Topic: Oil cooler factory type any good?

[Dunk]

Do the factory type oil coolers that go behind the filter housing make an appreciable difference? I've been surprised at how high head temp gets in middle of summer in 100* heat, wondering if it's worth installing one of these and maybe finned tappet covers. Not sure it would be good in winter down to single digits or teens, takes a long time to get temp in the engine that time of year but this type and finned tappet covers could be quickly added/removed between seasons.

https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_21_250_62&products_id=4559

[pickleknuckles]

Do the factory type oil coolers that go behind the filter housing make an appreciable difference? I've been surprised at how high head temp gets in middle of summer in 100* heat, wondering if it's worth installing one of these and maybe finned tappet covers. Not sure it would be good in winter down to single digits or teens, takes a long time to get temp in the engine that time of year but this type and finned tappet covers could be quickly added/removed between seasons.

https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_21_250_62&products_id=4559

I've got the Yamiya cooler on my K4. Not sure how much it helps but they worked well enough for Honda to put them on all the SOHC F series bikes.

I think the tappet covers were a style thing rather than actually functional.


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[newday777]

I don't know the stats of an appreciable difference of the passive cooler from the F2, it should help while moving more than 45-50 mph for better cooling in the high heat.
An actual oil cooler like Lockhart put out in the 70s, with a thermostat valve, would probably be a better choice for cooling the oil, the thermostat valve will help with cold weather heat building.

[Deltarider]

Your bike has been designed to run well in all temperatures. Although they relate, head temp is not the same as oil temp. When you suspect overheating of the oil, the usual remedy is to shift down a gear and increase revs and so increase oil flow. I wouldn't fit anything until a measurement tells me it is really needed. An oil temp gauge could be a good investment, but not anyone wants to change the looks of his bike. In the past I've pleaded for the development of a simple small three led idiot light which is small enough to tuck away between the odo- and tachometer. It's modest, intuitive and - last but not least - can be monitored from the corner of your eyes. I would suggest three color codes: blue = oil has not really warmed up yet, orange = approaching limit, red = too hot. Extinct would indicate oil temp is at working temperature, meaning not too hot, not too cold. Here lies a challenge for the engineers in our forum. That is: if there are any.

[M 750K6]

I'd rather their time was spent working out how to change a primary chain and tensioner without removing the engine!

[PeWe]

A good oil. Motorcycle oil 20W-50.
A synthetic has longer life in high temperatures.
I'm sure Spectro Heavy Duty mineral will work fine too. Developed for long stroke hot running engines where the oil film must work during a long stroke and higher temp.
CB750 with 63 mm vs HD and similar with >100mm stroke.

Start with a temp gauge to see what temp you'll get.
https://www.yamiya750.com/index.php?main_page=product_info&products_id=1484

This has helped me to verify the oil temp. I have seen 120*C (248F) where red area starts. No problem. I tested mine in boiling water, spot on 100*C.

To translate C to F:
https://www.metric-conversions.org/temperature/celsius-to-fahrenheit.htm

Diesel oils not developed for air cooled engines, too hot. Oil that crash will not only lubricate really bad, sludge can be produced.

There is a thread about it in the open forum with youtube link.


Over 100*C is good, condense (water) will leave thru the breathers.
A thermostat that connect the cooler AFTER 100*C on a street bike is my conclusion.

[bryanj]

PeWe, ever heard of Deutz diesel truck engines, air cooled high hp and using standard engine oils, if the oil is the correct se rating and grade its fine, plus frequently still has the zinc etc that new car oils dont have

[Dunk]

Diesel oils not developed for air cooled engines, too hot. Oil that crash will not only lubricate really bad, sludge can be produced.

There is a thread about it in the open forum with youtube link.

Interesting. I have been using Rotella T6 diesel oil in my bikes for at least a decade. It's easier to just stock one oil for everything, it's JASO rated and never noticed an issue in CB750s, CB350 with all the old roller bearings and mediocre old style oil pump, XL350/600 RFVS engines that tend to run really hot. Always thought I was doing good by running synthetic in hopes it would not break down as quick in high temps. I've never noticed any sludge buildup, not like what I've scooped and flushed from a few CB750 oil tanks over the years that were probably never cleaned by previous owners.

Over 100*C is good, condense (water) will leave thru the breathers.
A thermostat that connect the cooler AFTER 100*C on a street bike is my conclusion.

Indeed a cooler with thermostatic bypass valve would be ideal. As it is in winter my oil cap looks like this every time I check. Granted it seems to just be the vapor condensing on the cold cap when below freezing, the oil itself looks fine.