changing oil after track day - and solid motor mounts!

jwetering · jwetering's Garage

Went to the track yesterday - had a great day but at one point I had to run a coupla cool down laps because my oil temp went over 250

So the question is, do you regular track guys change your oil after every track day...how about if you get a little hotter than usual?

My car is a basically stock 3.0.

Oh and by the way I installed solid motor mounts in the back, with clubsport mounts at the trans. Sounds GREAT from inside the cabin, and the vibration is only barely noticeable. Shifting is better too.

John Rogers · 10-02-2002, 01:17 PM

I change the oil and cut open the filter to see what, if anything is inside after every race weekend. I figure it is cheap insurance, you'd be surprised what is in the filter....Good luck.

makaio · 10-02-2002, 01:33 PM

I change my oil and filter after every track day. Granted I only do about 3 per year. But I'm hoping to increase that # this next year.

pbs911 · pbs911's Garage

I do things backwards, and change the oil before a track event. Should the oil be changed after? I've never heard of a race car changing the oil after the race. It seems you want top viscosity for the event were you will be running the motor hard.

Dr. Chamblin, the postman just picked up the second part of the package. I had a huge brain fart.

911nut · 911nut's Garage

Mineral oil begins to break down starting at 300 degrees F. Even if you don't hit that it's still good to change your oil after every trackday.
PB

makaio · 10-02-2002, 04:46 PM

Thank you Dr. Sopp.

widebody911 · widebody911's Garage

I do mine before and after. I also change my trans fluid.

RazorRacer · 10-02-2002, 07:53 PM

My 78SC would run about 10 laps and then the oil temp gauge would hit the bottom of the red mark. Someone said that is about 250 degrees F. At the same time, the engine stopped performing and I only got about 60-80% power and the oil pressure would drop. When that happened, I'd take her in and let her cool down. By the time for the next session, she was ready to run (for about 10 laps).

I have put a cat bypass to help keep the engine cool and hope to see an improvement at the next DE. Also, I plan to start changing my oil after each DE.

ChrisBennet · ChrisBennet's Garage

A friend just went through this with his '78. He changed to the later venturi pickup/baffle, Carrera oil cooler and checked his external thermostat. It turned out to be in engine thermostat.
-Chris

RazorRacer · 10-03-2002, 06:45 AM

Chris,

Did his engine thermostat problem cause the performance of the engine to drop to 60-80% when the oil temperature gauge reached the beginning of the red area?

ChrisBennet · ChrisBennet's Garage

Quote:

Originally posted by RazorRacer
Chris,

Did his engine thermostat problem cause the performance of the engine to drop to 60-80% when the oil temperature gauge reached the beginning of the red area?

Yes, he experienced some power loss which made me think it was the sump filling up with oil - a problem '78's had before they went to a different venturi pickup. The engine thermostat was working but it wasn't opening all the way. His cooler would get hot so he didn't suspect the thermostat initially.
-Chris

rlane · 10-03-2002, 08:43 AM

I just went thru the same thing. I could run 20 minutes at track speed and then lost much power as she hit the red zone on the oil temp. My "trombone "oil cooler was warm but defintely not hot. So..in the manner of all P-car nuts I overdid it and installed new external t-stat AND a B&B cooler w/fans. Now I can't get it above 9 O'clock on the oil temp gauge. Headed to Putnam Park tomorrow!!!!

jwetering · jwetering's Garage

Indeed - my 1978 experienced a high temp, low pressure, loss of power episode at the track - this is what precipitated the thread.

My wrench and I figured that my scavenge pump gulped some air during hard cornering....typical early 3.0 problem. My oil temp hardly ever hits 210 under hard street/hiway driving so seeing 250 was quite a shock.

Thanks for the feedback guys - my oil has been drained, and I will be replacing the filter too, even though it was just done and the oil is still amber coloured.

RazorRacer · 10-03-2002, 10:19 AM

Chris,

Your friend checked his engine thermostat. How did he do this? These puppies cost about $200 and if there's a way to check it rather than replace it, please...do tell.

ChrisBennet · ChrisBennet's Garage

Quote:

Originally posted by RazorRacer
Chris,

Your friend checked his engine thermostat. How did he do this? These puppies cost about $200 and if there's a way to check it rather than replace it, please...do tell.

Pelican has them for $165. He tested his by putting it in hot water. When he compared it to the new one I think it's piston didn't "push" very hard.
-Chris

tshih · tshih's Garage

Bruce Anderson has answered this same question about 1978-1979 SC's having the poor pickup oil sump cover problem leading to power loss and high temp in oil. The fix was as Chris suggested, install the later venturi screen and make sure it is correctly installed not to block flow of oil to the pickup scavenger pump. Andersen also said if you continue to run with this problem it can damage the engine.

pbs911 · pbs911's Garage

Quote:

Oh and by the way I installed solid motor mounts in the back, with clubsport mounts at the trans. Sounds GREAT from inside the cabin, and the vibration is only barely noticeable.

I've been thinking about the solid/sport mounts. Could you elaborate on what is "sounds" great and "vibration" Thanks.

Wil Ferch · 10-03-2002, 11:03 AM

Guys:
Some misunderstanding here as to oil temps....
Most gauges of the late 70's and throughout the 80's went something like this :
- bottom white block 60 degC ( 148 degF)
- next up white line 90 degC ( 194 degF)
- next up white line 120 degC ( 248 degF)
- next up, bottom of red block 150 degC ( 302 degF)

Now for us guys used to the English system, these values can be nicely and quickly approximated by 150 /200/250/300.

Save your money...don't buy numbered gauges !
---Wil Ferch

jwetering · jwetering's Garage

Quote:

elaborate on what is "sounds" great and "vibration"

Ah..this is so subjective, but I will try.

The vibration question is easier to answer. There is some really quite minor high frequency vibration at low (2-3K) revs. I noticed it the first time I drove the car cold, and I must have gotten used to it because I really have to pay attention now to notice it.

The sound is difficult to describe. All I can say is that the car now has more of that tearing canvas sound reverberating through the cabin than it did before. This is especially more noticeable on decceleration. It sounds very racy - like the in car sounds from the supercup cars.

My car has no engine compartment sound pad, and I'm running a backdate exhaust so it was never quiet. I like mechanical noise...I'm sure my wife will hate it if she ever sets her butt in the shotgun seat again. She already doesn't like riding in the pcar because of the noise.

If you're ever up north we'll go for a ride.
cheers

Early_S_Man · 10-03-2002, 11:23 AM

Bruce Hermann (Gibson) did some thermostat comparison tests and posted the pics back in the spring. He used water, but I prefer oil for testing, as you can go to higher, more realistic temps. I prefer a thermocouple probe over thermometer, too, but that is not really relevant here.

engine oil thermostat test photos