Not to be presumptious, but it has been my experience that the exhaust pilses from an engine especially at the lower rpms, will not be sufficient in volume or steady enough to support more than one instrument with regular vacuum. The best solution short of a vacuum pump, would be to either install an emissions air pump with a belt drive and reverse the connections to create suction, or use a vacuum venturi and mount it inside the cowling just behind one head so that heated air flows through it, as well as getting a prime of vauum from the prop wash through the engine compartment/cowling. This should provide adequate vacuum for initial spin-up of the instruments, and also guard against icing if inadvertant IMC is encountered. All tend to agree that the whole configuration and purpose of the KR2, or KR1 is VFR only, but the insurance would be nice. When I flew the Cessna 172RG, and the Beech Duchess's they have their carb intake air drawn from behind the left hand head, and then ducted down to a side draft carb below the oil pan. This layout allowed us to basically never have to use carb heat in any flight condition due to the already pre-warmed air, even after simulated emergency descents, etc... The should be adequate heat to prevent the venturi from icing. If I add a vacuum system on mine, this is where I intend to add the venturi. It will also keep it from adding drag to the exterior.
Colin Rainey crain...@cfl.rr.com Sanford, Florida FLY SAFE!!!!
