very far from cox but still glow power

ok, im just wondering if it will damage the engine because of there being no muffler, ie making it run more lean

Mitch:

Older engines were most often run without mufflers until regulations requiring them were enacted. The "add on" mufflers came into use to comply with noise restrictions and nothing more.

People who complain about noise don't much care about engine damage.

According to OS's website, the s-35 was made in the early 60's. The early OS motors seem to have a reputation of excellent power output, at least on the RC Forums.

As for running the motor without a muffler, I don't think it would damage it. if the motor was designed for one, it would just affect the performance.

In my younger days, ALL engines were run without silencers (mufflers) and certainly the OS range in the early 60s were not designed to use them. You cannot "Damage" an engine by adding/removing a silencer, just reduce it's power output if you fit one on an engine not designed to use one. The only reason that silencers are universal now is because of the loss of many flying sites due to noise complaints, I live way out in the country with no-one to complain, and I run virtually all engines without them.
The one exception are racing engines which use what is called a "Tuned pipe" these engines will often not run at all without the silencer because the system actually relies on the exhaust backpressure to help the timing, but the OS is not one of these.
If you have no problem with noise annoying anyone, go ahead and run the engine as it is!

I've wondered how a tuned pipe works. Is that the long tube that looks like it has a big collector swept way back to a small outlet?

http://en.wikipedia.org/wiki/Two-stroke_engine

scroll have way down and it shows how a expansion pipe works

thanks for the input guys, thanks for the pic Puffie40, thats the exact engine that i have minus the muffler

Tnx Mitch. Good info.
Bob

dckrsn wrote:
Tnx Mitch. ood info.
Bob

no problem man

Great illustration. I had to stare at it for a few minutes. I think I've got it. Looks tricky to tune.

From what I see and have heard, the tuning(pipe tuning) is done
by adjusting the pipe length between the exhaust port and the
expansion chamber.I guess you could use a telescoping pipe to find the sweet spot.

Different length flex couplers, trimming the tip(stinger end) are the two biggies for fine tuning a tuned pipe. There are HUGE gains to be had, but it takes cubic bucks once you get to tuned pipes and custom built motor. Whole different tax bracket.

The outrigger nitro hydro racers thrive on this stuff. I mean we are talking REALLY fast boats. Been to a couple of these races.
https://www.youtube.com/watch?v=4xlgK-Nzxe4&feature=related

mitchg95 wrote:http://en.wikipedia.org/wiki/Two-stroke_engine

scroll have way down and it shows how a expansion pipe works

thanks for the input guys, thanks for the pic Puffie40, thats the exact engine that i have minus the muffler

I'm glad you found that! I'm not technical enough to explain, or really understand it fully!

If you *Really* want to know more about tuning two-strokes, This book can help.

Puffie40 wrote:If you *Really* want to know more about tuning two-strokes, This book can help.

That looks like a great book, I'll have to read it sometime.

yeah, i have a tuned expansion pipe in my 1/5th scale hpi baja 5b's engine that is 30.5cc

This is why my Parents Neighbours enjoyed my residence so much circa 1982


https://www.youtube.com/watch?v=esTd8kMn-lI&feature=related

You Guys got guns we had insane 2 stroke road bikes.