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After a long rest and resurrection, my R80 did fine in the heat and the cold. Many miles at redline and a few tires passed away. Then, in the heat of summer, I pulled out a hinged BMW filter and half of it was collapsed to the point of almost having the paper part of the filter going through the gap in the perferated sleeve inside. I wrote it off as a bad filter and hoped. A straight K&N went in and it came out oval. Another K&N went in and I babied the thing for 1500 miles and that one came out oval. They are flattened completely in the middle.
Same brand/weight of oil as always. The oil does not look particularly dirty. The filters don't either.
I have looked around and searched but came up with nothing in the way of an explanation.
What would cause this to suddenly occur? I really hope one of you folks has an answer 'cause this bike likes to go and I like to make it go.
'85 R80.

Where do you live, (ambient temps) and what weight oil are you using?
I will only use a OEM or Mahle, which is the source for OEM. This will not guarantee that you won't see a crushed filter, though.
Do you warm up the bike a little before taking off? Cold oil=HIGH oil pressure.

And during those "Many miles at redline and a few tires passed away", how many times did you change the oil/filter?

I think racers change their fluids & filters after every race.

Same 20-50 oil as every summer before. 90 degree temps. Warmed up. Oil and filter changed at sane intervals.
The sleeve inside the BMW filters (all it ever had in it) does not overlap. The K&N's did, otherwise they would be inside the block now. There is a BMW filter in there now. I hope it is all together and in the right place.
It is useless as it is. Even babied around town the problem is there. I had hoped someone would have run into this before (not wishing ill luck, though) and know of anything other than a clogged filter that would cause three in a row to collapse. It never did before, winter or summer.

Have you checked that the bypass valve is working correctly, and also that you are not getting petrol or dust into the oil somehow.

K & N claim higher flow than stock, and also to remove finer particles, so fine dust from a air filtration or breather malfunction could be a problem.

Some of he racers which ran at high rervs claimed to have a slimmed down oil pump - they are reputed to flow more than is needed at high revs.

But iI wouldnt discount this being malinformation put out by a team manager so his opposition cooked their motor - some of thay junk went on to be accepted fact.

Like the two piece push rods---------.

This is not new, as we often found the filters smashed back in the 70s. Some brands were worse than others. Don't ask which.

Three filters and two different brands almost eliminates the filter as the cause.
As Roy said, the oil filter bypass would be a suspect.
It would be difficult for the ball in the filter bypass to completely block the bypass hole, unless all the spring was gone.

A blockage in the oil gallery before the front bearing web?
Oil pressure relief valve?


Usual disclaimers......

I'm sure my engine would be even unhappier with a big wad of paper filter being pushed through it. As a bizzare potential preventative measure, before I put the latest filter in, I swapped out the oil intake pipe. I used one of the long pipes meant for an oil cooler, shortened it to fit under my cover, left a gap between the end of it and the cover and crossdrilled the thing. It would be hard for a filter to flatten enough to come apart as it is now.
I did check the detent ball for sure. I do read here and y'all usually get around to answering my questions without me having to ask.
Dust should not be a problem. It is sealed up good. I did wonder about the crankcase breather and what the effect of it failing would be.
Y'all know how this goes already. We hope for an easy answer before digging in randomly.
If any of you notice a nasty black stripe from a locked up engine/sliding back tire on I-85 and see Matt parting out a Mono R80 less engine with severe post-mortem damage from a 3lb hammer...you will know how it went.

Are you using the right sized filter? There's one for coolers (shorter I believe) and one for non-coolers. I could see that a longer one in the cavity where the shorter is needed might tend to put some extra "crush" factor on the filter. But if the filter was the wrong size and longer, it would be very difficult to install the outside cover.

Kurt in S.A.

Wow! when it rains it pours!

I pulled a similatry collapsed filter (first time I'd ever seen one) out of a r65LS this week.
I figured the last installer crushed it on the exhaust pipe while installing it.

hmmmmm.....

They are the right size filters. I'm too lazy to wrench one in there when I can put the bolts in most of the way with fingers. There is a serious temptation to use the reusable stainless mesh filters and just ride the thing. I'll try different oil (not going into the brand wars here!) next time.
This is one of those things that makes no real sense. No obvious change in variables and how much oil pressure would it take to squeeze a perferated aluminum tube flat if the filter flows at all. Air flows through them even soaked in oil fairly easily.