oil cooler/mini fan

[hikertrash750]

1981 CB750C

Sitting in traffic during the summer things get hot, as you all know.

Have heard of riders installing oil coolers and adding a minifan with a manual switch.

Anyone here use them and have a kit they like?

Since buying this bike last year I have of course changed the oil out with regular oil and then and 1,000 miles ago switched to semi-synthetic and a K&N oil filter. Oil has always poured out spotless and the bike does not burn any.

The engine is spotless inside and I will be switching to full synthetic & a K&N in late spring to help with the heat issue and stress.

But thinking adding the oil cooler may be a good idea. Opinions, thoughts and anyone used kits that they like?

Thanks,
- Rick

 

[amc49]

What kit, the best solution is a CB900 or CB1100 oil cooler using the OEM bypass system that has virtually no downside at all other than you need extra parts to make one up. The OEM one does not parasite off oil pressure as it uses a separate rotor on the pump and dead ends right back in the pan. So, no pressure hardly at all to pop leaks.

You need the oil bath body specific to it and oil pan, two section oil pump, lines and of course cooler. The 1100 cooler is bigger and mounts almost the same. The other parts all come standard on CB900s of any type and bigger DOHC.

You're in Maryland, here in Texas a 750 needs a cooler as the oil pressure will drop like a rock with any hot rod driving at all. Slow down to cool oil back off and the pressure goes right back up. I had an oil pressure gauge on mine.

 

[hikertrash750]

Thanks.

So just find a 1100 and pull all the parts from it. Should bolt up.

 

[amc49]

You'll have to work out the oil cooler mounting as 750 has a place for it but no bolt holes or mounts. Easy to cobble them up though. The other parts bolt right up. 900 same parts as 1100 except for cooler itself and possibly shorter lines by a bit on the 1100 for the greater depth cooler. It's like twice as tall as the 900 one is.

 

[Motorhead]

I saw a couple of oil cooler adapters like the Derale and another one Cycle X have. They go where the OEM oil filter sits. Derale just goes under the OEM filter housing and Cycle X needs bolt-on filters like HF171.
Are they any good? It would save a lot of time and money one would spend on changing the sump, the bath and the pump.
Are there downsides to that, like oil pressure issues?

 

[amc49]

The OEM method is far more dependable, the oil pressure running through the cooler loop is then nearly nothing and reliability greatly increased since the lines are not really pressurized. The other way like many add-ons do is cooler and lines are pressurized at full engine pressure and then it also extracts a slight bit of pressure due to being in the direct feed to engine.

I thought Derale was dead, they made the proper big tube coolers needed on these, most others use too small a supply line ID.

 

[Dave]

I'm from Ca and don't comprehend this "Sitting in traffic" on your bike.

Sure, we do this in cars all the time, between the painted lines. On our bikes, we ride on the painted lines and between the sitting cars.

 

[Motorhead]

Just done.
Derale oil cooler with internal termostat which blocks off 2 rows out of 3 when the oil is not hot enough, Cycle X oil filter adapter with oil cooler outlets.
The fittings at the adapter end were pressed on lines by a local company which fits lines to heavy hydraulic equipment, my lines are of the type that is used in power steering systems and other high pressure applications.
Fittings at the cooler end are push-on type, as the cooler only has that type of flanges. It required considerable force to push the lines on. This setup should hold much more pressure than the engine will ever put out.
The asymmetrical setup at the adapter was the only way I could route the lines clear of my aftermarket headers.

 

[amc49]

Watch where the hoses are clamped at cooler for hose migration, you're at higher pressure there. I've seen lots of lines migrate at those possible pressures and nipple with only a soft single bulge to hold hose on rather than multiple hard cornered barbs all the way up. They can blow loose. I refer to the pic of cooler post #15 your other thread. Myself I use two hose clamps each fitting, ugly but no hoses blow off that way. It comes from years of clamping onto bare straight pipe like ATX cooler lines (30-40 psi) on car. I would at least tighten that single clamp up pretty close to its' limit. Fully barbed is same as multiple clamps and much stronger but costs fitting maker more money to do.

I'd be sinking that single clamp deeper into the rubber............

I wish we had places here that custom made hoses crimped, used to but they all went out of business, the legal liability thing was tearing them up for insurance. A/C hose was a lot of their business as well and EPA regulated enough that they could not stand the stress.

Watch the stat too, they have been commonly known to stick after a while and why many coolers pretty much don't use them anymore. I had a Lockhart one back in the day and after reading about all the fails I left it out of the system as it was a standalone part. Ran fine.

 

[Motorhead]

Thanks AMC, I'll try to tighten the clamps some more. There's no room to fit two clamps of that width. I got the clamps at the same hydraulic shop, supposed to be of better quality.
The hose has some thermal insulation material, as you can probably see in the middle pic. This stuff is VERY hard. It literally took two men (me and a friend) to push the hoses on, one holding the cooler, the other pushing and twisting the hose with both hands.

Of course, I'll watch the hose for migration, thanks for pointing that out.

The thermostat is an internal bi-metallic plate, it sits inside the right vertical cooler tube, permanently fixed to it's top. Don't think it can be removed without damaging the cooler.