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Thomas,
You could design a cooling system for extended climb, but you would be adding significant drag to the aircraft. There is only so much you can do with cowl flaps. I believe that most builders (and also most certified aircraft) design cooling for cruise, and tolerate temperatures climbing somewhat in climb. There do have to be tolerable limits, however.
I'm afraid that if I built my cooling system to maintain temps on an extended climb, at full power, on a 95 degree day, I would have much cruise speed when I leveled off.
I've seen several discussion on this group, where people leveled off for a while, or reduce power and go to a cruise climb, in order to let thing cool back down. On my aircraft, the oil temperatures are fine, but coolant is marginal on hot days. On a 95 degree day, I could only get to about 2000 feet AGL before my coolant temperature was at redline. Leveling off and reducing power, cools it down, and then I can increase power and continue climbing at a cruise speed. I have some more gains that I can make on mine cooling system by making improvements in air flow. Currently I have some dead space below the radiators which I'm sure allows some air to roll back out. I also have a couple of spots that are allowing air to leak through, which I need to fix as well.
Steve
On Wednesday 14 June 2006 09:30 pm, Thomas y Reina Jakits wrote:
""
> While it doesn't make sense to try to have sufficient cooling for climb,
> I think that I can still make some air flow improvements and get a little
> better cooling.
>
> Steve ""
Steve, what makes you think/believe that!?
I always assumed that one would design/plan for the worst case scenario:
Slow/steep/pro-longed max power climb....
You always can close the flaps/louvers (streamline/reduce drag) when you
change into a less severe regime.
But what good is a 250hp engine if you can't use it for more than 2 min....
I would at least want a 5 min limit for T/O-power. As Rotaries go, they
will hold up fine with max power for cruise/racing/etc. fine too - but if
you can't cool it.....
What if you are in line on really hot day? You might not even get 2 min of
max power.
I would rather err on the wild side of cooling - you always can cut down
and close off, once you know your ride...
TJ
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