Car #: 68
Year : 91 Posts: 2359
Yes, overkill. With mobile1 5/30 I change it when I start to hear the lifters after a session, which is somewhere around 3 weekends. When I was breaking in the motor and using dyno oil, the lifters starting making noise after one weekend. Wonder what that means
-------------------- Bruce Wilson 2010 Oregon Region Champ 2010 Monte Shelton Driver of the Year 2010 25 Hours of Thunderhill E3 and Under 2 liter Overall Champion Oregon Region SM Class Advisor
Region: Milwaukee+Midwest council madison club
Car #: 36
Year : 93 Posts: 254
I use RP I go by my step father/ mechanic rule of thumb. I look at the dipstick. when it looks dirty I change, now. not one more race, now. it works out to about 200 miles on my car, and the way I drive.
Region: Waterford Hills
Car #: 38
Year : 96 Posts: 348
Amsoil 0-30 every three weekends with a 1% leak motor. If the motor has 3% leak with most of it on the ring side I would change it every 2 weekends. If it has +10% leak don't bother anymore its not worth trying to protect it anymore.
-------------------- Ralph Provitz #38 2008 WHRRI SM Champion 2008 WHRRI Top 10 Overall V2 Motorsports, Race support, Data Dude
Car #: 08
Year : 95 Posts: 644
Wait ... You mean I'm supposed to change the oil? No wonder... Seriously though I have the same oil in the car for the last 4 years. Of course I only run the car once a year anymore. Its Mobil 1 and I'm not too worried.
Region: NWR/Oregon; ICSCC
Car #: 70
Year : 1991 Posts: 1111
I did 9 race weekends this year, and changed my oil (Mobil 1 10W-30) 5 times. There's no science in my method; it's just that I have the car up often enough that it's easy to change the oil every two weekends or so. I do a test day with about half the weekends, and I almost always do two classes.
My motor is very tight, and burns very little oil.
[ 10-27-2008, 10:29 PM: Message edited by: Mark de Regt ]
Car #: 13
Year : 92 Posts: 2873
If the motor is tight as was mentioned above, changing every weekend or two is overkill. A lot of the guys I race with burn half a quart a weekend or close to that. If mine did that I would change oil all the time and rebuild. As is, I last changed my oil in May. I have seven weekends on it sense then. Three of them were just one day. The oil still looks clean and there is no gas smell on the dip stick. I have also added zero oil in that time. I think it all depends on the motor. Mine didn't really need it so why bother?
Do what you want or feel good about. Mobil 1 is working much better for me than dino did. I just don't think these motors need anything exotic.
-------------------- ---------------- Z Brothers Racing / East Street Auto
Car #: 02
Year : 1991 Posts: 41
Contrary to popular belief, you cannot tell what state your oil is in by looking, smelling, feeling, tasting, whatever. The only way to KNOW is to have it analyzed in a lab. Having said that, it is pretty cheap insurance. I change about every other race weekend and change the filter every other oil change. I have been running Mobil1 with their filter, but am thinking of trying the RP, as it is available at Walmart and only a few cents more expensive.
So Oil... Sorry I am a major nerd and Dad is a Chemical Engineer with a oil company. Here's the technical take on Oil.
Oil is limited by a few major factors of which time/miles/temp and water pollution via condensation are the most significant.
IE. The miles it takes to "go through" the life span of your Oil is dependent on the temperatures that the oil experiences, as the hotter the Oil gets the faster it will Oxidize and therefore breakdown.
Now, the oxidation process is also influenced by miles. So if the Oil experiences normal temperatures (street driving) the very conservative 'median life expectancy' for Dino Juice is 3000 miles, more for Synthetics (as much as 10-20,000 miles).
However, a major factor in shortening the life expectancy of Oil is water. water pollution via condensation in the crank case should be a major concern to anyone who lives in a wet or very humid climate. Water contributes to the oil break down and a loss of efficiency. It is very important that in these climates that you follow the 3-6 month rule, allowing oil to only sit in a street car for a shorter amount of time instead of only relying on miles.
Here's the caveat. Long high speed drives improve the life expectancy of oil. What? Yes, it burns off the water and because the engine is running at steady temps in a breeze the temps are pretty steady and rarely "spike" like it would at say a traffic light or idling waiting for the Wife to re-check everything before you drive away. hehe
So, you get good life expectancy from Oil in track cars that maintain a steady Oil temperature. If your engine runs hotter than normal or you miss shifts on a regular basis, your Oil is tortured, and should be changed frequently. If you're a pretty accurate driver & rarely over-rev the engine and in general see normal temps (& live in LA or Arizona) then you could get a lot of miles from your oil.
However... This being said... YMMV and frankly as the other guy said - cheap insurance cheap insurance cheap insurance.
Note: Pro teams change the oil after every race to look for metal and other contaminants in the oil for signs of engine wear. Not usually because the oil is bad. (put a big magnet at the bottom of your oil drainage pan and swish it around - any metal will collect on that magnet (yay for cast iron blocks!)
Again - let your own conscience and gut guide you, not some random thing you read on the interWebz.
Anyone using oil analysis from someone like blackstone labs? It's very common in other race venues, and they give plenty of feedback about what is wearing, if you could use the oil longer/shorter, if you need a different oil with certain additives...
Region: Northwest, Oregon
Car #: 79
Year : 90 Posts: 3336
quote:Originally posted by ExRoadRacer: However... This being said... YMMV and frankly as the other guy said - cheap insurance cheap insurance cheap insurance.
This probably wasn't clear, but that was me making fun of the people who continually parrot that "cheap insurance" line no matter how much data they're confronted with. But again, that's coming from a cheapass racer with cheapass engines. If I had a fancy motor I'd be doing whatever my engine builder told me to do.
-------------------- Crew Chief, 3D Racing #64, aka Team Scrappy 2.0 3rd place E2, 2009 25 Hours of Thunderhill
Crew Chief, EGR/Miller Motorsports #64, aka Team Scrappy E2 Champions, 2008 25 Hours of Thunderhill