Message text written by "Roger Anderson"
>Further to the previous correspondence regarding the oil pipe from the
banjo at the bottom of a Rotax engine to the reservoir, I have recently
experienced a failure of this pipe. I had routed it under the forward
coolant pipe and over the rear one, but following the advice given recently
by Andy Draper to this forum in respect of 914 engines, I decided that even
though I have a 912 I would re-route the pipe over both coolant pipes while
doing the annual check.The pipe failed close to the banjo shortly after
completion of the check. On removal from the engine it was apparent that
the pipe had taken on permanent bends, and subsequently when flexing the
pipe crackling noises could be heard as if the bond between the rubber and
the reinforcement was failing under stress. The pipe was the red stripe
variety, originally supplied by Europa. I understand that they are now
supplying a superior quality pipe, but if you have the red stripe variety,
be warned!
If I had let well alone I suspect that this pipe would have continued to
function satisfactorily - but who knows for how long?
The lessons appear to be that the red stripe pipe does deteriorate in use
(mine had done just over 70 hours flying), and that if you decide to
re-route this pipe it is probably prudent to replace it.
Safe flying to one and all.<
Having replaced my return pipe with a lined silicone pipe, which can stand
temperatures of 300 deg C (approx twice that of the rubber variety) I would
recommend it to others although my Europa has yet to fly so it has not been
proven. It has spiral steel reinforcing so it will not kink whilst being
able to follow all the necessary curves. As it is so tolerant of heat it
may not need such a convoluted route back to the oil tank. My Europa is a
'Classic' with the oil tank on the port side and I will be trying mine out
by routeing it straight across under the oil tank and up behind the curved
portion of its mounting bracket. This gets it away from the hot area fairly
expeditiously whilst simplifying the routeing. I used short lengths of
heatshrink at each end to protect the relatively soft surface of the pipe
against the compression of the Jubilee clips. My inspector thinks that it
should not be necessary to use firesleeve given the specification of this
pipe. This should ease inspections during oil changes. With the existing
rubber pipe with firesleeve inspection means removing the upper pipe
fitting and then the firesleeve which is not easy. The length of hose was
not cheap (35) but it should give better service. It is available through
specialist performance automobile suppliers and as it is being used for oil
it should be the variety with the appropriate inner lining.
Nigel Charles
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