This page is about the deep oil pan for the /2, but most of it applies to the /5
and later bikes. Several types of accessory oil pan products have been
offered. I think that I have seen, or heard about, at least 6 types of
accessory pan for the BMW motorcycle.
One had deeper fins for more cooling and was cast out of aluminum. The
idea was to improve the cooling of the existing quantity of oil, not increase
the air volume.
Another type was a spacer. It used the stock oil pan as the bottom.
It "sandwiched" a cast aluminum spacer in between the block and the stock pan.
It also used a spacer to lower the pick up. The bolts that hold it on can
come loose and fall into the pan. It was supposed to have a sheet metal
retainer that could be folded up against the bolts to keep them in place.
It required two gaskets on the pan and two gaskets on the oil pick up.
This one held more oil, but didn't increase the cooling significantly.
Since it didn't come with a longer dip stick, one just kept the same level.
At least one more pan had a few air tubes running lengthwise through it for
air to flow through. It held more oil and cooled it a bit better.
One pan is reported to have the oil drain in the front. One seems to
not have spring mounts for the stand. Another one is reported to be of
very low quality.
The two possible reasons for using a deep sump are both "slightly" valid.
On the /2 and /5 they were to help cool a "perceived" hot engine. In a
very few cases it may have been necessary, some of which it was the wrong way to
cool, another story. While the /2 suffered some
piston over heating, the oil was never an
issue. I have ridden the R60/2 (certainly the worst one for heat) across
Death Valley in the middle of August in the afternoon. The only
thermometer I saw said it was 125 F. and I believe it. Yes, I was
stupid. Neither the bike or I had trouble with overheating.
With the advent of the 900 cc engine and the resulting leaks and noises, some
figured that the easy way to increase the air volume is to drop the oil level.
After all, a piston engine is almost the same thing as an air compressor.
Actually quite smart. That drops the peak air pressure that is caused by
the large 900 cc pistons coming to BDC. The high pressure causes oil to go
past the seal and generally leak from many places. It reduces the peak
negative pressure caused by the pistons going to TDC. Any air escaping or
being pulled in past the seal, can and does make some very odd noises. Air
getting sucked into the engine crankcase is the real problem. This greater
amount of air gets compressed to a higher peak and the official breather can't
handle it. The solution was to develop a rear main seal that didn't allow
air to get sucked into the crankcase.
Some add an oil temperature gauge to the motorcycle. More than one
accessory pan had a provision for a temp sensor. That is fine if you are
the type of person that simply "needs" instrumentation. It is for looks,
but it isn't for any need. You only add another place for oil to leak and
cause trouble for normal maintenance. These bikes just don't get the oil
hot under any kind of normal conditions. I have ridden a R60/2 across
Death Valley in August. Yes, I know...stupid. That model was prone
to overheating and I just didn't worry about it. Relax and ride.
Conclusion, Don't waste your money
Stripped pan bolts
The pan bolts are easily stripped out of the threads in the crankcase.
It is easy to think that they must be tight so that they don't fall out. I
am sure that it is possible for one to fall out. That would be really bad,
depending on the model, as all of the oil would run out very quickly. I
have never seen this happen. What does happen is that owners over tighten
the bolts and strip out the threads and don't know it. Then it leaks.
The bolts only need to be tightened up a very small amount. There is a
variety of types of gasket material available. The /2 used a cork gasket.
That one was a bit difficult because the gasket would shrink and leak. It
needed to be tightened up soon after use. That pan is made of sheet metal
and would easily warp. Over tightening easily warps it and then it leaks.
Use your favorite sealer on the gasket and bolts. Oil can run down the
threads of the bolts. Then gently tighten up the bolts. Then check
them often at first.
I understand that silicone gaskets are now available and they seal well.
One choice of pan for the /2. Photo from Jim, thanks
One email I received.
Hi Duane, I got the new pan from S. Meyer in Germany and cost $78 Euro
plus $29 Euro Postage to Australia. It has the pick-up extension and the
lug for the side stand spring( although it is not drilled). It has a row
of small cooling fins along the bottom , has the drain hole at the rear and
comes with stainless cap screws to mount it. I am not sure of the
volume...I THINK it is 2.5 Liters. With the pick-up extension installed,
the screen is only a couple of 'mm' above the bottom of the pan. It is
very nicely made and almost matches the crankcase in color and texture.
If I get good photos of other types of pans and information, I will post them
here. Send the .jpg to me and title it "deep oil pan".