Does a 4*60 have un limited vertical with a .91 2 stroke engine? If so which prop suits it best for this?

Thank you.

Hi EObrad, I'm not sure of unlimited vertical, But with a 91 4s I think
a good prop with be a 14x8

Anyone have a 4*60 with a .91?

No, but if you're looking for better vertical, higher diameter, lower pitch prop is best.

If a 14 X 8 is within the recommended range, a 15 X 6, or 16 X 5 would give better vertical.
Dennis-

I just did the maiden on a friend's 4-star 60, with .91FX. This plane has all the vertical you'd ever want with a 4-star.

The .91FX is a rocket with the recommended 13X9 or 13X8, and does not slow the plane much for landing (braking is what the 4-star needs.) A 15X6, on the other hand, provides good braking. I prefer a 14X6 APC (mind you, this is on my old Cermark 60 size Sukhoi), because it provides plenty of power and a bit of braking.

Opinions may differ. Good luck,
Dave Olson

A .91 would be close to unlimited.
I have one powered by a tower .75 and it goes like crazy from takeoff roll to a little dot

I would also try a APC 15x4w this will give you good braking. Dennis

I just finished a 4* 60 with a Mag 91 FS and with full power after take off it will go vertical and keep going untill I let off

I have a 4*60 with a YS .91FZ (supercharged 4-strk) which allows unlimited vertical status easily. Will hover and will pull out nicely. I have a APC 15x6 that works well and also use a APC 14x6 (15x6 trimmed down). I think the .91 2-stroke will give you very good performance and possibly may allow you to go veritcally unlimited. I'm pretty sure it will though. If it is a kit, try to keep it light and I think it may go unlimited. The .91 2-strk, has tons of power if you can rev it up high, but this is going to fly you faster. 2-strks make their power up top and 4-strks make their power lower. The .91 2-strk may not torque roll well, but it will hover it. Try a APC 13x8 or 13x6 for the 2-strk .91 to start off with.

The 2-strk .91 will make more HP than a .91 4-strk, but the 4-strk has way more torque. HP in real life means nothing unless you are going for speed. HP determines how fast you go and torque determines how fast your get there. If you can find the happy medium to allow high revs, but low speed then that is the prop that you want. Large in diameter and low in pitch is the way to go for pulling power. For speed it is the opposite, low diameter and high in pitch.

DTB