Hi everyone,

I need help looking for adapters to attach an external oil cooler to a 1991 GS 500 modell. Some guys and I in Germany are trying to tune the GS500 motor and we are having problems with the oil temperature.

There used to be adapter sets on sale here, that replace the oil filter lid, but they cannot be bought here anymore. I was thus wondering if anyone knows of any sources / systems / tricks to easily attach and external oil cooler to an old 1991 GS motor.

I'd am really greatful for any helpful input that you can provide and thank you in advance...

Best regards,
Herby

The 2004-present GS500F model, with fairing, has an oil cooler attached.  Perhaps you could adapt one to fit your '91 motor?

I think it was discussed recently that the passageways under the pan aren't the same on the '01+ models

There is internal plumbing cast into the 04+ cases. It will not fit without additional internal modifications, I do not know exactly what those mods are yet.

Put a big fan in front of it.

hes talking about an adapter that you place in the oil filter spot, so there would be no need for extra plumbing. but i have no clue if something like that actually exists.

Quote from: CndnMax on July 31, 2007, 03:40:25 PM
hes talking about an adapter that you place in the oil filter spot, so there would be no need for extra plumbing. but i have no clue if something like that actually exists.

I thought about this because it gets very hot and humid where I live.Only thing is you'll get a drop in flow and pressure along with unfiltered oil going through the engine.Well,that is if we are thinking alike.

I don't know which direction the oil flows through the filter.  If it's inside-to-outside, then the cover should have pressurized filtered oil right there.

I dont know ! but I have been checkout motor that have oil cooler I notice that the 2 lines for the oil cooler came from the cranck cover  I think you have to change the crank cover and put on the oil cooler lines in the new cover .

crank cover must be for oil cooler GS engine.

oil flows through the filter outside to inside. if you look at the filter, the thing on the top is a pressure releif valve, if the pressure on the outside is too high, it bypasses the filter by pressing in the black thing. so the casing is pressurized.

I would imagine you could drill/tap the center of the oil filter cover for a pipe fitting or a banjo bolt, and dump the cooled oil back in the crankcase. Anywhere, really would be good, but ideally, you would be dumping reasonably close to the pickup, so it could get filtered.

you could use a longer drain plug turned into a banjo bolt for a return as well.

there is also a service tap on the RH side of the engine, near the front next to the signal generator. you could banjo-bolt that for your feed to the cooler. I beleive that line is also pre-filter.

one of the most important things you may have to do is have some way of regulating flow to the cooler - you don't want the oil getting too cold, and you want to make sure you're cooling all of it (if the return is real close to the inlet, you may end up cooling a portion of the oil, and slowly cooling the rest). what i'm saying is you need an inline thermostat that will also act as a restrictor.

if you guys are dyno-tuning, once you get this set up, tap in some thermocouples and take a look at the oil temps. then post your findings here