Quote:
Originally Posted by PascaLM
Well, at least you can choose 1-3-4-2 or 1-2-4-3 sequence on the same engine configuration. You can modify the ignition advance timing (if correct expression in English).
They can change small details to avoid a complete re-architecture of the engine which should have taken too much time, no ?
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well lets consider a linear... still used like this (privileges torque)... 1 4 (firing) 2 3 (exhaust) - 1 4 ( exhaust ) 2 3(admission) - 14 ( admission) 2 3 ( compression ) - 1 4 (compressing) 2 3 ( firing) ... from 2 to 2 revs there are 2 revs without firings-> tends to rev low, not good for power ( play reverting order 2 up 2 down on the *same stroke* and see it leads to the same 2 by 2 order).
Since a piston goes up to compress or exhaust you can revert half of cylinders from firring or exhaust to the contrary( no more 2 cylinders on the same stroke but reverted) ...
*this without having to change the crankshaft*...
but then you'll have to change the top valve "camshafts", then you'll have something like 1234 (what ever, that is what some Tunning kits do that include new camshafts)
but there is never this change the firing order without changing nothing else (else is as if you start counting from the cylinder 2 firing instead of 1 but the sequence is the same)
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[ right balancing changing the crankshaft, usually is 1234 (whatever) but the spacing can vary a lot, can be even spaced or 2 by 2 pistons can be closer ]