Another concept of IC engineering which has come full circle.
In recent weeks we have seen announcements of work with variable valve timing, advances in electronic control and various waste heat and hybrid drive trains for large 2 stroke plants. Again we see many old time principles which have reappeared after many years of dormancy. When fuel was inexpensive as compared to today's rates many of these systems, although increasing efficiency were considered too complex to merit their benefits. With the sharp rise in fuel costs and the ever increasing
restraints of environmental regulation the books are being reopened and development of new systems is again warranted.
When we look at 2 stage turbocharging we see that it has been employed on 4 stroke plants, primarily high speed units for years. It was not until Mitsubishi applied this principle to it's UE engine that large 2 strokes were shown to benefit from this technology. Mitsubishi has always been ahead of the curve as an independent designer of 2 strokes. Another Japanese engine builder Fuji worked extensively with variable valve timing and hydraulic valve actuation back in the 70's on it's 4 stroke engines.
We can thank Rudolf Diesel and the Belgian railway engineer Walschaert for the roots of these simple principles which today combined with the sophistication of electronics result in the increased efficiency of the diesel engine. When I read the daily headlines in marine engineering it makes me garner further appreciation for my Grandfather's words "You were born thirty years too late" during a pier side chat on a cold April morning more than 50 years ago.
Photo: Courtesy of Wikipaedia