To thermostat or not is indeed a debate; I have experienced both failed states of a thermostat (1 stuck open  /  1 stuck closed) and therefore chose NOT to put one in my aircraft.  In hot weather conditions there is no real advantage to having a thermostat; however, in severe cold climates there is.  Once I get back in the air with my machine I may experiment with one for winter operations.

 

As for radiator size that Tracy and others are using – it is about 700 Cu inches and not 540 … see link: http://www.summitracing.com/parts/GRI-2-58185-X/

22x13x3 = 858 cu in; subtract 2 inches off each end for tanks gives 18x13x3 = 702 cu in … I have the same radiator but not yet flying with it – rebuilding.

Jeff

 

 

From: Stephen Izett <steveizett@me.com> Subject: Re: [FlyRotary] Re: Cooling Water Temp Date: Wed, 18 Dec 2013 17:17:36 +0800 To: Rotary motors in aircraft <flyrotary@lancaironline.net> <image001.gif> <image002.gif>

Hi Neil   I've listened over the years to the debate over thermostats. What makes sense to me is reducing the intake as much as possible and using cowl flaps to increase the delta P across the face of the core/s and so to minimise cooling drag. And I'm with you, I have never known a thermostat to fail and it seems its a great way to stabilise and quickly establish operating temps. I took the one out of our Renesis 4 port and hope we'll be OK with our setup and add the cowl flaps as needed after testing.   I have always found Paul L very helpful though some of the figures for radiator area and intake area are quite large (600cu inch) compared with a number of flying examples that are cooling well.  My research: (I believe the numbers are accurate) Ian Beadle RV6 - 374cu inch water cooler (similar to your setup me thinks) He reduce his intake size significantly while still cooling. It was all about diffuser shape. Dave Leonard RV6 - 422cu inch water cooler (again similar under setup as yours) Tracy's 3 rotor RV8 - 540cu inch fed by a 5 1/4" (22in2) intake. I have tried to model of this setup. 2/3 of Tracy's would be 360cu inch cooler with an inlet area of 15in2. Ours is 540ch inch cooler with a 18in2 intake. Hoping our diffuser is somewhat as efficient as Tracy's.   Hey I'm not flying so my wisdom could be vapor.   Cheers   Steve Izett Perth Oz

 

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