On 02/03/2012 03:45 PM, John Wighton wrote:
> The LAA instructor used to work at Rotax, so l sort of assumed he knows best.
I guess the people who wrote the operators manual also work for Rotax
and also knows best.
> I don't think oil gets spurted up around the engine when it is hand cranked -
does anyone know the answer?
I do. The oil gets there. The oil pump doesn't know who is turning the
engine, so it dutyfully starts pumping oil as soon as its shaft starts
turning.
I somehow get the feeling that you don't believe me on my word. So here
are two tests you can do to convince yourself:
1) Get an assistant to hand crank the engine. Switch on the engine
instruments (NOT the ignition!) and observe the oil pressure gauge when
your assistant cranks the engine.
2) Disconnect the hose from the sump to the tank. Some oil will drain
---From the engine. Wait until it sort off finishes draining. Then hand
crank the engine. New oil will arrive soon in the sump. You can repeat
this many times; every time you crank the engine some new oil will come out.
And finally, ask an expert why it is bad to hand crank the engine in the
wrong direction. He will tell you that the oil pump now pumps the oil
out of the system and air will enter it. Hence the oil pump is working
while hand cranking.
Frans
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