PRV in final version was also converted to 60 degrees. I believe this is engine Chrysler Eagles used. Bill Robertson #5939 >--- In dmcnews@xxxxxxxxxxxxxxx, "B Benson" <delornut@xxxx> wrote: > This has been on the list a couple of times but again, the reason an engine > is odd or even firing is because of the crankshaft design as related to the > number of cylinders and their degree of opposed separation. In the case of > the DeLorean engine it is six cylinders with two groups of three cylinders > opposed at 90 degrees. The most economical design for crankshafts in a 'V' > configured engine is to have a pair of opposed cylinders sharing the same > journal of the crankshaft. When you oppose six cylinders at 90 degrees and > have each opposing cylinder share a common crankcase journal the math works > out to the fact that one of these cylinders rotates the crankshaft more > degrees than the other. The firing order is configured accordingly. A more expensive > approach is to utilize a crankshaft with individual journals for each > cylinder which equalizes crankshaft rotation throughout all cylinders. > Unfortunately that creates more expense for the manufacturer and many have > adopted a less expensive approach with a counter rotating balance shaft > designed into the engines total configuration to counter the odd firing > scenario . This works out very well and results in a smooth running odd > firing engine. Since many V-6's were derived from 90 degree V-8's > (8 cylinders at 90 degrees do result in an even firing scenario) they ended up as odd firing. Newer V-6's have been been designed in 60 degree configurations > to allow the math to work out to even firing. > > Bruce Benson