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Not only that, modern engines are constructed to closer tolerances, operate at higher RPMs, higher compression ratios, and run on much leaner fuel-air mixtures.

All these things compound the damage done by a faulty cooling system.

Now, in the event of a faulty lubrication system, things are even worse since engines are designed to operate with higher lubricant pressures and thinner lubricant and less lube in the oil pan. With a higher oil pressure, the bearing areas are reduced to minimize rotating and reciprocating mass and friction losses. Take away the oil pressure and things really go to sh1t fast.

Gone are the days when an engine run out of oil would simply seize up, then free up once cooled off and be good to go simply by pouring some oil into the crankcase.

It used to be that a motor might have some knocking or ticking or sounds or wear and a careful owner could milk quite a few more years of use out of it. Nowdays, once you start to hear a little bit of valvetrain noise, the motor is very near it’s final days.

And to make matters worst, the oil companies have been changing the formulas for their lubricating oils, making for "high mileage oils" which are designed to have even higher viscosities in thinner films. But if you get into a situation where there's a higher load, those thin films break down VERY quickly and easily, leaving you without lubrication.

This is why you should NEVER use automotive oil in motorcycles any more, especially if the bike shares the crankcase and transmission, or has a wet clutch.

Mark