23-01-2021, 12:00 AM
Yes I've seen a 4-stroke diesel running backwards too. Doesn't run very well, because injection timing is slightly the wrong side of top dead centre, but run it will, sucking air through exhaust and blowing exhaust via air intake 
Petrol 2-strokes are often capable of running backwards, but not 4-strokes, because there's no carburettor on the exhaust side, to introduce fuel...
Surprised it damaged the head gasket though. I can see the valves not liking it, with the inlet valve having to cope with hot exhaust, and the oil pump running backwards isn't going to send oil around the engine, but would be interested to know why the gasket failed.
Petrol 2-strokes are often capable of running backwards, but not 4-strokes, because there's no carburettor on the exhaust side, to introduce fuel...
Surprised it damaged the head gasket though. I can see the valves not liking it, with the inlet valve having to cope with hot exhaust, and the oil pump running backwards isn't going to send oil around the engine, but would be interested to know why the gasket failed.
