not to start an argument but what does the availability of something have to to with it being the best ever?
What about the BMW M10?
The BMW M10/M12 was an I4 piston engine produced from 1961 to 1987. Displacement ranged from 1499 cm3 to 1990 cm3.
The engine was designed by Baron Alex von Falkenhausen, noted engineer and race driver. He was asked to design a small-displacement (1.3 L) engine, but felt that this would be insufficient for the company's future needs. Therefore, he designed a block that could be expanded to 2.0 L and delivered it at 1.5 L.
The design was very successful, with over 3.5 million produced, and it served the company for over 20 years.
The M10 engine is also one of the most successful engines in racing. Starting with the European Touring Car Championship, it was also used in Formula 2, then the Deutsche Rennsport Meisterschaft, were it was turbocharged by Paul Rosche according to FIA Group 5 rules.
The M10 block went on to Formula 1, winning the 1983 championship for Nelson Piquet and Brabham - something which very few 20 year old road car engine designs accomplish. The same applies for the rise in power, twenty-fold from 75 hp to about 1500 hp.
The BMW S14 engine for the first BMW M3 was based upon the M10 block. In the M3, the M10 is still winning races today.
Or the BMW S14?
The BMW S14 is a 2.3 L (2302cc) DOHC 16-valve I4 piston engine. It was used in the E30 M3. The S14 is essentially a BMW M10 engine block with a M88/S38 DOHC cylinder head (minus two cylinders). It has four separate throttle bodies. It developed 195 PS (143 kW/192 hp), or 200 PS (147 kW/197 hp) without a catalytic converter. A special tuned model, the S14 EVO producing 20 PS more. The 2.3 L version has a 93.4 mm bore and 84mm stroke.
Variations of this engine included a limited-edition 2.5 L (2467 cc) Sport Evo for motorsport homologation requirements, and a de-bored (89 mm) version for the 320is, a more affordable sports model made specifically for the Portuguese and Italian markets. The 320is can be quickly distinguished from the E30 M3 by the absence of flared wheel arches.
people have seen over 400hp n/a