hyflyer9

We have pretty much the same Db levels rule here in Canada with M.A.A.C. so i do need to make this engine a lot less noisy for sure and i will keep you all posted on how i make out with the glass pack.

Joystick TX

Did you follow the AMA setup and guidelines for the db measurements?

hyflyer9

Like i mentioned the MAAC rules are the same full throttle at 3 meters or 10ft no more than 96db on soft surface and no more than 98db on hard surface.

Joystick TX

I'm not asking about the rules, I'm asking about the "method" of making the measurements; like the one mentioned in the #927 document It gives detailed information on what the Db meter setting should be, where it should be, etc. How the measurements are mademake a huge difference in the readings obtained.

It seems like 111db would be with no muffler at all.

Is that with the old or new model muffler?

hyflyer9

with the old muffler and will also have it rechecked to make sure it was done propperly and also will get levels with the inserts and then will do levels with a glass pack if i can figure out how to make it that is. I do know that i need to get the sound levels down and i don't want to be loosing a lot of power as this War Bird weigh's in at 18.4 lbs and this is just the rite engine as it provides a good scale power for this plane .

Joystick TX

It would be great if the db measurements were more of a science than an art, but that is not the case. There are alot of variables that can make the reading vary from day to day and plane to plane.

We have about 200 club members and about 10 to 15% of them show up each weekend. One thing I've noticed is that if a plane engine is actually loud, no db meter is required, the peanut gallery will detect it as soon as it takes off.

opjose

The first day I brought out my Syssa, I was told to "change the prop, the engine is too loud.".

I mentioned that the noise was NOT from the prop, but from the almost non-existant muffler ( it's practically a straight exit after all ).

I was told, "no it's the prop".

The next time out I installed the tone inserts. I was asked if I had changed the prop because the plane was now relatively quiet.

Nope, but with the engined tuned for no inserts, adding them greatly dropped power output.

I'd imagine a canister muffler is a better solution.

Has anyone found a header that will fit this engine?

Thanks.

hyflyer9

Something i am working on to get this engine less noisy without loosing a lot of power .
#1 I have done the modification to make sure that it stay's on tight
#2 Before i reinstalled the muffler i have cleaned all the paint off and made sure it was nicely cleaned andgavethe entire mufflera light coat of high heat RTV silicone including a light coat on the inner lip of the back plate to cut down on vibrations and to insure that it has o good tight seal .
#3 I put the tone inserts in my bench vise and drilled them out using a step drill bit to a 9/16 hole i then made sure that the holesare very smooth using a piece of 400 grit emery paper to insure a smooth flow of exhaust. And as this engine is in a War Bird and inside of a cowl i am not to worried about how the muffler looks as long as it is not noisy and still puts out the power my War Bird needs .
And sometime later this week i will get a chance to test it and i'll keep you all posted to how i make out and i will include some db levels.

Joystick TX

I saw thatthe RTV coating was used before, I don't know how much difference it made. The "soft mount" from Hyde, or made per MTK's instructions, may make more difference.

hyflyer9

Another reason why i use the RTV is that it Deadens the sound down and takes that tinny sound of the metel away.

tele1974

I am going to start devising a method to install a glass pack in this Pitts muffler as soon as I have it removed. I am also attempting to find a perforated steel tube smaller than the stingers to pack glass around. The back of the Pitts muffler is removable so I am thinking a layer of glass their too with a steel mesh over lay.


Edited by mooderator

hyflyer9

tele1974 Please keep us up to date on how you make out with that and if you can please post a step by step of your modifications
Thank you.

Edited by moderator

tele1974

Cant tell you because the forum doesn't let you type it in. Must be a bad word around here!). Funny.

Try this site.

http://www.flyinggiants.com/forums/s...ad.php?t=31705 - You'll have to copy and paste because the link feature is doing a redirect for some reason.

w8ye

My Feedback: (16)

Patrick,

Why don't you just post the actual infformation here on this forum?

JeffinTD

I kind of wondered about quieting this thing down myself.

I was thinking of attaching some type of high temp gasket material to the back plate of the muffler, and doing something to the outlet tubes.

Maybe take a piece of tubing the diameter of the inner hole on the tone insert and cross drilling holes in it, then braze it to the tone insert, wrap it in glass pack, tied on with some safety wire...

tele1974

That is exactly what I was thinking about doing Jeff. Can you fabricate these up for us as long as they are working. I don't have the ablity to braise.

Slow and Steady

I agree with the recover comment. That is one beautiful plane. By the way, the new muffler seams alittle more quiet. But almost the same. There are no baffles in the new muffler and the muffler box appears to be slightly larger. By the way, I flew both mufflers with the inserts.

tele1974

I missed the gasket material on the back plate idea.... Excellent idea!!! Or how about some layers of fiber glass cloth covered with a wire mesh over the back plate sandwiched between it and the muffler body edge. And layer in some RTV to seal the edge and trim the excess off once its bolted back together. Just a thought. Another idea I had is to install some 90 degree turbo tube on the outlets to get it away from the fuse and wing. I don't know if that would really change the sound much thou.

MTK

Take a look here http://www.rcuniverse.com/forum/m_92...m.htm#10160897

Everything you wanted to know about setting the Syssa up for tuned exhaust

MTK

PaTRICK,

The comments you will hear are the same I've been hearing the past 3 years running my gassies in contests. My latest effort uses the OS33GT and same ESComposites pipe I've been running on the SAP. Truly a beast of an engine, turning electric sized props, 20-21" diameter. Quiet, efficient running, getting about 13 minutes on 8 ozs avgas

Joystick TX

I took the engine out of my GSS today to check the carb filter screen and the muffler screws. Everything was okay. Should be good for another 50 hours or so.

I did add some foam material, the typethey use between the truck bed and the camper shell, to the inside of the cowl to see if that makes any difference in the noise level. Will check that when I fly tomorrow.

opjose

Wow thanks for the link!

Joystick TX

I can't tell that the foam in the cowl made any difference, so out it comes.

bipeflr

My Feedback: (8)

Flew my Rascal 110 today with SYSSA 30. Everything went great except the wind. Actually landed and was taxing back crosswind when wind picked up the Rascal stopped then weather vained into wind. I had the flaps down 1/2 and the thing actually lifted off and set down. Decided that was enough for today and packed it up while everything still looked new. That was third flight of the day and I probally was to be my last flight anyway but that gust made it a no brainer........Jim

Joystick TX

It is best not to use flaps with a high wind; same as in the "real" planes.

That should be a great engine/plane combination and a lot of fun to fly.

Glad you had some good flights and nothing fell off or broke.