Hi B73, Happy days indeed - and it looks like we're doing it all over again.
Fuel injection would add very little weight - in the order of literally a couple of pounds, the extra significant components being the 2 fuel pumps. The servo is not greatly different in weight to the carb and might actually be lighter. (anyone got the actual weights handy?) The power output is determined by the manifold pressure limitation as is the case with the carburettor version so the transmissions ability to handle it is a non issue - not that its likely to be anywhere near its loading limit as applied.
The cost of initial installation in proportion to the cost of the helicopter would be modest. (Based on the cost of replacing it on an Enstrom.)
If you want to see an injection installation which could be applied to the Robinson one needs look no further than the Enstrom non turbo models which use a Lycoming 360 with injection. My aircraft is in for its annual at the same place as an R22 beta2 is being done. I will take some pictures to show how similar they are at the weekend. I'll post them up. Judge for yourself then.
The cost and effort of global re-certification and Frank's desire to do it are the limiting factors. I guess he would rather sell you a Raven 2. Frank was at one time happy to move from a 320 to a 360 for the beta2. A far bigger change than applying injection. If he really wanted, injection could be substituted as it was on the Astro.
Hooloovoo.
The Lyco is inefficient as applied in the Robbie as it runs on the wrong side of the mixture curve. 1/3 of the fuel is wasted.
lt is quite possible to run a Lycoming with injection in an extremely efficient manner. Much has been written here and elsewhere on that by myself and others.
You are correct. Most of the time your car produces very little power and in actual fact its specific fuel consumption will be worse than a Lycoming. Specific fuel consumption is a good measure of efficiency as it is a measure of weight of fuel used per horsepower per hour. The Lycoming can be made pretty damn good- even in comparison to modern gasoline engines.
Rotorfossil. Injection is neither heavy nor complex as applied by Bendix. In fact it is positively crude. It does have one advantage though. No ice. Oh, and its dead reliable.
Ericferret shouts diesels!!!!!.
He may be right ultimately but last time I checked the power to weight of the SMA diesel was inferior to the good ol Lycosaurus. I'm sure someone will do it sooner or later with a diesel - but it wont be an R22.
Edit : I forgot to mention that the 5 minute rating is to keep the temps acceptable and keep Franks (rightly) prized reliability. Nothing to do with the transmission.
Last edited by Gaseous; 7th November 2007 at 20:06.