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RE: Diesel engines
Posted by: Tom Iwanski ()
Date: May 01, 2001 08:56PM

<HTML>Hi Steve,
Two stroke General Motors diesels up to a certain size did use Roots type blowers. It was my understanding that most, if not all two stroke diesles relied on blowers (superchargers) for proper exhaust gas scavenging. (I really don\'t know much about the Fairbanks Morse, however) The Roots blowers were considered postive displacement air pumps with two or three lobes on each blower shaft. They worked kind of like an egg beater in that the lobes meshed to compress the air, similar in concept to a gear type pump designed for fluids. They were typically driven off the crank/cam gear train but used a special sized gear to attain the rotational speeds required for optimum boost pressure (usually 2:1 or 2.1:1)

Turbochargers were added to these GM engines at some time after the war (or maybe late in the war) The turbocharger would supply pressurized air to the intake of the blower, that would then compress it further. It was later discovered that at high loads (when the turbo is delivering max boost) that the blower wasn\'t needed. So GM devised a bypass valve that equalized pressures on the intake and output sides of the blower. This essentially allowed the blower to freewheel, reducing its parasitic load to almost nothing, while the turbo supplied all the boost.

Regards,

Tom</HTML>

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Subject Written By Posted
Terrific Submarine weekend Kris 04/29/2001 05:59PM
RE: Terrific Submarine weekend Steve Cooper 04/29/2001 09:40PM
Diesel engines SuperKraut 04/30/2001 05:49AM
RE: Diesel engines Steve Cooper 04/30/2001 11:58AM
That\'s the one! Kris 04/30/2001 12:18PM
Not quite Steve Cooper 04/30/2001 03:46PM
RE: 2 cycles? Joe Brennan 05/01/2001 07:21AM
RE: 2 cycles? Tom Iwanski 05/01/2001 12:18PM
RE: 2 cycles? Eric Goethel 05/01/2001 08:42PM
RE: Fairbank Morse Joe Brennan 05/02/2001 06:01AM
RE: Diesel engines Rainer Bruns 04/30/2001 08:30PM
RE: Diesel engines Tom Iwanski 04/30/2001 09:32PM
RE: Diesel engines Rainer Bruns 05/01/2001 01:23AM
RE: Diesel engines Steve Cooper 05/01/2001 12:10PM
RE: Diesel engines Rainer Bruns 05/01/2001 02:12PM
RE: Diesel engines Steve Cooper 05/01/2001 06:12PM
RE: Diesel engines Rainer Bruns 05/01/2001 08:17PM
RE: Diesel engines Tom Iwanski 05/01/2001 08:56PM
RE: Diesel engines SuperKraut 05/01/2001 07:52PM
RE: Diesel engines Eric Goethel 05/01/2001 08:57PM
RE: Diesel engines Tom Iwanski 05/01/2001 09:12PM
RE: Diesel engines Rainer Bruns 05/01/2001 11:49PM
RE: Diesel engines Tom Iwanski 05/02/2001 12:50PM
RE: Diesel engines Rainer Bruns 05/02/2001 03:07PM
RE: Diesel engines John R. 05/02/2001 01:29PM
Fuel prices SuperKraut 05/03/2001 07:10AM
RE: Diesel engines Tom Iwanski 04/30/2001 12:29PM
RE: Terrific Submarine weekend Sean 04/30/2001 12:43PM
RE: Terrific Submarine weekend Frank Blazich 05/01/2001 11:24AM
RE: Terrific Submarine weekend Sean 05/03/2001 12:57PM
RE: Terrific Submarine weekend Angela 04/30/2001 11:42PM
RE: Terrific Submarine weekend Rainer Bruns 05/01/2001 12:39AM
RE: Terrific Submarine weekend Kris 05/01/2001 03:16PM


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