[mikeyg36]

Originally Posted by DGthe3

There have been some W9 engines (3 banks of 3) but I don't believe any of them were American. There might have been some inline 9's as well, but I don't think so. I think there are some marine diesels with a strange number of cylinders (inline 11's, for example) but as far as I know nobody has built one for the auto industry.

The first problem with something like an inline 7 is that you'd have to have a cylinder fire every 102.857142857... degrees (or half that if you're doing a 2 stroke). Compare that with a 6 or an 8 (V, flat, or inline) where they have to fire every 120 (6) or 90 (8) degrees. Which one is easier to get the timing right on? On top of that, you also end up with weird vibration patterns with inline engines that have an odd number of cylinders. Inline 4's, 6's, and 8's can be balanced quite easily (in fact, a straight 6 is perfectly balanced on its own). But a 3, 5, 7, or 9 has a much rougher time of it.



The rotary engine was created by Felix Wankel, a German living in Germany, while working for a German company.

Wankel engines and rotary engines are two different things; All Wankel engines are rotary engines but not all rotary engines are Wankels.