On 10/03/2012 10:51 PM, Jeremy Fisher wrote:
> 1. I just bought a refurbished Rotax 914. Is it worth the hassle to
> fit an intercooler?
I have an intercooler but I found it not worth it. In the standard
cooling configuration it is highly doubtfull the intercooler will work
anyway, as there is hardly any pressure drop over the intercooler for
the cooling air (the exit is in the cowling, which is not exactly a low
pressure area). Even after reworking the whole cooling system, which is
a major project, and getting enough pressure drop over the intercooler,
the result is still hardly noticable. Also, the intercooler won't do
anything good during the cruise (in fact, it just creates drag) so it
can only beneficial during take off. As the 914 can take off in a
shorter distance than needed to land, it is questionable whether even a
shorter take off roll would be of any significance. At the same time,
the intercooler adds weight, adds drag (you can't get air through it for
free) and makes relocation of the oil tank to a more cumbersome location
necessary (at the port side there is less room, and the hose routing is
more complicated) So, if I would start all over again, I would probably
leave the intercooler out, it is not worth it.
> 3. I am far from impressed by the cooling set up, and I know that
> lots of people have modified the standard system. Has anyone used
> the Laminova oil to water cooler, and if so, which size did you use,
> and what was the result?
I have the Laminova heat exchanger with great results, but I have
entirely changed the rest of the cooling setup as well. Provided you
have a highly efficent water cooling, the Laminova has the benefit of
tightly coupling the oil temp to the water temp (reducing stress in the
engine) and allowing superfast oil warm up times without having to
resort to an oil thermostat. It also makes it less complicated to get an
efficent engine cooling; you only have to focus on getting the water
cooling working ok, designing a proper ducting for it, and have one cowl
flap to control both the temperature of the water and oil.
For the 914 you need the larger Laminova with a plug in the coolant
hole, there is a special light weight version of the Laminova availabe.
Beware, due to the tiny canals in the Laminova, you can't use the Evans
coolant. 50/50 works very well though.
Frans
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