Well, you can buy damper oil if you like (Penrite make a lever arm damper
oil in a 1 litre bottle). Moss sells damper oil too I believe.
Do not use ordinary engine oil. Firstly, it will be the wrong viscosity
you want a straight 30 weight oil, not a multigrade oil. If the viscosity is
too high, the dampers will develop leaks and may even split. Secondly,
engine oil will froth and foam when used in the damper and render your
dampers effectively useless!
Damper oil, motorcycle fork oil (available from m/cycle stores in weights
from 5 to 40) both have the right additives to prevent foaming. They are also
stable under high temperature.
Probably the easiest is to use Auto Transmission Fluid (ATF). It has the
same properties as damper oil and is approximately the correct weight. I
have used it successfully on my race spridget.
Interestingly, just on the weekend I did a side-by-side comparison of
penrite damper oil and ATF. ATF was a little stiffer but the damper oil was
held it behaviour just a tiny bit better. I'd say the damper oil has more
anti-foaming additives. I'm sticking with ATF because I like the slightly
higher damping.
Mike
_______________________________________________________
Mike Gigante mg@mega.cgl.rmit.edu.au
3D interactive graphics, british sports cars, and wine
http://mega.cgl.rmit.edu.au/~mg/
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