Dear All,
On the subject of oil pressures, it might be worth me
recounting a
problem I had a few years ago with my TR4A. The engine at this time was
worn
but still servicable normally giving about 50psi oil pressure when hot at
2000rpm.
One morning I went to start it and it just didn't want know. It
would
churn over fast enough but just wouldn't fire. The previous evening it
was
running fine, in fact I'd just filled it with petrol in preparation for
the
next day. After much persistance I managed to get it to splutter over
very
roughly, with full throttle and no choke, but to my horror even at
3000rpm it
could only manage about 15psi oil pressure!!
In desperation I checked the oil level and there was plenty there,
in fact rather more than there should be!
I was totally baffled and horrified by all this, and was beginning
to
think that maybe I should take up a simpler hobby like gardening instead,
until it dawned on me what had happened.
On the 4A the top of the petrol tank is higher than the carburetter
float chambers (with Strombergs anyway). Consequently if a needle valve
jams open the float chamber fills under the influence of gravity, petrol
then runs up the jet, down the manifold through the valves past the rings
and into the sump. I had been try to start it with a sump half full of
petrol!!
After cleaning the carbs and changing the oil all was well again,
much to my relief!
Keith Bennett.
CTC57462 O, GA225787CV, GD1409RS
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