old propnut

I am building a 1/4 Sig Cub And would like some advice on engine size.
I know a 91 4 stroke will fly it, but what kind of performance will I get,would
like to do some aerobatics. Would a 1.20 4 stroke give me what I want or would it be over powered, thanks

JimTrainor

Here is an old thread on the subject:

http://www.rcuniverse.com/forum/m_13...tm.htm#1310508

... no doubt there is more info if you search

invertedpass

I fly a H9 1/4 J-3 with a OS 120 and it has plenty of power, I say go with the 120 you can always pull back on power but if your wide open and need more you are in for trouble.Back in the late 70's I flew a NOLSON J-3 on a Weber .60 Blackhead ,it was slow but it flew like the old 40 HP cub my dad had when I was a boy.Good luck with your Cub[sm=cool.gif]

Patriot

Personally, if you want to go with something scale, I would go with and inverted 4-stroke, like a Laser or Enya. They have their rods on the rear of the cylinder so it allows you to mount it without having to chop up the cowl. You can get an Enya 120 or if you want to get crazy, a 155r. Laser makes a nice 150, which actually runs like a strong 120.

Patriot

CK1

My Feedback: (60)

I'm flying my 1/4 Scale sig Cub on a Saito 150 , Excelent combo for aerobatics , rocker covers are slighty exposed under nose of cowl.
A friend of mine is flying his clipped wing Sig on a Saito 180 , excellent power , very aerobatic for Cub!!!

Capt Jim

My Feedback: (168)

I fly a Great Planes 91 inch wing span Cub, with an OS91 surpass, 4 stroke. Performance is very scale like, which is really what makes a Cub look so wonderfull in the sky. Although it is a relatively slow plane, I can fly it in a very un-Cub-like manner, by rolling it, and doing a loop. The rolls are quite barrel shaped, and the loops need a little down hill run to build up enough speed to carry it over the top....and not too big of a loop at that, or it'll stall and flop out near the top. Knife edge is simply not an option...at least not a very pretty option. The all-up weight, less fuel, is just about 12 pounds. I would like to have additional power available, but other than for pulling vertical, and doing loops, (which is very un-scale like for a Cub), I would be flying it at a much reduced throttle setting, which is actually something I do now with just the modest power of the OS91 4 stroke. My plane is just a little less than 1/4 scale...maybe 22% or 23%, but perhaps this evaluation will give you some feel for what you may anticipate with one that is slightly larger, and heavier. I would guess that you wouldn't be happy with anything less than a 120, 4 stroke, and you may be more pleased with even a bit more horsepower. Cubs do not need a lot of power to fly and look scale, but low power also means that you must FLY the plane, and not just blast off as we typically do with our smaller, grossly overpowered flying rectangles. I hope this helps, and best of luck with your Cub.
Happy landings.

old propnut

Thanks Guys I think I will spend the extra hundred or so and go with the 120