I recently got the .26 glow engine NIB on auction and have some questions:

1) The muffler is quite small. Morris sells a quiet muffler, and Carlson has a pipe (mvvs302) for a 3.5, which this is close to. But in another thread I read about a 3243 pipe that is designed for larger props. I'm hoping to use a 10x4 if possible, or maybe a Bolly 9.5x5. I assume the quiet muffler will give the lowest noise and the pipe will give the most power. Can someone tell me any more to help me compare these choices? And if the pipe would be best, where does a U.S. buyer like me get one?

2) The English instructions with mine were pretty sketchy. I gather this is ABC, so break-in at a slightly rich 2 cycle? It recommends 100% castor for lube. It's a little hard to get, but I can get half castor half synth. Good enough?

Thanks in advance,
Jim

Jim,


A US buyer would be asked to go overseas to get his MVVS engines and parts...

With the Internet and E-mail it really ain't that complicated anymore; and with PayPal, neither is payment.


You know the 'crew' here, so there you go.


Your wrote MVVS302? That's Carlson's catalog number... Not any MVVS number.

The #3243 is the side-exhaust version of the tuned silencer and there is the #3244, if you want to set up your new MVVS in rear-exhaust guise.

These would be good for 13-17,000 RPM.


If you want to spin a small prop even faster, the #3241/#3242 of the 2.0 and 2.5 cc engines, can bring up pretty crazy numbers with the .26/4.2 cc engine.

I have tested the 3241 mufflers with the larger engines. They start gaining power above 16500 rpm, where the 3243 slowly cuts off. Rpm range of the .26 engine thus becomes 12,000 to 19,000, which is quite flexible to say the least.
I am afraid these engines will soon be a thing of the past, until order numbers are kept up. No company can market a product and operate at a loss.

Thank you for the responses. Sorry to hear the company is struggling. I look forward to trying this engine one of these days. We're at about 8 F today, so no prop flipping just now. I will need to find all castor fuel first too, I guess. Morris has the silent muffler so I will probably try that.

Jim

Jim,


With you sitting smack in the middle of the icebox, 8ºF is cold, but it can still be worse...

As people dealing for MVVS, we more strongly feel the changes MVVS is going through, due mostly (but not solely) to market changes.


It is not directly related to your query, but some of the glow engines MVVS have discontinued, have been replaced by [link=http://mvvs.cz/elektromotory.html]very high caliber electric motors[/link].

Just look around you where you fly; how often do you now see a newbie come along with a glow-powered plane!?


Or, should I say, the glow engines MVVS still produce, are those that have not yet had an electric motor designed to replace them...

Jim,
MVVS is not struggling. They just are evolving to gas engines and electrics, because they have the future. I see that when I go fly. Electrics for the smaller fry, and gas engines for the large planes. Glow engines mostly have been e-bayed, so for a factory there is no future there. We, as dealers can keep you covered for a while, but we do loose money in the process, wich is not a healthy business foundation.

Well, it's a smart move on their part; no question which way the wind is blowing. Though, I hadn't thought about gas retaining it's place. Makes sense, since batteries are still expensive on a large scale.

But I will never love an electric motor as I love my glow engines. Thanks for keeping things going. I know the day is coming when glow engines will be a small niche in the hobby.

Jim

That is the time to go gas. I too find no pleasure in electric flight. Engines are much more to my liking

I found some info about the various mufflers: http://www.rconline.net/magazin-2001...iationen.shtml

From this, the silent muffler really costs a LOT of power. Unfortunately the 3243 pipe is not a lot quieter than the little stock muffler, but my, it does let 'er turn up!

Tests were on a .21 turning a "too large" 9x7 MA. I think the 1000 rpm loss of the silent muffler isn't worth it to me.

Jim

Jim,


I seem to remember Pé offering an 'after muffler' that fits behind the #3243, which reduces its sound intensity by about 5 dB.

It also boost performance by a couple of hundred RPM...

Now, that is the most shortsighted report I ever read. This guy never took the effort to get the systems in tune, and never analized what was going on. What he did do was voice a "feeling" of how things should have been. Be it understood those were HIS feelings, serving his readers' views.

As you can see from the dB readings which are objective, the tuned muffler is about half as loud as the "std" muffler. This is a 3dB gain without any effort, and with a lot of power gain. Had he tested the engine to higher rpm, he would have found quite different figures, as the std muffler gains power to the value equal with the tuned muffler. The std side exhaust dump bucket is an occarino, which has a tune of it's own
However, since the tuned muffler is a high pass system, the sound is not the most pleasant. Therefore, this muffler has friends and enemies.
By adding a low-pass muffler (which is what I did), the unpleasant high pitch note note is removed. The engine back pressure is increased slightly causing a slight power rise, and noise reduction is between 3 and 5 dB, all with a size package and weight much smaller than the Mac's.
This goes to show, that power does not equal noise

Thanks much for the comments on this report, Pe. I wasn't able to get much from the German, so I was going on the stats.

What do you think of the silent muffler stats? That is the one, for mounting simplicity and noise reduction, that I would choose, if it didn't cost so much in power. The MVVS ads say that this muffler gives a little increase over the standard muffler, but in this test an awful lot of power was lost.

Jim

If you add an extra muffler to the occarino type side dump muffler, a lot of power is lost. That side dump muffler is not great to begin with, because it is way too small, and this discrepancy is reflected downstream if you add extra restrictions.
OTOH, If you add the same type of aftermuffler to their black tuned muffler, all the gains are yours for the taking, both noisewise and powerwise. The tuned section only sees the increased back pressure, which in this case is beneficial, because in these engines it aids the scavenging process efficiency. (beware, this is not a general rule!!!)

I'd rather have one of the OS BIO fuel engines. They make a .55 a .75 and 1.20 now.

Sorry Pe, you lost me. Is the occarino type the same as the MVVS "silent muffler"? Is the "side dump muffler the same as the standard muffler that comes with the engine? What sort of aftermuffler are you referring to? Thanks again,
Jim

the side dump type is item 3225 (also called standard muffler, it has an occarino shape)
The side dump with added muffler is 3225A
The black tuned side muffler is 3243
The black tuned rear muffler is 3244.
Check them out on [link=http://mvvs.nl]my web pages[/link]