The Napier Deltic was based on the Junkers Jumo aircraft diesel engine developed before World War Two. The Jumo had one bank of 6 cylinders and two crankshafts, so the Deltic was much more economical of crankshafts and crankcases. Apparently Napier took out a licence from Junkers before the war and acquired the technology but didn't go into production.
The Jumo by report was suited for running at a constant throttle setting but couldn't take the variations in power needed for most military operations. Apparently the piston which governed the exhaust ports and the cylinder area around it tended to get too hot. It was used in the Junkers JU 86 bomber-transport (and in the JU 86P high altitude reconnaisance version where the suitability of the diesel for turbosupercharging came in extremely handy; Paul Wilkinson's "Aircraft Engines of the World" for 1944 says it could maintain sea level power to 32,000 feet) and in Dornier patrol flying boats. I've read casual references to the Deltic having maintenance problems. There is a British book on the history of Napier ("The Napier Story?") which may have more information. L. J. K. Setright's "Some Unusual Engines" may have something on it; my copy is long gone and my memory is dim. British engineering journals of the 1950's will likely have information about the Deltic. Before the war Napier was apparently badly managed; this caused problems with the Sabre aircraft engine. During the war the company was taken over by Rolls-Royce due to the need to get the Sabre in reliable service and in production. I've read that Napier had lathes at the time that were 100 years old. After the war Napier dissipated a lot of effort on the Nomad compound diesel aircraft engine (which never went into production or flew in a prototype aircraft) and the Eland gas turbine propeller engine which saw very limited but not satisfactory service, and the Naiad helicopter gas turbine, which I don't think went into production. I get the impression that bad management continued, at least as far as management focus went. Doug Woodard St. Catharines, Ontario, Canada On Fri, 1 Jul 2005, Greg Harbican wrote: > Today while researching PT boats of WW2 and their younger cousins, the PTF's > of the 1960's, I came across a engine called the Napier Deltic. > > I was very intrigued with the idea of a high speed 2 cycle diesel, that used > opposed pistons. > > http://www.ptfnasty.com/ptfDeltic.html > http://www.ptfnasty.com/ptfdelticoperation.htm > http://www.intertrader.net/ptfdeltic.htm > > > If I understand correctly, they may be a bit more efficient than standard > diesels, but, because they were so unorthodox they are somewhat obscure. > > Does anyone have any knowledge of, or first hand experience with these > engines? > > Greg H. > _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/