Hello Good People,

Have an OS 91 FX engine on a Twist 60.

Would like to put a smoke system in it. Was thinking about the Sullivan one.

Question: Will the OS 91 FX get the muffler hot enough for good smoke or are two strokes just a waste of time to get decent smoke?

Was going to use a preheater too.

Thanks in advance!!!

You are going to have a tremendous weight penalty from the smoke system. The performance you have enjoyed with your plane will be gone.

To use a smoke system you need a larger plane so that the weight of the smoke system is a smaller percentage of the over all weight

GF,


I stand by Jim on this...

A smoke system of this sort is for regular aerobatic planes, that would 'sky-write'... Not for a light 3D plane like the Twist .60...

W8 & Dar,

Thanks for your input. Will take it under advisement, but you both didn't answer my question about the engine.

Regarding the weight issue, have you both seen the twist 60 fly? With a 75, it's practically unlimited and the wing has lift to burn.

Thanks again guys.

Glowfuel.

GF,


Most of us don't have ALL the experience...

Each knows about some things and does his best to provide the answer to that part of your question.
For example, I have never personally used a smoke system, so I don't know if the OS will get its exhaust hot enough to produce effective smoke...

If you really want to get your question answered, please edit the first post and change the title, so everyone will know you are asking about a smoke system for your engine - not just a general OS question.[sm=confused.gif]

I am very familiar with the plane. The guy I fly with has one with a Saito 125 four stroke. It is his favorite plane. But part of the secret is its lightness versus the wing area and power. You will destroy this with a smoke system's weight. He had a OS 91FX on it then a Saito 100 and eventually changed to the 125.

Farther more, the exhaust temperature of a OS 91FX is marginal to make smoke. It will make smoke but not like you have seen the bigger planes do. There is not going to be giant clouds of smoke drifting away from your vertical hover. You will even be unlikely to get it to hover with the added weight of the smoke system. It will make a little smoke however.

W8,

Thanks for your input.

The Twist 60 that I fly will hover about 3/8 trottle. I have no doubt that the smoke system will somewhat deminish the flight performance on my flying with the added weight, but probably would be still able to a lot of the maneuvers.

Believe it or not, used to have a full smoke system in a Hangar 9 Aresti 40. Saito 72 up front. No that was a bit heavy for sure.

As long as you had good power on take off, the plane actually flew very well with smoke on.

Anyway, can't imagine anything more than a 91 on the twist 60. Your friend must be a real power user. It's one of my favorite planes as well, W8.

Believe the best thing is to probably keep it light, as mentioned. Perhaps will add a smoke cartridge to the underside instead.

Keep'em flying....

Dar,

Thanks for you input as well.

Well, the post and question is what it is. Like you said either you have the experience or you don't.


Glowfuel

Surprisingly the Saito 125 is a natural in the Twist 60. There is no balance problem and the engine fit in the same holes as the Saito 100. Needless to say he only uses bursts of full power. I love to watch him fly it. After getting the Twist 60, he sold all his pattern planes.

I think the smoke cartridge would be a sure thing for you in your plane.

Two stroke glow engines have a relatively cool exhaust compared with the four strokes and gasoline engines.

That is surprising. Especially when the Twist 60 isn't a pattern plane, but can be very smooth (pilot able).
I like to do rolling circles and extreme flat spins with mine.

Yes the 4 cycles and gassers are much hotter, but wan't sure on the amount of (hotness) compared to a 2 cycle of the same displacement.

The smoke cartridges seem to be catching on in popularity. Think I may try them out this year at our club show and the upside is no messy oil to deal with.

My friend only flies 3D any more since he discovered the Twist 3D. Forget pattern. He is 64 or 65 years old.

He also has two UCD 60's. One has a OS 120AX and the new unflown UCD has a Saito 125. He flew the one with the 120AX all last year. It is a hoot also. The first UCD was given to him when another friend crashed it. The nose was destroyed. He rebuilt the UCD to look better than it did when the first guy crashed it. My friend has a second Twist 60 that he scratch built from measuring the ARF. But he hasn't flown it. He been flying the first Twist since April 2006.

There's another guy that used to fly with us that had a UCD 40 with a Saito 100 (several different ones in fact). That was pretty nice also. The 100 fit the plane like that was the designer's intended engine. This guy now just flies the very big 150cc gassers with smoke systems.

64 or 65 and doing 3D, sounds nice. God Bless him.

Pattern is a lot of fun for me and teaches discipline in ones flying. Some people lack that in their maneuvers.

The twist 60 can be flown in pattern flying too. True all-around type plane. The 91 FX provides a ton of power for the bird. Nice [8D]