would it be possible to make the muffler deflector really long? I want to add a rubber tune to go to the back of the plane. I wonder if this would affect the performance or the engine.

I did something similar once. I used a piece of thin-walled aluminum tubing that was attached to the fuse. It was 1/2" I.D. tubing, but the muffler exhaust was only about 3/8" O.D. so it had about 1/8" of clearance. Being attached to the fuse held it in place.

There was no power loss at all.

Now, on the other hand, I have used those silicon DuBro muffler extensions and suffered a noticeable power loss.

So I don't know if (On the aluminum system) it was the larger diameter, or the openings at both ends or both, but it worked like a charm.

Yes, it will absolutely affect the performance if you put a deflector that long on the engine. The effects can range from a reduction in power to the engine not running at all.

Ken

I had an older man that has been in the hobby for like 40 years tell me that it will cause power loss and may cause the engine to run lean and may cause it to burn up. I dont know my self but thats what this guy told me. I have tried the rubber ones that are about 3 inches on my OS 46fx and it did fine. He said that the long ones can cause trouble.

I have a friend with a tube that's perhaps a bit over a foot long on one of his models. Try it and see what happens. Experimentation is fun!

I made a makeshift exhaust system on a 40 trainer that went straight down the fuse from the the muffler and dumped under the plane. Needless to say the plane ran but lost almost 1800 rpm. So I got rid of the exhaust system.

Four strokes are not as sensitive to long exhausts as two strokes are

ive see some guys run extensions and strapped to the landing gear, but it was a large diameter so it really didnt affect the performance....its kinda like tring to breath out of a coffee straws versus a standard one

The famous engine guru in the magazines Clarence Lee when he tests engines, he runs the exhaust into an old car muffler. It doesn't effect the output of the engine because of its size.

He has neighbors right beside his car garage

I ran clear rubber tubing off the back of my trainers muffler down under the main gear, and it seemed to work great until the tubing fell off. I'm gonna try it again with a nice hose clamp.

This is interesting! I have the same problem of close neighbors. I'd love to be able to cut down the noise so I could run the engine at home....

I did run a couple of tanks through my new TTPro 61 at home but I'm sure the neighbors were annoyed...

Any other ideas for noise reduction at home just for breaking in the engine? I guess performance wouldnt be an issue in this case (just break in running) ???

Steve

There's prop noise also. You run a 10-6 MAS on a OS 46 FX with a Tower 46 muffler and the prop can make as much noise as the engine.

Thats a great idea.[sm=thumbup.gif]

This is exactly what I did, and had the exact same result. I ran some clear tubing down to the main gear on a .46LA. I took out the muffler baffle to compensate. I didn't notice any change in performance, and it did keep the plane cleaner. Eventually it fell off and I didn't bother to put it back on.

You can take some JB weld and make a lip on your muffler tip, let it harden and then slide an extension or tube over it and then use a plastic quick tie to hold it in place. It will stay put permanantly.

My brother and I have both extended the exhaust on our Bipes with rubber extensions and aluminum tube to the landing gear to keep the slime off. He is running a GMS .76 and I was running a GMS .76 and a TT .91 4 st and they all seemed to work well with the exhaust extended. Just got lucky I guess.

You guys just need to switch to 4-strokes. They burn less fuel and make less mess.

Hell, most of the time I don't even need to clean my plane at the end of the day.

A four stroke is also less sensitive to an extension. I've seen extensions run all the way past the tail when using four stroke engines. They run fine.

sourkrout - that is exacly the set up I was thinking about!!!! so that doesn't interfere with performance?

Sourkraut - is your engine 2 stoke or are both, you and your brother's 4 stroke?

Minnflyer: the reason why I don't want to change to 4Stroke is because I've heard they are a lot harder to tune, also, I like that the 2strokes spin faster. But I just hate the mess.
I haven't owned a 4stroke yet, but that's what i hear (hard to tune)

4-strokes aren't any harder to tune than a 2-stroke is. It's just that you tune them differently. But once you learn how to do it's no big deal.

Ken

different in what way? inlight me please because when it comes to 4st i am clueless

You have fallen prey to those people who will find any excuse to avoid trying something new.

A 4-stroke is no harder to tune than a 2-stroke. Many people will also say that 4-strokes need regular valve adjustments - That's a load of bull. I own mostly 4-strokes and have done so for about 20 years. To date, I have adjusted valves twice and one of those times it really didn't even need it.

What IS true about 4-strokes is:

1) You should run at least 10% fuel - 15% is better.

2) You must use a 4-stroke glow plug.

3) They cost more than a comparable 2-stroke

Now, that having been said, a 91 4-stroke will burn much less fuel than a 60 2-stroke. So if you fly just a few times per week, you can save the extra cost in fuel savings in just one season.

And you can say good-bye to that slime on your plane forever!

Hey MinnFlyer that is what I need a "longer extension" ooops, deflector

No extention, more paper towels.

I disagree. I see no difference whatsoever between tuning a 4-stroke or a 2-stroke