At 10/22/2004, you wrote: >If you build an expansion chamber type exhuast for your small gas >engine you might even gain some power on top of quieting it down,
Expansion chambers help two stroke engines. A straight tuned exhaust is what works on four strokes. For a Briggs it is about 12 inches long. You are trying for a wave to be reflected off the opening and to arrive back at the exhaust valve when it is opening. Two strokes do not have a sharp an exhaust pulse as four strokes so the expansion chamber exhaust neck provides the sudden change needed for wave reflection. The engineering of exhaust acoustics is extremely interesting. Don Bowen Awl Knotted Up Woodworking Valley Center, CA http://www.braingarage.com [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/z1TolB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To reply to this message, go to: http://groups.yahoo.com/group/Boondocking/post?act=reply&messageNum=7361 Please do not reply to this message via email. More information here: http://help.yahoo.com/help/us/groups/messages/messages-23.html <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Boondocking/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
