Rotecradial-cast heads.

[facthunter]

Both the 7 & 9 cylinder engines appear to have new cast cylinder heads. This is one pretty neat looking pair of engines now. Nev...

 

 

[blueshed]

Hi Facthunter

 

What would be the most suitable airframe for the 9 cyl Rotec, with two seats, fast and still in the RAA catagorey, ????????

 

Cheers Guy

 

 

[facthunter]

Suitable airframe.

 

Guy, your requirement for FAST, is a hard one here as ,without an exotic cowling, the engine would have a lot of form drag ( parasite ). The 9 cylinder motor is quite heavy by ultralight standards, though it is commendably light for the type of engine that it is. This would need a short nosed design ie. CUB replica, or the Australian Aircraft Kits HORNET. They are not going to be fast, and you would have to watch your all- up weight, unless we get 750 Kgs or you go experimental VH reg. ie. PPL required.

 

You would have to consider making it flown solo from the rear seat only , to aid balancing if you go tandem seating. which would help with the speed factor. (Cross sectional area reduction) but ,with a big diameter engine in front, you would probably not gain much that way.

 

The Murphy REBEL would have no trouble with that engine and you might get 105 knots cruise if you clean up the strut fairings etc. wheel spats and the COWL. It would probably benefit from having a bit taken off the wingspan as well but you would spoil a good aeroplane. Just my thoughts. At least these aeroplanes would look terrific, and if you put a ring type of exhaust, instead of the stacks, you would get a better "radial" NOISE and perhaps eliminate some of the exhaust smell with a single outlet pipe. This configuration of engine suits a centrifugal supercharger as it needs a diffuser to ensure the mixture is evenly distributed to the cylinders, so you are already half-way there. Just my thoughts. Nev...