Oil coolers..why on some models and not others?

[Sunbeem]

Who's nicked me bloody oil cooler ???

Sunbeem '78 RS.

[dougie]

You could have a summer bolt, a winter bolt, and a spring/fall bolt.

That would work well Doug, but I'd need the winter bolt for early summer days, followed by the spring bolt by about morning tea time, and then the summer bolt about lunch time.
Unless of course the day was going to be a scorcher, then I would have the summer bolt in by breakfast time.

Maybe you could make something like a long throttle stop screw with a cable ....................................
Nevermind then.
I need more beer.

[ME 109]

Who's nicked me bloody oil cooler ???

Sunbeem '78 RS.

I thought UK RS's had oil heaters?

[dougie]

Who's nicked me bloody oil cooler ???
Sunbeem '78 RS.

I thought UK RS's had oil heaters?

Nah. That's us Jeff.

[Indian]

I connected an oil cooler in series with the heat exchanger in my car. The termostat opens at 84 degrees. Temperatures used to be as high as 130 degrees. Now its at 100 max.

[moosehead]

Want to make correction to my earlier post, my 82 RS has the thermostat oil filler cover..it was my RT that I went to the GS (non thermostat cover) on. That bike is long gone.

I just returned from 3 day ride on the 82 RS. I have a oil temp guage and oil pressure guage (both electric VDO's with sending units) 2 guages in middle of instrument cluster. Temp guage never gets above 180F even on hotter days and riding 120kmh+ (4 lane slab running). Usually runs around 140 to 160F. Oil pressure around 70 as oil temps heat up (as best I can tell from the guage) At idle and oil heated up, pressure will drop down to about around 40-50psi. which is normal I guess. Only time the oil temp reads over 180F is when in stop and go traffic or slow running in hot weather.

Now have a 77 RS without oil cooler...so would it be worthwhile to add oil cooler (and thermostat oil fill cover) or just go with stock?? Just wondering if worth the effort? I'd like to keep this bike for touring and sell the 82RS. Did BMW engineers decide after having produced the fully faired 77 RS that they figured that the subsequent model year RS's would benefit from oil coolers?

[Roy Gavin]

The 77 bikes had a shallow sump , so a second hand deep sump is a cheap improvement.
Anton Larbidgers site has all the details on sumps and dipsticks..

Mac deep sumps are still around too - Niche Marketing? sells them on Ebay for around $80-.

My G/S has a sump spacer which seems to work quite well, but I dont like the look of them and they are quite expensive- you may as well go the bit more and get a cooler.

Oil doesn't flow like water. as the viscosity changes a lot more with temperature, so a vertical oil cooler like BMW uses is pretty much self regulating without a thermostat - there is a good temperature grades photograph around somewhere which shows just why.

[ME 109]

Anyone know at what oil temp a thermostat should begin to allow flow to the cooler?
Regarding deep sumps, I can't see how an extra litre or so would reduce oil temps on a long ride on a hot Aussie day?

[vanzen]

Anyone know at what oil temp a thermostat should begin to allow flow to the cooler?
Regarding deep sumps, I can't see how an extra litre or so would reduce oil temps on a long ride on a hot Aussie day?

I was told, long ago, by a competent source (factory mechanic and BMW racer)
that the best use of an after-market deep sump
was NOT to add the additional liter of oil –
but to run a liter low
as a method to reduce crankcase pressures at higher revs ...

An RS + hot aussie days = a good reason for a cooler !

[ME 109]

Yeah I recall being informed as to using a deep sump for the benefits of lower crank case pressure.
I've just replaced barrel base o ring and head gasket on the left side, she was blowin' out the base at sustained high revs. All over my boot.
I think Roy was talking in terms of increased oil capacity to aid cooling?
I've often thought of finding a 'louvered' lower centre fairing piece instead of my '81 solid piece. It would possibly provide as much cooling as an oil cooler?