hp79

Hi,

I am installing a 58 pro engine and have to pay special attention to the noiselevel, which damper would be a good choice, when noise is a special concern at my local club.

Would the 3204 canister be a good choice, or should i go for a 4 chamber krumscheid can instead. ?

What would be a good size prop to start out with, im thinking in the lines of an Engel Super silent carbon prop 24X12 (2blade), am i totaly wrong here ? (still with noise in mind)

What about mounting, is it adwisable to use a rubber motormount ( something like hydromount), or just bolt i directly to the fuse, ( its a glasfiber fuse)?


Best regards


Henrik


WWW.OEMF.DK

DarZeelon

Henrik,


The Krumscheid four-chamber will probably be quieter than the #3204.
But in the power department, the MVVS canister will give significantly more.

hp79

Im aware that the best result would be the 3204, but I have to bring it down to about 82 Db 10 meters away from the model, with full open throttle.
Do you have any noise (db) measurings on this engine with the #3204 canister.
?
It would be fun to get the full potential out of this engine, but due to the noise-restrictions at my field, i have to take the element of noise into considderation.
Here in Denmark there has been several clubs who have had to close, due to nabours who did not appriciate the "delicate" sound of a large combustion engine. (unfortionatly)

pe reivers

I am currently testing my new line of MTW Mufflers. So far, I found them more powerful and more silent than 3W mufflers. Give me a week or so and I will know more.
These mufflers gain glowing reports in Germany, where there also are noise restrictions , we have 80 dB at 7 meters, so you are not very bad off.
In general, for low noise go with larger pitch. This will allow a high engine load with lower tip speeds. The topic is quite complicated, and I have already answered it to great length in a different thread. I forgot which one, so you will have to search.

Found it, look at [link]http://www.rcuniverse.com/forum/m_4447999/anchors_4449562/mpage_1/key_/anchor/tm.htm#4449562[/link] , post number 8

hp79

hi PE

Thanks for the link, i will await you tests of the MTW-silencers before i make my final decision.

Will the results be posted on your homepage ?

henrik

pe reivers

I will probably dedicate a thread to the results on my forum [link]http://prme.nl/forum/[/link] , so the disclosure can be open to comment and questions.

hp79

Hi Pe,

How is the testing of the MTW-silencers coming along ?
By the way great forum you have there, with lots of valuable information.

Best regards Henrik

pe reivers

I am about done testing the TD75 series on the 45cc and 35cc engine. This was more work than I, a one man's business, cared for because it included header length tests. Noise level (45cc) on a 3W 22x11 is very pleasant after I routed the carb intake into the fuselage.
No noise measurements yet. The normal grass surface now is like concrete after the drought, which adds about 3dB. Not good for type testing.
As soon as I get some time I will publish the data, and continue tests with the 58cc and 26cc engine.