These engines are commonly called hit and miss engines. A governor suspends the spark above a certain speed. With no load they will free wheel several cycles between receiving a spark and firing. Under load they will fire on every cycle.
Jeff -----Original Message----- From: Stephen A. Lawrence [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 15, 2008 8:35 AM To: [email protected] Subject: Re: [Vo]: Old engines I've heard quite a number of somewhat similar ancient one-lunger engines -- they're a staple at county fairs in New England (and Ottawa, it seems) -- and they have a very distinctive sound. Do you know why they sound the way they do? It appears, from the sound, that they're actually performing a large number of full rotations between cylinder firings, but that doesn't to make a lot of sense to me, unless there's some kind of governor or speed control that only lets fuel into the cylinder when the rotation rate drops low enough. Is it really what's going on? Or is the "pouf" something else, backfiring maybe, that I hear every, what, half dozen or dozen turns? Certainly it seems like the "Pouf" sounds come much farther apart than I'd expect for a four-stroke. Horace Heffner wrote: > Some here will remember the great vortexian (yep I use the term > vortexian here because he graduated from the U of Houston) Frank > Stenger. Here is one of his latest achievements: > > http://www.youtube.com/watch?v=IF7NxVcg3jY > > It is difficult to believe what a rusted mess of damaged parts this > antique oil field engine came from. This is real tour de force for any > mechanical engineer, a work of art, but probably one only a connoisseur > of such things can appreciate. The sound signature of these things > appears to be highly varied and unique to a machine. It is quite > amazing to me how many of them are being restored and can be viewed on > YouTube. > > Best regards, > > Horace Heffner > http://www.mtaonline.net/~hheffner/ > > > >
