True... but false. Seems to be a lasting urban myth that the glow plug remains heated after start cycle and engine warms to operational temp.
Very old diesel engines used a blow torch.. or other means to get preheat into the cylinder to assist ignition for starting.... later.. the electric glow plug does the same thing. Once engine temp at the combustion chamber has risen to the point that compression combustion can be sustained such devices are no longer required. Many things can be used to raise combustion temperatures to start a diesel... One is to use gasoline.. in early large diesels.. the start cycle used gasoline on one or two cylinders to start the engine and "crank the other cylinders" which raised combustion temperatures in successive power strokes until the cylinders were all hitting... then the "start cylinders" were switched to diesel... Some used blow torches... or coal fires and the heat was drawn into the cylinders to "warm them up" from dead cold... but in all cases.. once the engine ran on it's own... on diesel... the external heat was removed. Same for glow plugs... Mercedes glow plug system works on the same principle... glow to start.. even then the glow plugs cycle on and off to keep from overheating... and continue for a time until the temp sensor [check your wiring diagram for what does what] tells the glow circuit the engine has reached a sustainable operation temperature... On a really cold morning... with a bad glow system.. a diesel is a B*#&@#ch to start.. I've used heat guns, hair dryers, and other warm air tricks, like a rubber hose from the exhaust of a gas engine to pump into the intake of one to get a start.... Ether.. the gas of death should only be used by it's self.. and sparingly. Its burn point is very low compared to diesel... and a shot will get a burn started... which then starts the engine burning diesel Or in the case of model airplane engine.... castor oil and alcohol serves the same purpose.. with a working glow plug... somethings.. FWIW, Grant... On Thu, Oct 4, 2012 at 6:18 PM, Jim Cathey <j...@windwireless.net> wrote: > engines - they rely on the glow plugs staying red hot from the previous >> combustion cycle for ignition. >> > > I would say no, they are not CI. Proof? Try to start one > without a battery on the GP! Compression ain't enough. > > GP engines are very old. Many tractor-type engines of > 100 years ago were that way. Heated with blowtorch, etc. > > -- Jim > > > > ______________________________**_________ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives > http://www.okiebenz.com/**archive/<http://www.okiebenz.com/archive/> > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/**mailman/listinfo/mercedes_**okiebenz.com<http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com> > _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
