Oil cooler + or -?

What is the lastest on oil coolers they seem like a good idea to keep the engine cool, but if your sitting in traffic there's no airflow so are they worth it or what?

you don't mention what your bike is, and what (if any) modifications are done to it. How you ride and where you ride impact the answer as well.

In some climates, they can cool too much. Even those with a thermastat built in may need to be covered when riding in cold weather. If you take short trips the engine will not come to full operating temperature, resulting in condensation inside the engine.

Oil coolers can reduce the effective oil pressure at the engine. The oil pump has to pump the oil to the cooler and back to the engine before oil reaches the top of the engine.

If you are running in a warmer climate, or with an engine with high compression pistons, the cooler can help. I don't like to see them put on a bike UNLESS there is a real reason for them. Too many get added as they look neat - but that's the wrong reason.

downhandonly wrote:

What is the lastest on oil coolers they seem like a good idea to keep the engine cool, but if your sitting in traffic there's no airflow so are they worth it or what?

They will still have some effect even without airflow, although they will work better with airflow. Running the oil outside he engine through the cooler (radiator) is going to cool the oil even without forced airflow.

I think they are worth it if you live in a warm climate. They are less essential now that synthetic oils are available since they don't fall apart at heat like conventional oils.

I've lived in warm parts of the US and have run oil temp gauges on my modified Zs. From personal experience, my Zs need oil coolers w/thermostats - oil thermostats are a must. Even here in Central Florida, a long winter Sunday ride 'in the country' might only raise oil temp to 155-160 degrees F and that's with a Lockhart DP-180 thermostat that opens partially at 160 degrees F and is fully open at 180 degrees F. But most of the year around here, I'll get oil temp up to 180 degrees in just 4 to 5 miles of city riding/commuting. I like to keep my bikes’ oil temp between 180-210 degrees F.

I've seen oil temps on my '73 Z1 of over 250 degrees F while in stop-and-go traffic - the motor is a mildly modified. On a cold evening during Bike Week in Daytona Beach last March, while stuck in heavy stop-and-go traffic (mostly stop), I saw oil temp of 220-plus degrees on the Z1 of mine.

If you really want to know if you need an oil cooler, install an oil temp gauge.

Ok I'm game for that. I'm handy with a drill and tap so where do I start?

What year and model?

Different bikes have different setups and engine fittings for attaching the new oil lines between the engine and oil cooler.

BohicaBob wrote:

oil thermostats are a must. Even here in Central Florida, a long winter Sunday ride 'in the country' might only raise oil temp to 155-160 degrees F and that's with a Lockhart DP-180 thermostat that opens partially at 160 degrees F and is fully open at 180 degrees F.

Hey Bob, How does the oil thermostat work? Does it restrict oil flow...seems that would be dangerous. Or does it somehow divert it around the cooler?

Most thermostatic bypasses are an intregal part of the cooler. The coolers have 4 or 5 rails to cool the oil. The thermostat routes the oil through the top rail only and therefore reduces the cooling effect on the oil.

I have seen some other approaches to bypassing the cooler - where the oil takeoff at the engine has a manual bypass valve going past the oil cooler entirely.

Thanks Jeff!

Had a lockhart inline thermostat on a 900 it just bypassed back to the engine until it reached operating temp. then diverted flow thru the cooler.i presently have a z1 cooler with no thermostat and 1 inch oil lines but i havent ridden it enought to see how its going to work.it does make enough oil pressure to kill the idiot light.

1980 kz1000 ltd

On my M2, after I intalled the 1135 10.25 Wiseco pistons, I decided to intall an oil cooler from an '84 GPZ1100. I'm assuming that stock cooler does not have an internal thermostat, but I don't know.

I live and ride in Oregon where the weather rarely gets very hot.

Now, reading this thread, I'm wondering if I shouldn't have installed the cooler. I guess the only way to know for sure is to get a temp gauge and see how hot the oil gets.