fly4food18

My Feedback: (15)

I would love to see some pictures. I have never tried to post before. my e-mail is

[email protected].

if you could please send them to me.

Thanks
Brian

Otto Kudrna

My Feedback: (1)

With out offending anyone, just to be "a Smart A**" May I just say "told you so". It is not you, it is not the engine, it is just the multi blade prop at the given available rpm of the engine and the inefficiency of such prop. This comment is not directed at anyone on this thread but more so the thread in the Scale Aircraft section which has been going on for about a month now. There have been engineers trying to explain to some modelers why not to run a four blade prop, but some people just like the look so mush, it is impossible to talk them out of using one. Actually there is a way you can do it on these engines, but props with as much blade pitch as would be required and the blade with required can only be achieved by buying very large props and cutting them down to a smaller diameter. The second thing which no one takes into account is that ALL three and four blade props used on FAST aircraft, have variable pitch. If this was available to us, it would make the use of 3 and 4 blade props practical for us also. The only real airplane that I can think of, which used a fixed pitch prop with more than 2 blades, was the Fairy Swordfish. And as we all know this airplane was all wing, and flew at the same speed as it took off and landed. I plan on running a 26x16, four blade prop on a 82" Tempest. This prop will be only 2" under scale. The power unit which will be used, will be 2 RCV 120s coupled together with a second reduction unit dropping the RPM down another 40* at the prop. When I have the results, I will post specs. and pictures of the unit. I have made a deal with RCV, that if this unit works, and if there is interest, that they will produce a 3-4ci SP series engine for us scale fliers.
The last thing I would like to state is, that these engines do have a tendency to run a bit hotter than other engines. This is for two reasons. The first is because, there is no cylinder hanging in the slip stream to provide lots of cooling. Second, the actual cylinder makes no contact with the front housing of the engine. This is why the engine must always be run on the rich side and must use HI viscosity oils in the fuels. This is why some fuels work better than others. This is also why the oil quantity is not as important as the oil type. These engines like low oil content but thick oil.

Thank You for your understanding
Otto Kudrna (fellow modeler and experienced RCV user, in this post)