ex Budd man wrote:Why is EMD going to four stroke engines?Where have you been. EMD dabbled in 4 stroke design 15 years ago and seems very happy to continue with the hugely successful 710 series. I would like to know what the scientific basis is for this prejudice against 2 stroke diesel engines other than religious reasons.
Thankx for the clarification. I noticed that Detroit Diesel is no longer building two strokes either............. Gee you look away for a minute and someone changes everything!mtuandrew wrote:Most two-stroke engines don't (and can't) have fully variable valve timing, which can help control emissions and increase power for a four-stroke, and don't burn their fuel as completely as a four-stroke engine. They're also more difficult to fit with pollution controlling fixtures like exhaust gas recirculation.
DutchRailnut wrote:Piston rings scavenge oil from cylinder walls, when those rings pass the airbox ports, the oil will get in combustion cycle.Any engine will draw oil past the rings if they are worn, two stroke or four. One would think since constant positive pressure in the air box would lessen this effect. I may be barking up the wrong tree here. Any EMD techs care to share?
This why on EMD's oil is not changed, its just added.
DutchRailnut wrote:not talking about oil getting by rings, but rings passing port, dumping oil strainght into airbox.You said the 'B' word, go wash your mouth out.
As for SEPTA maybe they change oil cause their a bus company.