Hello,
I was wondering if anybody has tried pulling the ABL liner and piston out of an OS .32 SX-A and replaced it with the ringed liner, piston and ring of the .32 SX-HX before?

I heard that the OS plating isn't very good (though I own a .25 FP and a .25 LA and never had any problems) and I want to convert this engine to ringed.

I realise that there are other engines out there of similar capacities that are far cheaper, and this engine + ringed parts would cost around $400 New Zealand dollars to import from tower hobbies.
But I like it's power output, and I'm spending a bit of money building a .25 sized pattern ship.

(P.S. have any of you older guys flown a Philibuster low wing .20 sport plane, plan by Phil Greeno, 42 in span, if so.. how does it perform?)

thanks,
-Jeremy.

There will not be any performance difference between the ABN and a ringed cylinder assembly.

Run the ABN until it peels then think about replacement?

Enjoy,

Jim

Jeremy:

A few years ago when I did the major overhaul on my Concept 30 heli the piston, liner, and ring for the OS 32SX-H cost more than the complete engine. Then add the cost of a set of bearings...

I don't know if OS' parts pricing is as ridiculous in Oz as it is in the USA, but I woulod suspect it is. If that is the case it would be less epensive just to buy the ringed engine complete and be done with it.

However, I think I heard that OS had discontinued the ringed version of the 32 heli engine, and now supply it only in ABN.

Bill.

That is correct. The new Heli's are ABN See the link... http://www2.towerhobbies.com/cgi-bin...&I=LXBZ03&P=ML

The ringed sleeve/piston/ring would be $69 + shipping in the US Then there are the bearings

Hang on to your ringed engines...

Jim:

That is about 1/2 the price I was quoted roughly three years ago. Are you sure you haven't priced the ABN piston and sleeve set?

Bill.

Just looked at the parts listing, and Jim, you're right. Right at $50 for the piston and sleeve, I didn't see the ring listed. But there's always Frank Bowman...

Bill.

http://www2.towerhobbies.com/cgi-bin...?&I=LXNK38&P=7

http://www2.towerhobbies.com/cgi-bin...?&I=LXNK37&P=7

http://www2.towerhobbies.com/cgi-bin...?&I=LXCT17&P=7

Get a load of the price they ask for the ring?

Enjoy,

jim

Jim:

Quote:

...the price they ask for the ring?

OUCH! As I said, Frank Bowman is waiting in the wings. But when you add freight from two places instead of one, might be as cheap to buy the ring along with the piston and sleeve.

Bill.

Thanks for the info.
I've done a quick check (tower, osengines.com, os-engine.co.jp), the .32 SX-H is ABL, but OS still make a ringed .32 SX. the SX-HX. It's the same as the SX-H but with a ringed piston, steel liner and a pullstart.

As far as money goes, it doesn't really matter to me, I just want a good engine.

Would any of you reccomend I do this conversion if I want a good quality engine that will last years?
(as far as I know the peeling issue is the only problem with OS)

Jeremy:

Get the parts while they are still available, and you might get a con rod to go along with the other bits.

Then set them aside until the original piston and liner are worn out, or the sleeve peels.

Bill.

Don't get too stuck on the 32. It will soon be a 37.

The LEO 37 is a real runner as well as the Thunder Tiger 36.

Enjoy,

Jim

Jeremy. I have accumulated boxes of tired, worn out or broken engine of many makes over the years and hands down I have to say the best engine I've ever owned is the little OS 32 SX (the only OS I'll ever buy again and just did). The engine was first mounted on a kangie F-3D until many flights later it made a large crater in the ground.[:@] The 32 was then clean up and mounted on several 30" pizza box fliers (the coroplast got too mangled) where it still resides to this day. I recently totally tore it down to clean and glass bead the out side of it because it was so gross with black goo from many hours of running. To my pleasant surprise it had very little wear. Just cleaned it up and slapped it together same bearing and all. The thing you have to understand is this engine has been thoroughly abused by constant screaming full throttle, always used with a Mack's tuned quiet pipe, many lean runs, countless gallons burned, half dozen auger in's, cutting grass ,too many props to count, Yet it still has good compression, idles and runs like day one. I've gotten my monies worth ten fold. The only thing I've done nice to it is that I run it dry of fuel, add 5 drops of ATF in the carb and spin it, then store it nose down to keep the bearing covered in oil every time. Sooo, what I guess I'm getting at is how can you improve upon perfection by adding a ringed piston???

A .37 aero version actually in the works? I have been giving the .37 heli engine fond looks and wishing..... It would probably be $150 though which is sad.

I am most impressed with my 32 that is in an Uproar. With a Mac's black muffler and 11x3 prop, it hauls that Uproar mightily straight up forever which is surprising. Cute as it can be with the engine mounted lower than 90 degrees and the Mac's muffler coming out right between the landing gear.

Ernie

Thankyou.
Yes, the SX does seem to be a very good engine, and very well designed too, by the look of the redline (22,000 RPM).
I just thought that a ringed conversion might extend it's reliability further.
I have never heard of the plating peeling on any OS engine or otherwise in New Zealand (possibly just the american batches?)
but I have heard of engines gradually loosing compression over time, I thought ringed constriction might retain it's compression longer over time in this good little engine.

-Jeremy