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Although Toyota pulled out of Grand Prix racing soon after the end of the 2009 season its naturally aspirated, 2.4 litre V8 remains one of the engines homologated for Formula One under the ongoing engine specification freeze.
Produced by wholly-owned subsidiary Toyota Motorsport (TMG) in Cologne, Germany, it is a state-of-the-art Grand Prix engine, which was highly competitive last year as witnessed by its pole at Bahrain and second-place finishes in Singapore and Japan. The 2009 Formula One engines produced in the region of 735 bhp. In fact, under the 18,000 rpm rev limit imposed for that season, the Toyota RVX-09 V8 is an ideal engine, having a well-tailored bore size (no alteration of bore has been possible since the first stage of the current freeze was implemented for 2007).
The 2009 RVX-09 V8 is derived from TMG’s 2005 3.0 litre V10 engine, which had a 96.8 mm bore and ran to 19,200 rpm. With the enforced switch for 2006 to 2.4 litre V8 engines maintaining the same 300 cc per cylinder, TMG did the same as its rivals and strove for higher engine speed. The new rules for 2006 were confirmed so late, however, that for logistical reasons TMG kept the existing bore size, together with the established valve sizes, angles and so on.
Essentially, rather than a complete rethink, TMG’s G/H-spec V8 of 2006-9 is an evolution of its 2005 F-spec V10 but with two fewer cylinders. Not only did the bore size remain the same but – aside from the loss of two cylinders – the block, heads and sump were of the established pattern, the timing drive was identical, and so on. Mind you, the new rules imposed many parameters (see sidebar: Formula One 2.4 litre V8 regulations) while a 90º bank angle, flat-plane crankshaft V8 is fundamentally different in operation from a V10 with the same bank angle.
Nevertheless, from the outset, the basic concept had been to produce an engine to the 2006 rules that didn’t stray too far from established practice and then to design a more optimised V8 based on lessons learnt from that exercise. Indeed, initial investigation for the V8 project consisted almost literally of chopping two cylinders from an existing V10, fitting a new crankshaft and running the resultant experimental engine on the dyno.
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