OS Max S35 RC Parts/ Information

[Russell Willis]

G'Day All,

I'm presently successfully running a 70'S Vintage S35 in my 1.3 Meter Phoenix Models Sonic. Happy to say after learning to handle/ tune the Engine I'm having a ball flying RC with this venerable older CL Engine. I'd like to obtain parts for the Carb but given it's age they're a bit hard to find. Wondering if You folk might suggest some reliable/ reputable sites or more utd replacements?, also interested in improving it's performance, I've opened up the standard 703 Muffler exit to 9mm exit  and am getting reliable runs on 80/20 Methanol/ Castor (No Nitro thanks). Tacho static sees 10500..10700 RPM on 10*6 Master Air screw G Series Prop. Throttling is quite reliable, Love the crackling note on a less than WOT throttle! Have found this and other CL oriented site a valuable resource!

Thanks in anticipation,

RW

[Rusty]

10% nitro fuel = more power. 

[Paul Smith]

Number 1:  A 10x6 is the accepted Stunt prop for a 35.  But if you want more speed, go to a lesser prop with more RPM.  Trim your 10x6 down to 9.5" and then 9.0".  You will increase the RPM, fuel consumption, power, and speed.

Number 2: Don't get hung up on the stock throttle.  The world (Earth) is full of new RC throttles taken off by CL flyers.  With a bit of grinding JB Weld of epoxy, your can use any throttle you get your hand on.

It doesn't show too well in the pitcher, but it's a Nelson 15 with an OS 15 throttle.  Worked well enough to win for 15 years.

[Dave_Trible]

Shtterman (not a spelling error) on Ebay has some parts but mostly CL I believe.  Otherwise I'd say just Ebay in general,  maybe looking for full replacement engines.   You seem to be getting about all the engine is capable of giving .   If you want more power you may need to just go to a larger engine.  If you try to run that engine too much harder it will just burn up.   Nitro would give you a little more power but I sense you may live in a nitro barren place.  I might suggest something like an Enya .45 which are usually not too hard to find.   It will give you a good shot more power and is fine without nitro.

Dave

[Robert Zambelli]

Russel: I’m pretty sure I have some RC throttles for the OS 35.
If I can find them, they’re yours at no cost to you - you just pay shipping.
I’m away from home now but if you can wait until the 23rd when I return home, I’ll see if I can find them for you.
I have absolutely no use for them.
Bob Zambelli

[Brett Buck]

G'Day All,

I'm presently successfully running a 70'S Vintage S35 in my 1.3 Meter Phoenix Models Sonic. Happy to say after learning to handle/ tune the Engine I'm having a ball flying RC with this venerable older CL Engine. I'd like to obtain parts for the Carb but given it's age they're a bit hard to find. Wondering if You folk might suggest some reliable/ reputable sites or more utd replacements?, also interested in improving it's performance, I've opened up the standard 703 Muffler exit to 9mm exit  and am getting reliable runs on 80/20 Methanol/ Castor (No Nitro thanks).

   I am glad you like the content. Bear in mind that most of us have limited experience beyond CL Stunt, at least as true expertise goes.

     As previously mentioned, using even a little bit of nitro will likely have a tremendous jump in power and consistency. Failing that, a 10-6 is probably not what you want for maximizing power. I would try a variety of 9-6 9-7 APC and other modern propellors. As far as the engine goes, still more muffler reaming is a possibility, making sure you can sleeve it down again if needed. Otherwise, run up the compression until something bad happens.

     I would caution, however, that the OS35 baffle piston engine is well-known for the connecting rod wearing out prematurely in stunt applications, and running more RPM, increasing the compression, or anything else you do to get more power is unlikely to make it better, even if you unload it with a smaller prop. If I was going to run one as you are, I would look around for a NOS connecting rod, and/or find another one of the same dimensions. I vaguely recall that some other engine - maybe a SuperTigre C35 - had a rod with identical critical dimensions but much more robust. I also recall aftermarket manufacturers making replacements. Don't go entirely on my recollection, be sure and check it yourself because I could be misremembering.

      For completeness - in your application, a 25FP would likely be a tremendous jump in power, easier to deal with, and not prone to self-destruction. But you probably already know that.

      Brett

[redout]

Hey Russell

You could send a fellow countryman of ours an email and ask if he has any of his ABC piston/liner sets for the S 35 left over. He has done at least one run of these before. They also came with a new con-rod if I remember correctly.

Edit : I can't find his email address, but you can send him a PM through Stunthanger. Do a search for his name under "Members".

[Steve Helmick]

Hey Russell

You could send a fellow countryman of ours an email and ask if he has any of his ABC piston/liner sets for the S 35 left over. He has done at least one run of these before. They also came with a new con-rod if I remember correctly.

Edit : I can't find his email address, but you can send him a PM through Stunthanger. Do a search for his name under "Members".

"redout" is referring to Brian Gardner. <briangardner_b1@yahoo.com.au>
I might also have one or more of the stock OS carbs and a bunch of used parts, but we're downsizing (sort of) and the model shop currently has laundry drying in it. Arrrgh!  Steve

[M Spencer]

I'd like to obtain parts for the Carb

CARBS ! Carb Parts . HOW MANY DO YA WANT . amin N.S.W. .   

Sendus a p.m. as we've ten zillion OS carbs . never use em .

[redout]

Oh darn ! Sorry I completely missed not supplying Brian's name...

[Motorman]

Reducing internal restriction to flow will help you run bigger carbs. If you can re-time the intake port 35/60 it will give you a hop up. RC engines usually open rather late for better idling and throttle response. You could also cut a small cressent in the piston skirt on the by-pass side. As others have said the main caveat for that engine is the big end of the rod. It will open up, you'll lose compression/timing and the engine will run very poorly. I believe Leonard Newman had some rods made for that engine.

MM    

[Russell Willis]

Hello all and thank you for the various useful replies. Happily flying the engine of which I have two at the moment in my RC aircraft. Thank you for the information and I’ll follow up in due course.

RW

[Russell Willis]

   I am glad you like the content. Bear in mind that most of us have limited experience beyond CL Stunt, at least as true expertise goes.

     As previously mentioned, using even a little bit of nitro will likely have a tremendous jump in power and consistency. Failing that, a 10-6 is probably not what you want for maximizing power. I would try a variety of 9-6 9-7 APC and other modern propellors. As far as the engine goes, still more muffler reaming is a possibility, making sure you can sleeve it down again if needed. Otherwise, run up the compression until something bad happens.

     I would caution, however, that the OS35 baffle piston engine is well-known for the connecting rod wearing out prematurely in stunt applications, and running more RPM, increasing the compression, or anything else you do to get more power is unlikely to make it better, even if you unload it with a smaller prop. If I was going to run one as you are, I would look around for a NOS connecting rod, and/or find another one of the same dimensions. I vaguely recall that some other engine - maybe a SuperTigre C35 - had a rod with identical critical dimensions but much more robust. I also recall aftermarket manufacturers making replacements. Don't go entirely on my recollection, be sure and check it yourself because I could be misremembering.

      For completeness - in your application, a 25FP would likely be a tremendous jump in power, easier to deal with, and not prone to self-destruction. But you probably already know that.

      Brett

Thanks Brett,

Did a lot of Prop testing today playing with 10" Prop and Pitches 4"..5" 10*6 APC provides acceptable Flying at 10..11000 RPM Reliable Tune. Lower Pitches gave approx 1000 more revs but didn't translate into improved Aerial Performance. Have 9*4, 9*6 and 9*9's I'll give 'em a Go and see if They work out. Starting to think APC 10*6 is the go though. Appreciate the assistance and info, have pm'd Brian Gardner. The Airframe I have the S35 is a bit on the big side. Planning to do a 1 Meter Ugly Stik v Light for it.

Regards,

RW

[Colin McRae]

I believe you are running 20% oil in your Max 35. If it were me, I would run with a little more oil. I have a Max 30 on a CL model and run 25% oil.

I also have a carb (from my RC Max 30 that I converted to CL) that I will never use. You are welcome to have it if you cover the shipping costs.

[Rusty]

I suggest getting an OS 32 SX rc engine.  That will have, probably, 1/3 to 1/2 more power. 

[Robert Zambelli]

Russel - I located some RC carbs or the Max-S 35.
If you still need them, they're yours for free - just cover postage.

Bob Z.