Porsche 919 LMP1 - Why a V4 petrol?

[WilsonLaidlaw]

The pictures from Le Mans showed the 919 was vibrating so much, the camera could not focus. A V4 engine just seems wrong to me. It is neither in primary nor secondary balance and if you try to cure that with staggered crank pins, you end up weakening the crank and funny firing intervals. I would not be surprised if they replace it with a 2 litre V6 in due course. This would also reduce the length of the very long looking gearbox casing. I gather the vibration was also bad enough to damage the interlinked suspension, which slowed the car before it finally failed. The V6 has the additional advantage of even firing intervals which reduces pulsing loads on the turbocharger.

[NJH]

Interesting points Wilson although the last point is I believe incorrect. Trying to put the firing pulses from 6 cylinders into a turbo causes pulse interference leading to twin turbo designs or designs with a split turbine in-feed i.e. each exhaust branch is kept separate all the way into the turbine to stop the pulses interfering. At least that is how some old books describe it anyways.