I am using the smaller crank pulley on my RV6A with the 2.85 gearbox

and

13psi rad. cap.
No problems taxiing or fast cruise but first 4000' climb on a very hot

day

has to be limited to 500-1000ft/min.
Ian Beadle Australia.

Ian get a higher pressure cap. I think that will help. Have you built a

water

manometer and checked the aero pressures on both sides of the radiators?

Paul Lamar

Paul,
I've been thinking about radiators and feel that for those who haven't the
room
under the engine an alternative would be to build two smaller radiators into
the
sides of the of the cowl ( flat to the side) (with appropriate baffle - bell
shape)
with a cheek coverover the top of the each rad (attached externally -
appropriate shape).

The cheek cover would create a low presssure area - therefore help suck out
the hot air (at the rear) this could also have the adjustable cowl flaps set
up as well.

The idea here is to seperate the radiator air from the engine compartment,
eliminating the back-side pressure build up which is causing so many
problems.
The back side here is open to outside air but protected by the cheek cowl
cover.
This should give more room under the cowl and keep rads away from other
things like exhaust etc.

This allows the cowl to be utilized for more than a cover - it provides for
the
cowl to be used as part of the baffle, rad holder (with appropriate support)
and facilitates hot air egress.

I have seen this principle used before and I believe I will go this way !
If you would like a drawing I will do one -up.
George (down under)

That will work fine. In fact some very successful liquid cooled aircraft
engine installations use that technique. The problem with two radiators is
the liquid cooled plumbing system is mission critical. A leak can cause engine
failure. Everything you can possible do make the cooling system more reliable
should be done. One radiator has fewer connections to go wrong than two radiators.

It is not hard to mount one radiator under the rotary engine if the starter
is put in the right place and the motor mount is designed for that in mind.

Paul Lamar
 
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