Longest engine evolutions

[Bryan]

Been reading about the Buick 215 V8 and how it evolved in so many directions over four decades. Not just the well known evolution into the Rover 3500 and it's Leyland P76 and Range Rover derivatives, but also into the Repco Brabham F1 and Repco Leyland F5000, Traco Oldsmobile, and TVR and Morgan. And within Buick, it evolved into the iron block 300 V8, and with two cylinders lopped off, became the 3.2l V6, sold to Jeep, bought back by GM, eventually forming the basis for the Formula Holden 3.8 V6.

Apart from the Ford and Chevy V8s, are there any other engines with such a diverse or convoluted development history, that have been used in motorsport?

Perhaps the Ford Kent, being the basis of the Lotus Twincam and Cosworth FVA and BDA?

The BMC B-series engine might be a contender - evolving from a 39bhp 1.2l pushrod in the 1954 A40, into the 1.7 and 2.0 OHC O-series in 1978, then into the 16v M-series in 1987, and finally into the 200bhp turbo 16v 2litre T-series in the 220 Tomcat. Another BMC engine that had a long history was the E-series from the Maxi, which made it's first competition appearance in the 1970 World Cup marathon, competed at Bathurst, evolved into the South African Land Rover R-series, and after tweeking and adding twin Webers, became the 1600 S-series in the MG Maestro.

No doubt there are a few others out there.