. This has nothing to do with the engine, but install a trans cooler if you are tracking. If you notice your temps staying over 250 degrees consider installing an additional oil cooler. They are cheap considering the cost of running too hot a motor.

The list goes on, but anything that helps keep things as cool as possible is money well spent. Don't run a stock turbo at 18psi all day. It will get too hot and actually slow the car down. Use good gas.

George

M758

Good oil and proper oil changes. Fresh rod bearings at a minimum. Baffled oil pan & cross drilled crank. Dyno time to make sure A/F ratios are solid. Keep oil level full, but not over full. Check oil before each session.

Stock boost!

RolexNJ

All good points Joe, more so being you're a racer who wrenches too. But come on pal, who runs stock boost? Everyone runs even a tiny bit over.

Van

I run stock boost. And two years ago, at Mosport, the PCA scrutiniers checked the boost pressure of all turbos in E class. I was on the money -- two people were actually underboosting, and the leader was over... that moved me up to 3rd!

Andial951

Does the 951 Cup oil pan have the baffles everyone is mentioning?

RolexNJ

I hear ya as far as running in a certain class and their parameters. I was just talking about the author though "Kool", who didn't mention he was running in a spec class? Regardless, good for you!