Cam timing question

[huevergo]

This is more of a general question but thought i could find the answer here.
I am really into cars and all. I saw this animation of a Chevrolet V 8 engine in motion and how much i saw, each cam rotation, it fired only two cylinders on each bank. If all cylinders were fired together (all 8 in this case) ,shouldn't we get more torque?
I know we will have the same RPM, but there should be increased torque. And not a single engine i know, has all cylinders fired at once. Why?

[Lycoming]

You'll get more peak torque, but then you don't get any more torque for quite some time. The amount of work done per cycle does not change, therefore power does not change.

Also, you run into all the problems that single cylinder engines have with higher stresses and more vibration.

[Tommy Cookers]

one cam rotation (in a 4 stroke engine) takes 2 engine revolutions
an 8 cylinder 4 stroke engine fires 8 cylinders individually (ie at 8 intervals of 90 deg) in 2 engine revolutions
yes with cam mods it could fire cylinders in pairs (ie 4 intervals of 180 deg)
this would increase the crankshaft stresses (in road driving anyway) and need a more downshifting to avoid surging or even stalling
with no benefit - in driveability terms you would have converted your V8 into an inline 4
similarly an inline 4 could have paired firing and have driveability like an inline twin
the vibration associated with engine rotation would be no worse, but the driveability would be worse

but a 90 deg V with 2 (eg Ducati), 4, 6 or 8 cylinders etc has only secondary frequency vibration if the crank is counterweighted
so a 'single throw' crank90 deg V8 could simultaneously fire all 4 cylinders in 1 bank, with only secondary vibration
like eg 4 Ducatis fixed together, so having firing intervals of 270 deg and 450 deg (or otherwise 90 deg and 630 deg !)
a 'two throw' crank 90 deg V8 could fire all 8 simultaneously but have also primary frequency vibration (and 720 deg firing interval)

Puch and TWN ? production 2 stroke twin motorcycles fired all cylinders simultaneously ('split singles') allowing better porting
and briefly in others eg Yankee Ossa , and even in one or two 4 stroke twins eg a Johnny Giles Triumph

firing in pairs was used in 2 stroke square 4s eg Suzuki RG 500
and in eg 2 stroke diesels with lots of cylinders eg Napier Deltic

[J.A.W.]

Here is an engine firing order graphic.. http://www.enginehistory.org/fo/FO.shtml

Firing order harmonics are interesting..
.. both Napier & R-R built H-24 mills, ( effectively X2 180`-flat- V12s superimposed),
Napier phased each 12 cyl unit to fire 180` apart, & coupled their cranks via a sophisticated/balanced multi gear-drive,
- whereas R-R fired upper/lower banks paired simultaneously & used a simple spur gear to couple the dual crank output..
..the R-R method failed catastrophically..

[riff_raff]

Regarding the effect of combustion event frequency/intervals on the brake torque characteristics of a recip piston engine, in most cases it is not a major concern. There is usually enough polar inertia produced in the rotating assembly from a combustion event to keep the crank from stalling.

It can be a bit beneficial if the interval between combustion events is evenly spaced, or spaced such that it does not create a dynamic vibration coupling problem in the rotating components.