mvallyman

My Feedback: (32)

Im running a $100 TBM canister and Vess 22A prop on a DL 50 about 6900 RPM max. Not sure what Db its making but just wondering by your experience what canister typically runs quieter. The plane EG MX2, runs well, I just like it to be quieter.

av8tor1977

My Feedback: (6)

This doesn't directly answer your question, but you could put a bit more prop on it and get it down to around 6500 rpms. Also, people don't realize how much noise the intake makes, especially on a two stroke engine. It is significant. If you have room, try adding an air filter. It would surprise you.

Here's an easy experiment. If you have a weedeater or leaf blower, unhook the spark plug, give it full throttle with the choke off, and pull the starter rope a few times. Then take the air filter off and do the same thing and note the noise. Big difference. Multiply that by thousands of rpms.

AV8TOR

MTK

Don't know about the TBM can. I assume it is aluminum. Any aluminum muffler will be tinny sounding. Even if it was afull blown pipe it would be louder than an equal composite pipe.

A couple things that will make the powerplant quieter with the existing canister, first I suggest that you try a 3 bladed prop such as the Mezjlik 20x12 carbon. Then, a soft mount would definitely help.

My 50cc class set-up uses a DLE55, ESComposites 55G pipe, DA return to center flexible header, the afforementioned Mez 20x12 3 blader and a soft rubber isolation mount similar to Hyde mount. It is very subdued on the ground and electric like quiet in the air, with power to burn.

One of these days I will post a video to show all what I've done and explain the individual components I included in that package. The components are pretty much off the shelf including the soft mount (from Hyde or from me) and are simple to duplicate......More info, contact me direct

earlwb

Have you measured your noise DB levels with the stock muffler and with the canister muffler on the engine?
If you have a smartphone, they have several DB meter apps you can download and use for the smart phone.
One thing is that not all of trhe canister mufflers are created equal. The cheaper ones tend to be more loud than the expensive ones, and vice versa too.

BarracudaHockey

My Feedback: (11)

Yes, Pro-Flo cannisters are high quality, improve transition, and are quite quiet.

pe reivers

Quite quiet, but not quite. They also are lacking a bit in top power. They make up for that in the smooth power application.

mvallyman

My Feedback: (32)

Thanks guy's, all of these are valid factors. I havn't seen much in air filters for these engines.
I would like to see what you've done as far as soft mounting mattk.
Pe, how much rpm off the top or percentage in power can the Pro-flo take from me? Is there another canister you would recomend? I dont think I can get much more than a 60mm Diameter can in the tunnel, maybe a 65mm.

pe reivers

On a DA170 the proflow was 250 rpm less than the same engine on KS95 (same prop)
To answer your question is nearly impossible. There are many good canisters in the market. For 45cc to 65cc, I like to use the MTW75 canister of 55mm diameter. Then it's up to your tuning the setup to make the best of it.
if peak power is what you need, use a tuned pipe, like MTW RE2

MTK

Earlwb,

I have never used the stock mufflers on any of these small gassies. All have been run on pipe from the start. But I have heard others running DLE 55's on stock muffler and they are very loud. I'd guess around 100 dB at 10 feet

My DLE55 set-up was measured using the AMA guidelines for pattern Aerobatics....measured once, over grass, at about 10 feet, downwind with a calibrated gauge (calibration source unknown). We got 91 dBA at full throttle with the Mezj 3 blader, but around 94 dBA with one of my carbon wood hybrid props 22x12 2 blader. So much for numbers

The proof was in the using tho...any powered modelflying at the same time as me drowned me out, even 0.40 cuin trainers.It was eyeopening proving that these engines don't have to sound like chain saws to work well.

BarracudaHockey

My Feedback: (11)

Pe thats true, but for 3d I'd rather have better midrange and transition over a hundred or so RPM at the top.

pe reivers

The following canisters that I know of have "flat" power curves for best mid range:
JMB
MVVS int 58
KS 94

I have never seen power curves for a proflow, but I could produce them if someone sends me a muffler.

earlwb

There were some pictures posted of where some people had cut in half some canister muffers to see what they looked like. The better canister mufflers tended to have a more thick shell and more baffles and passages inside that the cheap ones. Some cheap mufflers were just a hollow shell with a inlet and a outlet. But some other cheap mufflers didn't look all that bad on the inside but they had thin shells though and that may not help with noise reduction either.

MTK,  yeah the stock OEM mufflers can be quite pitiful for noise reduction. But it makes for a comparison with a canister to see if it is reducing the noise or not too.

WRK

My Feedback: (2)

Pe, does the MTW RE2 tuned canister still muffle the exhaust noise like other canisters that are not tuned?

mvallyman

My Feedback: (32)

I took a Db reading of the motor in question running a "no name" $109.00 china can from Troy Built Models, DL50 with Vess 22A spinning at 6800 RPM. Its producing 94 Db at 9 ft.
Does anyone know of quieter readings on a 50cc with a name brand can and or different prop?

Should I be taking the reading at a different distance to compare to some of your readings?

pe reivers

Yes. However, because there is more power to the propeller, prop noise will exceed muffler noise.

pe reivers

There is a discusion going on at the flyoing giants that answers all your questions:
http:*/forums/showthread.php?t=78235&pp=40#post1847581

mvallyman

My Feedback: (32)

Thanks Pi, Need to find out if another can will get me any quieter.

Rudolph Hart

At the risk of being ignorant and i usually am why can't we shortcut the op's original post by saying forget about noisey yukky sounding el cheapo two strokes and go with more instant grunt and a fourstroke??pussies

earlwb

Well the OP already has a gas two stroke engine. He wants to reduce its noise level even more. So having him switch to a four stroke engine in his plane would entail more cost. But even then the four stroke engine may not reduce the noise enough too. The propeller noise and airframe noise can contribute a significant amount of noise in addition to the engine noise. Besides a four stroke engine can be quite annoying too, for example, your neighbor deciding to fire up his gas lawnmower to cut the grass at 7:00AM Sunday morning.

Sure we could mention gas rc four stroke engines. But we are still limited in our choices yet. We don't have a four stroke engine to swap out for a two stroke engine in the 50cc displacement range. I would assume that for a 50cc gas engine we would need something in the 60 to 70cc displacement range as a four stroke engine to replace it and keep the power the same. The four stroke engines still tend to be down on power in comparison to a two stroke engine of the same displacement.

But we do have a three 50cc four stroke gas engines that one could likely use, such as the Kolm 50cc four single cylinder stroke engine (costs around $1600 US), and the RCS 50cc single cylinder four stroke engine (costs around $1200 US) and the Moki 50cc gas four stroke engine (costs around $1100 US). There is a good candidate with the RotoMotor 85cc twin cylinder gas four stroke engine too (costs about $1700 US). The Saito FG-57 twin cylinder gas engine might be another good candidate too ($1100 US cost). The problem is that the cost may turn off most people as one could maybe buy several gas two stroke engines for the price of one really nice four stroke engine.

If one can fly with a little less power, then there are some smaller displacement four stroke engines that one could choose, A NGH 38cc RC gas engine (circa $400 US cost), a OS 40cc RC gas engine (it should be coming out any time now), and a RotoMotor 35cc gas engine (about $800 US cost). Then there is the Saito FG-36 amd FG-40 gas engines (at around $800 US ). Some people have been pretty successful at flying 50cc size airplanes using the 38cc to 40cc gas engines in them already. But there are flyer preferences as to power preferred and their altitude from sea leavel as to how well this works along with the airplane used.

mvallyman

My Feedback: (32)

Good explanation earlwb, and as in one of the first posts, its a matter of the prop, muffler, carb noise and airframe.
I believe on mine my money will be most effective on the muffler, I just dont want to buy all of them to find out which one will work best.

earlwb

Yeah I think finding one of the better canister mufflers should do the trick.
In the past post # 8, in this thread here shows a really good one. But he didn't say which one though.
http://www.rcuniverse.com/forum/m_86...tm.htm#8645769

pe reivers

In Germany, glider towing competition rules are extremely stringent concerning noise. Their planes will not be heard if the wind force is a bit high. NO four strokes there, but low revving two stroke engines. The two stroke does have more grunt than a four stroke if set up properly.

Pelle Gris

I own a King 140 twin which is often used to power large tugs in Germany. It will run without problems when loaded down to 4000-4500 rpm, and then it´s very silent in the air.
My own engine spins a SEP "Wilga" prop at 4600 rpm, and even without having taken any sound readings of it yet, it does seem to produce very little noise.

Rudolph Hart

I was being a bit tongue in cheek(y) about fourstrokes because most of the guys i fly with use them too in all sizes gas and glow.Kolm also make a 67 single.We like the noise they make and the louder crackle you can get out of one the more bragging rights you have.Are noise restrictions that bad over there??

earlwb

Many club flying places in Europe seem to be very restrictive on noise levels nowadays. Even here in the USA many flying fields are more noise restrictive but it is like 100db limit or a 95 db noise limit. it is tricky and hard to get a engine under 92db easily.
I think you guys in Australia have it made so far, with all those wide open spaces, you guys don't even need mufflers. I bet you guys can still run a .60 engine sans muffler there too.