V4 or V6 is another issue to look into aside from direct injection.
The V6 has to be 120 degrees for good balance, the 4 has to be 180.
Shouldn't a flat 4 be a better prospect than a V layout?

xpensive wrote:However, I cannot see a V-4 either, when this would have effectively zero road-car relevance for the manufacturers.
ringo wrote:V4 or V6 is another issue to look into aside from direct injection.
The V6 has to be 120 degrees for good balance, the 4 has to be 180.
Shouldn't a flat 4 be a better prospect than a V layout?
tok-tokkie wrote:ringo wrote:V4 or V6 is another issue to look into aside from direct injection.
The V6 has to be 120 degrees for good balance, the 4 has to be 180.
Shouldn't a flat 4 be a better prospect than a V layout?
MotoGP has V4s in Honda, Ducati & Suzuki. They use 360° crankshafts which give 90° 270° 90° 270° firing intervals referred to as 'Big Bang' as against 'Screamer' with 180° cranks with even 180° firing gaps. The 'Big Bang' is really 2 long bangs and 2 longer pauses. It makes a more rideable bike as the rider has better physical feedback of the roadholding during the pauses between bangs - at least that is the current belief.
The Yamaha I4 has a 90° crank giving the same firing sequence as the V4s.
An interesting article on the balance of twin cylinder engines = half of a I4 and applicable to the Yamaha engine: http://www.xs650.org.au/smoothness.htm
xpensive wrote:Don't forget the 1990 Subaru flat-12, not that it xactly set the world on fire. But no, with today's quest for a slim bodywork at the rear, a flat something would not be very practical.
However, I cannot see a V-4 either, when this would have effectively zero road-car relevance for the manufacturers.
How about a mildly boosted, to 0.5 Bar, and rev-limited to 12k, 2.4 V8? This should make for about the same power as today but give an engine that would last for a season, while maintaining the multi-cylinder image?










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