Comment Re:Innovation! (Score 1) 525
A V allows you package more displacement in to smaller overall volume or to have less car to package around given in engine. Weight savings from a V engine boosts handling performance and economy. Yet an inline engine will be cheaper than a V, due to one, block, single manifolds, two camshafts instead of four.
Since a v engine has twice as many heads how can it possibly weigh less or have more displacement for it's size?
V engines don't have the length of an inline engine, and are more cube shaped which tends to suit application to more engine bays.
Difference in power may come from firing order, and the path intake charge and exhaust gas take and a small reduction in friction in a Inline 4 or 6. Inline 6s can have a good cross flow set up for top end power when mounted longitudnally in a front engined car (short straight intake runners and 6 into 1 headers, make a good turbo platform. BMW, Nissan and Toyota have exploited this to great effect in racing and in road cars. Aftermarket Nissan Skyline motors with 6-1 turbo manifolds make whopping power.
I don't think I've ever seen a non-cross-flow v-engine. They're at least as suited to a cross-flow head as an inline engine.
Turbo engines are "suited" to 6-1 manifolds because there's very little advantage in tuning the exhaust of a turbo'd engine. The 6-1 manifold is chosen because of this and because it takes up less space. If pulse tuning was any use on a turbo engine, they'd all be 6-2-1 as in an n/a application you could tune the engine to produce torque as the turbo spools.
I'd also wager that Skylines make whopping power because of the "whopping" turbo.
In the end, V8s rose to greatnews because it was probably the best balance between a number of cylinders, dimensions, displacement etc. A four cylinder block is about as long as you want to go. Big displacement engines need a greater number of pistons to stop the piston speeds getting out of hand along with smoothness reasons. Eight cylinders is just right, for big power or a big engine.
Nonsense, you can counteract piston bore with the stroke of the engine to have whatever speed you wish. Eight cylinders were chosen probably more because this leads to a more suitable ratio between engine dimensions.
A inline 6, and a 90 degree V12 and a boxer six are probably the three ideal engines, having perfect balance. The greatest engine of them all on the balance of all considerations, including, cost, complexity and packaging is the inline four. That's why V8s are made out of two of them:
Wrong again. An inline 6 has primary and secondary harmonic balance - about as good as any engine could hope to have, but not perfect. A boxer 6 does not have this, usually a boxer is chosen for a low centre of gravity/space saving to slap a bunch of turbos on top. A v12 has the same balance as an inline 6 no matter what the angle is, 90 or otherwise. It's a little smoother because of the increase in fires per revolition.
American V8s most often really are just two inline four engines stuck together. Right down to the split-plane (cross-plane) crankshaft. Yes there are hack mechanics who have lopped off one bank of cylinders to make a inline four, it works. Unfortunatley cross-plane crankshafts have a lot of drawbacks including difficult to control vibration, unbalanced piston movement, poorer exhaust scavanging in certain exhaust configuartions and need for counterweights that add rotational inertia. Yes every American V8 you drove had a dirty kludge under the hood.
Inline 4's invariably have flat-plane cranks, so you've got that backwards too. Crossplane crank v8's have secondary balance, which actually means they're better balanced than flatplanes - Maybe you heard that flatplane's rev higher so thought this may be the reason they're better balanced? Not so, the reason for this is because of the lack of need for the large counterweights a crossplane has.
IMHO, a real V8 has a flat plane crankshaft. Truly the correct format for a V8, better firing order, more power, more balance and even better sound
Better is subjective, but the burble people love from v8 engines is only present in crossplane cranks. You can have this one though, because of v8 Ferrari's (although we all know the real Fezza engine is a v12).
