911racer

Hi all,

I have a 964 911 based race car. This car is all out, non-stock.

At the races this weekend, the temperature rose up to and over the 250 mark, this caused the oil in the relocated oil tank to smoke and come out of the tank (tank located in the smugglers box)

I am running a basically stock 3.6L with cams. I run a restrictor plate to be legal for my race group, so it is not a highly stressed motor. I run 93 octane pump gas. It is run off of an electomotive fuel and spark computer.

The oil system consists of AN-20 lines going from the oil tank to the motor, from the motor, the oil goes to a mocal thermostat, through a filter to a pair of coolers and back to the oil tank.

I pulled the filter apart to check for anything bad looking there and the filter looked good.

The temps of the day were not bad. In the 80's. I have not had any problem like this before. Usually getting the car up to temp was more the issue. The problem started on Saturday during qualifying. Nothing happened during that session to cause a problem that I know of. I ran the car Sunday in qualifying and most of the race before the problem got too bad. (better on Sunday than Saturday - we made some better air ducting to the coolers)

My wideband air/fuel showed good numbers. The coolers were about the same temp as the oil tank, so I know they were getting oil.

This is what I have planned for next.

1: drain the oil and check for any metal parts.
2: perform a leak down on the motor.
3: pull the mocal thermostat and check function.

Any suggestion for other next steps.

Thanks

Ed

MUSSBERGER

If everything else checks I would be looking at some type of restriction in the oil cooling system.

BlackPearl

Without knowing the air circulation it's hard to say what's up. If the tank and the oil coolers are the same, that just means the oil hasn't lost any heat travelling from coolers to tank.

Are there fans on the oil coolers? Are the coolers full of grit, sand, or tire "marbles?" Are there any obsrtuctions to air flow in and out of the coolers? Have you tried blasting air from behind the coolers to blow out debris?

Hint: I once took the A/C condensor and radiator off my old 944 for a spoiler fitment/front valence replacement and discovered the condensor was filled with sand. After "tapping" the sand and grit out of the condensor (and cleaning the fins of the radiator) the car ran 40-degrees-F cooler. What was surprising was, I couldn't see any of the sand in the condensor body when looking at it.

911racer

There are no fans.

Here is a shot of the car so you can see how the oil coolers are arranged. They are 993 GT2 style coolers and front end.

I am looking at everything, but so far there is no restriction. I am taking off the thermostat tonight.

Thanks

Ed

MUSSBERGER

I can't see where there would be an air flow problem. Thats two giant openings. I have a carrera cooler on one side and a mocal on the other with much smaller openings.

jakeflyer

Needless to say, you had the correct amount of oil. Is it possible that the temp sender unit could have a problem, wire attach point tight, wires to the gauge frayed damaged, or the gauge itself malfunction or connector tight?

Really nice car, congratulations.

racing97

If you have the counsel type coolers in each front fenders and have had any off track excursions the cooling fins will get filled up with debry. Blow or use a high pressure washer from the wheel well opening towards the front and clean them up.

regards

pu911rsr

Do you know what kind of A/F you are running it is possible that the restrictor plate is leaning out motor, this will cause them to run hot.
Phil