Re- using oil from a race car

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Hi All

Here's the question. At Uni, we build a car for a competition called FSAE. Pretty much design and build a car from scratch to race against other Unis. We run a R6 motorbike engine and use moto specific oils and have tried 5w30 (motul 300v), 10w40 and 20w60 oils to do get data for the car (we're having surge problems)

Each fill (4l, custom dry sump) is in there for less than 5 hours. I have filtered and kept the used oil, and I'm after people's opinion on using the oil again in road cars (mostly beaters)

How badly does racing affect the oil? I'd guess it has sheared a little and discolored due to high temp, it just seems a shame to waste double ester oil after 5 hours use! what's the consensus?
 
Depends on the kinda racing really.

I dunno. For beaters? Fine. But its impossible to know what kinda fuel dilution the oil may have suffered.
 
Without a analyst my biggest concern would be fuel dilution. But if we are talking oil for a beater I would not worry about it too much especially if you are not attempting extended OCI's. I am telling what I would do in this situation. But I do a lot of things I do not recommend others to attempt.
 
As far as fuel dilution goes, we run the engine leaner than factory (minimum 13:1 a/f ratio) because part of the competition scoring is fuel efficiency. I'm guessing this means fuel dilution is less of a problem...

The racing we do is autocross, laps around a kart track with heaps of cones. Each run is short, <20mins
 
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If you're not running them real rich, or running them extremely hot for a long time, more than likely I'd say the oil still is "ok". I wouldn't throw it in a good car, but if it's one thats drinking oil like it's water, then I'd say you're fine.
 
5 hours on the oil? Are you kidding? I would run that in a NEW car in a heartbeat! I don't think there would be any fuel dilution, but even if there was it would quickly burn off in normal highway driving. Thats good oil, just 5 hours old!
 
In a passenger car engine that has no real issues, any residual fuel should be evaporated in a couple hours of normal operation...
 
Fantastic. Thanks for the advice, I will probably blend it with a HDEO for the beaters- ester + calcium cleaning goodness!
 
So, you have decided that the oil should not go back into the race engine and it may be OK for your beater. Where do you draw the line?

Also, how do you filter the oil? How large of a particle will make it through your filter?
 
I filtered the used ATF from E430 to use in the LS400 leaking power steering this way:

Stub 5-6 paper towels tightly into the long ATF funnel, place the funnel into 5-qt jug then pour ATF into the funnel. The ATF is filtered at the rate of less than 1/4 pint per hour. For 4 quarts it took more than a day.
 
Originally Posted By: HTSS_TR
I filtered the used ATF from E430 to use in the LS400 leaking power steering this way:

Stub 5-6 paper towels tightly into the long ATF funnel, place the funnel into 5-qt jug then pour ATF into the funnel. The ATF is filtered at the rate of less than 1/4 pint per hour. For 4 quarts it took more than a day.


wow a real redneck filter, I would do the same.
 
Low cost (5-6 paper towels) with good filter, what not to like ?
grin2.gif
 
That would be interesting! I filtered the oil in a trans funnel, using layers of fine weave cloth as a filter. It also made me realise how different a 5w and 20w oil is at room temperature!
 
Originally Posted By: HTSS_TR
Low cost (5-6 paper towels) with good filter, what not to like ?
grin2.gif



I bet those blue paper towels they sell for the garage filter like a pure one.
 
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