Just got the following email in response to comments on poor cold starting in Kubota article:-
"I was an R&D engineer with Rolls Royce working on Diesel engines for mostof my working life which involved quite a lot of cold starting work down to as low as minus 40C. During the severe winter of early 1963 we had several engines lined up in an open shed for cold starting tests mainly using ether. When the engines fired on the ether the detonation had to be heard to be believed, it sounded like someone striking the piston with a very large sledge hammer so I can understand the warnings about the possible consequences of its use. Later on when working on an military engine which had to start down to minus 40C we had a failure to start in a cold chamber test and when this happened we had to start the engine by hook or by crook to clear the engine out or the next test would not be representative. This engine had a large diesel burner in the intake which had failed to ignite so the next attempt was for me to spray two aerosols of starting fluid into the intake whilst my colleague pressed the starter button, it was an 18 litre V8 so it needed a lot, nothing happened for a few seconds until the burner igniter lit the ether leaving me holding two aerosols which looked like flame throwers with flames right back to the nozzles, needless to say I very quickly released the nozzles. The interesting part of all this was that the engine did not respond to the ether alone but fired immediately when the ether ignited demonstrating that the best cold starting aid is heat as we confirmed later when the burner worked properly."
"I was an R&D engineer with Rolls Royce working on Diesel engines for most