diesel engines

In regard to ether - it depends how you use it, and how much you use, and on the design of the engine. With some engines - you can easily ruin them fast. Deere diesels with square-cut rings - instead of Keystone are a good example - e.g. as used in 350 crawlers, 1020 ag. tractors, early 450 crawlers, etc. Those top rings and pistons shatter pretty easy when hit with a lot of ether. When Deere puts factory installed ether injection on an engine - manual or electric- a control orifice is used to prevent how much ether you can jam in at one time. But, when spraying directly into an intake or air-cleaner, there is no control. In our shop - we did more engine repair work from cold-weather ether starting - then from normal wear. Farm tractors were rarely a problem since they usually had block heaters. Big problem was with crawlers and log skidders sitting in the woods a 20 below zero.