By aevald
Date 02-23-2008 00:30
Edited 02-23-2008 00:33
Hello again hjp4, not that this really matters, but the two-stroke diesels will not run without the supercharger that is on them, since they fire on every stroke the supercharger provides the charge of air for the combustion and the injector provides the charge of fuel to combine with this air. Due to the manner in which these engines are designed they do not have the ability to draw air into the combustion chamber, instead they use the supercharger to provide a positive pressure when the combustion chamber is exposed for this air charge. The ways in which they typically "hop these up" is through the use of over-sized injection nozzles and the addition of turbochargers in conjunction with the superchargers. Another thing that is unique to these, is their lack of intake valves, they only have exhaust valves, the intake of air is accomplished through porting in the cylinders. The cams in these engines control the opening and closing of the exhaust valves and the injection of the fuel by moving a plunger in the injector which in turn pressurizes this fuel charge to the point where it opens at a specific pressure(the injectors are supplied with low pressure fuel by a charge pump, I believe the injectors "pop" somewhere around 2000psi.) and generates a controlled spray into the cylinder at the same time that cylinder pressure has been maximized, causing combustion. I used to do a considerable amount of work on detroits in large buses, mainly 692's and 871's, always liked the sound of them, unfortunately can't say too much about liking them for a whole lot else, mainly due to the inability to gain access to work on them in a bus. Enjoy your "new" machine, sounds like that muffler is going to be an impressive one. Best regards, Allan
Be sure that You use a proper intake air filter and silencer. The roots blower screams like a siren if not properly muffled. My friend's boat uses a 2-71 on the large generator, that and the [4] 6-71's for propulsion makes it a noisy boat. We wear ear protection in the engine room, and in there You don't even hear much of the exhaust noise.