Hull
Boat (Hull), a Tornado T5 from dave marles
I choosed The T5 normally we use a gearbox to reduce the propeller rpm on the smaller engines due to "to high rpm" for direct drive. The 15cc have we not geared since the Webra era finished early 1980.
With smaller propeller does the efficiency decrease which is equal to powerloss relative a bigger propeller but the torque decreaces with a smaller propeller and that gives a more stabil boat in the water.
To gain power i will test propeller diameter 55-60mm and there the T5 will fit in well with referens to 27cc engines that already are using this kind of props presently.
T5 is working well with these big props so I am lookingn forward to test. From last year I learned that the speed is very simular geared vs straight but the drivability is much better with the geared version
I will keep the weight to a minimum because we accelerate 4 times /lap + middleboy partly. I choose light material as far I can.
Rudder, I have used a own design se album
Modifying the deck to enable the engine to be located under the deck
Mainly is it the engine cover that I will modify so the e/g fits under deck
I entend to update my allbum with photos and comments allong the building process. Use Google translate for reading my comments
