BY – BRIAN WINCH.
Review of modelling products conducted by the AIRBORNE ENGIN-EAR.
COOLPOWER MULTI-VISCOSITY OIL –
PURPLE – THE ROYAL COLOUR.
What is purple and goes ‘glurk, glurk, glurk’? Stand up the boy who said ‘a purple chook when
you are holding it by the neck’! The correct answer is the new Coolpower Multi Viscosity
PURPLE oil. Even if you’re not into engineering and lubrication in a big way you would
understand that oil has a drag factor. Going to extremes, an oil as thick as honey is going to be
harder to spread around than the oil you put on the skin of a baby. The effect is call ‘lubricity
drag’ – a fluid friction that increases as the viscosity of the oil goes up the scale. Shock, horror
again here for the ‘castor brigade’ but the fact it that castor is high on the scale. There is a usage
level with the type of oil and its viscosity whereby, if exceeded, the drag actually robs power
from your engine.
Consider the oil used for full size car engines. Years back an engine in good condition would
use 30 weight oil in winter and 50 weight in summer. Some of the high performance chasers
used 20 weight oil but, in those days, it was way behind the technology of today and, quite
often, the engine suffered badly. In our model engines with the oil as part of the fuel mix, fluid
friction with the moderate to heavy oils comes in above around 16% lubrication. Now some
eyelid fluttering smartass is going to give me a jab by bringing up pylon engines. In pylon
racing the fuel is 20 castor – 80 methanol – the standard for all competitions. Well, the fact it
that all the engines are on a level peg as they all use the same fuel. No one engine would gain
from a different fuel mix as different fuels are not allowed. There is every chance in the world
that the engine speed would increase a little if a lighter weight oil was used or, say, only 15%
The model car blokes run as low as 8% oil at times and those engines really hoot. A good
quality car engine out of the box is looking a 30 – 35,000 rpm. Yes, yes, I know, different load
factors and all that but they still go bloody hard and synthetic oil is the most popular lubricant.
Back to the drag bit and what it means to you. Well, if you didn’t know about it before then it
hasn’t worried you and it will not be a concern to the majority of modellers. In any case, if you
are using a proprietary brand ready mixed fuel there is a good chance that the oil content could
be as low as 14% if it is not stated on the container.
This new oil does not replace the very popular Coolpower Blue or the Heli Red, it comes sort of
in the middle and is aimed at special applications although it can be used for all fuels including
methanol, petrol, diesel fuel and it will mix at any ratio with nitro methane and also blend with
quite a few other lubricants.