Oil changed every race -- What about the filter?

[burning1]

This question comes from a motorcycling specific forum:

Quote:
How often do you change your oil and filter on your race bike and/or track bike? Prepping an engine for the track bike, and it will have Megacycle Cams. They recommended using an ester-based oil like that of Silkolene or Motul at about $15.00 a quart. Yes, I know track days and racing is expensive, but it's not the price I'm really concernrd with, as much as the service intervals.


In the motorcycle racing community, some riders are known to change their oil after every event. Without getting into whether or not changing your oil after every 100 miles of extreme use is good or necessary, I'd like to ask a question about filters:

Does a filter's performance generally increase or decrease over the first hundred miles of use? Is it better to change the filter with the oil, or does the oil filter work better after it's had a chance to "break in?"

I'm interested in your responses. I'm linking this thread back to the original forum.

 

[Gary Allan]

In a true racing environment I'd say that filtering is secondary to the wear you're managing with the racing. I'd say that it's there for big chunks at best. Volume requirements are probably pretty high given the span between idle and red line.

I'd be more concerned if the can bulged.


I don't think I answered your question.

 

[burning1]

Thanks Gary. That's a good point -- if you're changing oil every race, there really shouldn't be much particulate in the engine.

Another line of thought... Would there be any wear or failure conditions you could catch by cutting the filter open after every race?

 

[Gary Allan]

My bracket racer buddies cut open filters every filter change. They're refreshing their engines every 2 or 3 seasons, anyway. It's just to see if anything is "unright".

I'd be cutting them open just to detect change. For all I know you could have glitter from the get go. I'm sure that my (long one here) daughter's boyfriend's uncle's mini (or was it micro) sprint running alcohol was shedding something every race. He was replacing rings and pistons constantly ..and every so many refreshes ..it was a new motor.

 

[CoreyDSFA]

Thanks for posting this Chris.

So my bike is oil and air cooled only, on top of what he states in his first posting. Track bike only, and oil-cooler, but no current accurate oil temperatures as of yet. Will have in August during another track weekend.

The engine I will be running in it, with the Cams burning1 has mentioned, require the special oil. The current engine is a stocker, and is runing 15w-50 full synthetic oil, and using the stock-type paper oil filter located up inside the oil pan.

Thanks for any replies.

 

[Gary Allan]

This might go better in the racing forum.

 

[Steve S]

Change the filter.

 

[sw99]

The guys I raced/rode with would do their OCI after ever race/ride like you mentioned. Almost all our rides were WOT everywhere we went.

On my YZ426, I would do it after every 20 rides or so and no problems. Never after every ride/race... But then again, I'm a cheap ba$tard...

 

[glenncof]

I'd worry about the big chucks during a run. Maybe that's why I've seen some racing filters with a screen on bypass valve. Wear will be detected during teardown but something coming apart during a run could be dangerous.

 

[Gary Allan]

Originally Posted By: sw99
The guys I raced/rode with would do their OCI after ever race/ride like you mentioned. Almost all our rides were WOT everywhere we went.

On my YZ426, I would do it after every 20 rides or so and no problems. Never after every ride/race... But then again, I'm a cheap ba$tard...


Are you talking about the filter? I would think the oil would be trashed way sooner than 20 events. Just the likely fuel dilution and (probably) lower efficiency air filtration would be cause to dump it. ..or so I reason.

 

[sw99]

No Gary, unfortunately I'm talking about the oil... I really wish I would have done a UOA on it when I still had the bike. I am so much more curious these days. This was almost always on the Yamalube racing oil.

 

[Gary Allan]

Quote:
I am so much more curious these days.


Me too, but I'm also amazed at what I got away with in decades past. Bird and boulders air filtration ..going as fast as one could in the space allotted 24/7/365. Seat belts

Thanks goodness I took so long to realize the errors of my ways. I don't know if I would have made it this far.

 

[sw99]

Amen brother!

I am curious how the racing dirt bikes compare to the racing street bikes in the engine wear department?

I also remember a bunch of folks were running the washable oil filters when they starting becoming available. Those always made me nervous.

 

[Gary Allan]

The dust/dirt issue is huge, I'm sure ..but so is the natural wear factor of constantly flogging the engine. I guess it could mean the difference between just throwing on a set of jugs/rings ..and doing that and a valve job too. The cleanable filters, in a race configuration anyway, are sieves ..but I guess they allow the higher CFM in a compact package. I doubt there's the room or weight allowance for a Donaldson diesel air cleaner designed for quarry duty.

The only way to make better air filtration (maybe all filtration) pay in dirt bike racing is if your competition trashes their engines so bad that they eventually can't afford to refit/refresh them.