Engine Configurations - Why?

[Foxy3.0]

a true boxer shares some properties of an inline 6, the way the cranks are set out (seperate pins for each conrod) means that opposing pairs are in the same position on their stroke at any given time.

a 180 degree V engine does not do this, the crank pins are shared by opposing pistons meaning that it has the same disadvantages as a narrower angle V engine in terms of engine balance.

Torque is not really a by product of engine configuration but a product of stroke length, a longer stroke engine will produce more torque than a short stroke engine, as power is torque X revolutions that is why (on a basic level) small capacity engines, or those with a short stroke and larger bore, tend to rev much higher than their long stroke counterparts in order to make the power. This gives a very different driving characteristic, so manufacturers won't always put the same engines in all their range for a number of reasons including physical size, transmission, and the expected driving characteristic of the vehicle in question.

 

[sars]

Torque is not really a by product of engine configuration but a product of stroke length, a longer stroke engine will produce more torque than a short stroke engine, as power is torque X revolutions that is why (on a basic level) small capacity engines, or those with a short stroke and larger bore, tend to rev much higher than their long stroke counterparts in order to make the power.

Partly true, it's also a function of how many cylinders you have and thus how many you can have doing work at the same time. V engines share crank pins where as the boxer or inline have separate pins for each cylinder and thus have different timings and will thus have a different torque characteristic. A 4 cylinder will only have one piston working at anytime whilst a 6 cylinder will have two, in a boxer they will be working together at the same time, in an inline they will be slightly staggered and a V they are opposed.

Small engines tend to rev higher, not because they can, but because of the cost/benefit relationship, perfectly illustrated by the Ferrari V8 in the 358.

 

[shotbybothsides]

I don't know much about engine design except that there have been so many variations on design including firing order, crank phasing, number of conrods per crank pin etc etc that whatever anybody cites as the definative configuration, another will come up with an example of a different arrangement.
Balance shafts, firing orders, rpm and component masses also have a big part to play in perceived smoothness, as does the method of mounting the engine in the vehicle.
Geat to see the deltic earlier in the thread, what a fantastic peice of lateral thinking, shame it got canned as a railway power unit. They sound amazing as well.

 

[Wildfire]

Lets forget about the wankels

The main difference is v8s barble and can snap knicker elastic at 10 paces, v6 growl, straight 6s yowl and 4 cylinders don't ...


That's all we need to know

S6 is balanced and smooth. V6 fits in compact spaces. V8's are generally awesome (especially cross plane V8s). IL4 sounds best in a bike @ 15000rpm.