Air Cooled Hot Rod: Huge Oil Capacity Means No Need For an Oil Cooler?

[nicholastanguma]

For instance, say you've got a hot rodded 350cc air cooled single with big cooling fins and enough oil capacity in the wet sump for an engine size of 550cc - 600cc; would you still need an oil cooler?

[Truckedup]

You mean an Italian single? It all depends on the engine and ambient temperatures.

[RDY4WAR]

As someone who's passion is oil and lubrication, I'd want a cooler anyway.

[emsvitil]

My Sportster doesn't have an oil cooler.

Dry sump system.

The oil filter and oil tank would have some cooling capacity.

Don't know if having roller bearings makes a difference though.

[PackardV8]

More oil capacity just means it will take longer for the oil to reach the same temperature.

Oil temperature is load dependent. Install a cylinder head temperature guage and an oil temp gauge. The head temp will jump up almost immediately, but the engine has to hold a steady load for the oil temp to get up to operating temperature. More oil, longer time.

Then, put the ride on the road at above 50% load; the greater the load, the quicker the results, and hold it there. Usually, without an oil cooler, the oil temp will gradually continue to climb, as the load is adding temperature faster than the circulation and reservoir can shed it.

[nicholastanguma]

More oil capacity just means it will take longer for the oil to reach the same temperature.

Oil temperature is load dependent. Install a cylinder head temperature guage and an oil temp gauge. The head temp will jump up almost immediately, but the engine has to hold a steady load for the oil temp to get up to operating temperature. More oil, longer time.

Then, put the ride on the road at above 50% load; the greater the load, the quicker the results, and hold it there. Usually, without an oil cooler, the oil temp will gradually continue to climb, as the load is adding temperature faster than the circulation and reservoir can shed it.

Very helpful, thank you.

[pcnsd]

What is your application? Long or short time duration? Cruising or racing? It really depends on what your doing. I don't run an oil cooler on my single, have raced at 108F, but my races are over in under 4 minutes typically. Coolers add weight and are one more thing to damage if you crash. Races longer than 10-15 minutes or fast cruising in desert climes... I think a cooler starts to make sense.

[nicholastanguma]

What is your application? Long or short time duration? Cruising or racing? It really depends on what your doing. I don't run an oil cooler on my single, have raced at 108F, but my races are over in under 4 minutes typically. Coolers add weight and are one more thing to damage if you crash. Races longer than 10-15 minutes or fast cruising in desert climes... I think a cooler starts to make sense.

Also helpful, thank you.