Gus

Doing DE’s how many hours of run time/ weekends do you do before changing oil on an air cool engine?
Just had a friend ask and it got me thinking. I change every 6 weekends - just wondering if not often enough or to often??

Slow RSA

I have **heard** every weekend or two but have not verified that with the pros yet. Look into valve adjustments, too, that is supposed to be on a much more accelerated schedule for track cars like oil changes are.

stownsen914

Assuming an average trackday means 1-2 hours of track time per day, I usually change after about 4 trackdays. My track cars have all been older, mostly air-cooled, for what it's worth.

Sboxin

We do twice a year if running 8 weekends a year or change before NASA Nationals . . . but we use Amsoil Race oil and send a sample to the lab for testing each oil change.
The type of oil you use and whether you do lab testing is important in keeping a record of engine wear . . . . just my opinion . . .
Best of luck with your track driving.

Regards,
Roy T
Crew Chief for son's 78 911 3.8L race car

winders

How big is your oil tank? What oil do you use? What has been the ambient air temperature at events since the last oil change? Are you good at keeping the engine RPM up?

If I had a stock oil tank running a quality synthetic in the South during the summer, I would change it every other track day. But that's me....

911 Rod

For DE?
I change mine once a year. 10 days of DE.

bgiere

15ish hours if you are running a decent oil..Can easily go 20 hours or more if you run high quality synthetic and you don't have fuel dilution and your engine is properly tuned. Remember you have 12 quarts in there ! We have done used oil analysis for years.

Kein_Ersatz

Blackstone Labs Oil analysis to understand if you are going too long. Spike in Metals ppm will indicate if the oil isn't doing its lub-ing job or that something is in need of major service. Start with a short baseline and then adjust from there based on consistent results. But of all the expenses, in air cooled track cars, frequent oil changes is high value for cost. Getting under a track car to just change the oil/filters, like pads/rotors is a good habit to get into with track cars. I have been going 6 weekends (12-18 days) without any jump in metals ppm and I am satisfied there as a duty cycle on Mobil 1. I do go thru a Qt ~ 2 / 3 weekends, so some new oil is finding its way in there :-) Wide open throttle is another measurement of "stress" on oil compared to autobahn use (if you have that data). Some racks are a lot more WOT then others. YMMV.

Enjoy the ride!

Mahler9th

The gentleman that builds my engines also builds Winders' engines. He has 40+ years of experience and is an ex-IMSA racer. He worked with Bruce Anderson and Jerry Woods back in the day, and has worked on and built a variety of air cooled Porsche engines, including factory racing mills.

I have a stock tank, and I have only run synthetic oil during my ~20 years of track driving and racing my car (I currently use Red Line racing 40 weight).

His advice to me has always been "every two events" which in my use case is 10-12 run sessions/races (each at 20-35 minutes nominal).

Conekiller

Every 5 track days for me which is about 10-12 hours of run time. I use vr1 20-50.

stownsen914

One thing to keep in mind is there are multiple reasons for changing oil. One of course is that the oil breaks down. Using a good quality synthetic can extend this. The other reason is to remove the impurities that naturally build up in oil, which naturally increases in a track driven car. To my knowledge, synthetic oil doesn't reduce this effect.

T&T Racing

Blackstone Lab testing is the most analytical way to decide on frequency of oil changes. You can extract a oil sample thru the AOS .

altonj

Winders/Mahler9th said it perfectly. Stwonsen914 last post says what is commonly missed regarding synthetic oils and longevity. Another way of looking at is this: How much does an oil change cost? How much does a proper engine rebuild cost?

T&T Racing

If you do not test the oil even with frequent all changes,
you do not know what is happening inside the engine.

Frequent oil changes are not clairvoyant, but using the wrong oil specs or not testing the oil leads to s**t happens.

The only clarification is frequent oil changes helps if the engine oil temperature exceeds the oil specifications

My experience is a race car not a street/track car.

Tripp993

Rothsport recommended that I change oil and transmission fluid every 6 hours or 3 weekends.