+ TECH INSIDER

BT Sport’s Michael Laverty investigates the strengths and weaknesses of the configurations that rule MotoGP

BRUTE FORCE vs PERFECT POISE

‘The V4 has the lion’s share of MotoGP glory’

The thrilling battles at the opening two rounds of the 2021 MotoGP championship in Qatar raised the age-old debate: What is the ultimate fourcylinder MotoGP engine? Statistically the V4 has enjoyed the lion’s share of the glory since the 2012 move back to 1000cc, but if you remove Marc Marquez from the equation the outcome looks decidedly different and the inline four wins out. But four circuits overwhelmingly remain the domain of the V4: Brno, the Red Bull Ring, Sepang and Motegi. And they are all ‘horsepower circuits’. V4s can produce more bhp to MotoGP’s 1000cc limit than inline fours due to a number of factors – the shorter V4 crankshaft has fewer bearings, which lowers friction; it is stronger, meaning it can reach a higher RPM and the crankcase design has more efficient airflow which negates pumping losses. In terms of physical size the V4 is a longer design, so the power advantage demands a trade-off when you attempt to position the engine mass inside the chassis. An inline four is wider than a V4, yet both machines are actually a similar width due to radiator size being the determining factor as the cooling of such high power engines remains a huge design constraint. The trade-off between superior chassis and handling versus top power has never been more evident than during the opening races of the season where the Yamaha and Suzuki inline fours could swoop through the corners only to be blasted by the Ducati

V4s with their raw power, tamed via electronics and aerodynamics.