Hello,

I have a very old OS 40 4-Stroke FS. I want to put it in a plane, but just don't see very many smaller ARFs or Kits that would be okay with a .40 4-stroke. Any recommendations. does NOT have to be trainer as I am an experienced pilot...just want to get this engine to use.....

Chris

First thing that came to mind.

I would love to have that motor and this kit.. Just me


[link=http://www.sigmfg.com/cgi-bin/dpsmart.exe/ProductsV6.html?L+Sig+czvy0035+_Ddp_5fSearch1_02a0 1RCSigLClippedCub_01Search_02Index_01Menu_02CatPro d_01Thumb_02Kits_20_2d_20Scale_20Models_01]SIG clipped wing Cub[/link]

G'day

I have an OS FS 40 like yours. The most fun I had with it was in a Kadet Senior. It was just powerful enough to fly the Kadet. Take offs were like a WWII bomber with a full bomb and fuel load - long and gentle but once in the air I could reduce power and float around.

Next I put it in a 40 size Boomerang Trainer. It flew OK but had nothing in reserve.

Its best performance was in a scratch built Cirrus Moth. Somewhere out there is a Boddington plan for a Cirrus moth for the OS 20 FS and we scaled it up a bit to about 50 inches wingspan and three of us built the model and put OS FS 40s in them They were a perfect match and flew really well.

My final attempt was to put it in a Phoenix Tiger Moth but it was just not quite powerful enough and the model now has a Saito 40 in it which is perfect.

I did toy with the idea of putting it in a Goldberg Cub. I had flown it with an elderly Enya 46 4c. I tried an OS 40 Surpass but it was just not enough so the 40FS would have been far too small.

There are a number of ARF smallish Cubs around - one of them would probably work well, so would a Sig LT-25 and the Sig Kadet Seniorita (I flew mine on a PAW 15 diesel at one stage and they fly well on a 30 four stroke.)

Have fun with it. They are really sweet running engines. Mine has recently had a new ring and bearings but like yours is "between engagements" at the moment.

Mike in Oz

I would have to agree with Mike109, Its all about expectations and while I don,t own one but have flown one or two in the past the Old 40FS especially the first open rocker version is decidedly anemic by standards the fellows all seem to expect these days.

Therefore I would suggest a vintage type old timer perhaps something like the eighty inch Playboy which would excell with that engine and be a perfect match.


John

Look at House of Balsa web site for smaller planes. I think the little engine I had was a .48?? I used it in a small space walker. Been a while. What John mentioned about the older four strokes is really true, compared to what we have today they were pretty anemic. Todays top four strokes are about the same as there two stroke counter parts, not in rpm but torque, they can really pull around a plane. YS is in a class all by itself but I won't get into that. I still use my OS four strokes too.

Ever thought about putting it in a monster truck? All you'd need is a fan and the valvetrain from the FS-40C and you'd be golden.

Some options:

Almost any .32 plane will be fine with that engine.

An Asian Ultimate .40 size plane will work great with it too.

e.g. a World Model's Ultimate...

I expect mine will go into a Fred Reese Golden Oldie, which is a vintage looking bipe. RCM carries the plans, and it doesn't look difficult.

I really like the Gypsy or Cirrus Moth idea, though. This is a putt-putt motor and that's how I'd use it.

Jim

Can you get an Airsail Beaver kit over there?

Mine flies nicely with an LA40, so a 40FS should be OK too. Might need the firewall shifted back to accommodate a 4S.

Other small plane I have is a House of Balsa PT19 with a 25FX in.

Terry