flyrotary@lancaironline.net Mailing List Archive

Kelly,

I think what your referring to is exhaust augmentation whereby an exhaust tube runs into another open tube, creating a negative pressure sucking in air around the front end of the larger open tube. This is very successful with extracting air from the cowl - however it won't suppress sound, most likely it make it louder with sound waves escaping through the front open end.

If I understand you correctly.

George ( down under)

Lynn,

Another thought.............What do you think an "Extractor" system (In my "Delta's" case

one on each side of the bottom "V") consisting of large diameter tubes (5-6" ?) exiting

behind the cockpit with 2" tubes down the middle and open to forward motion and prop

blast would do to noise level ??.............

--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold

-------------- Original message from Lynn Hanover <lehanover@gmail.com>: --------------

Lynn,

I would like to see a drawing and I am sure others of the group would also !!.............I

know this is splitting hairs but I am planning on splitting my exhaust after the collector to two

mufflers (no good reason other than the Dyke Delta bottom skin has a "Keel" shape (V)

and I want to keep the bottom symmetrical with a muffler (recessed with cooling air) on each

side of the "V" ) and I wonder what size you would use from the 2.75" to branch off to the mufflers ??.........

Again Thanks,

Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold

The single pipe would about 5.9 square inches. A 2" tube would be 3.14 square inches. So I would use 2 inch tubing. Most modern V-8s have a combiner "X" fitting in the center of the two pipe system. It produces lower back pressure and a less harsh tone.

I will make some drawings.

Lynn E Hanover