Water Cooled vs Oiled Cooled

Is Oiled cooled engines have similar life expectancy as water cooled engines.

Know any draw backs to oil cooled engines.

Just doing some research for my son who is looking at purchasing a Ducati when he returns from his Deployment.

Water cooled engines have a long life due to the closer tolerances in the engine compared to air or oil cooled engines. I do believe that if the Venture 4 cyl. engine was air/oil cooled, there wouldnt be as many on the road with the high mileages that get put on them.

Air/oil cooled engines run hotter and for every 20° increase in temperature, your oil will degrade faster, additives will burn off faster and you loose protection. So a water cooled engines should theoretically last longer just on that point alone. They maintain a more even temp during operation also.

Plenty of old oil head BMWs with high mileage still on the road. Just about any bike built today (in a first world country) will last if taken care of. I could expect a Duc would outlast his fascination with a sexy sportbike.

RR

Hot and cold equals expansion and contraction. All engines start out cold and then get up to operating temperatures. A water cooled engines temperature variations are very minimal due to the thermastat radiator and constant cirulation of coolant. On extremely cold days it takes longer to reach "operating temperature" and on extremely hot days it takes very little time to reach "operating temperature". An air-oil cooled engine has a much larger variation in temperatures greatly impacted by the climate. On cold days they run cold and on hot days they run hot. Oil coolers do a great job to keep oil/air cooled engine from getting over heated. That is the primary reason why water cooled engines last longer than air/oil cooled engines. Hope that helps some.

I would say quality of manufacturing would have as much to do with it as water cooled vs oil/air cooled. The Venture (water cooled) and the Road Star (air cooled) will both go well over 100k miles and I've heard of just as many of one as the other over 150k miles.

Water cooling is more efficient. Large changes in oil temperature equate to changes in oil viscosity and lubrication. The engine must be designed to handle this. With todays leaner mixtures, emissions and fuel injection, it just makes me wonder how much further they can push the air cooled envelope.

Mike