Cylinder numbers are cast (marked) on the block. Cylinder 1 is near side front, cylinder 2 is offside front, cylinder 3 is near side rear, and cylinder 4 is offside rear. The firing sequence is 1-3-2-4. This has been discussed many times in the past because the firing order of a true boxer engine like the Gamma is Left, Left, Right, Right.
Have a look at my very old forum posting from 2006 (in the old, old forum!
) at
http://lanciagammaconsortium.info/gamma/_forum/0000019e.htm"I too was confused about this but your Gamma manual is correct for the firing order and so are the cylinder markings on the block. The balance of the engine is dependant on the position of the pistons and not the firing of the spark plugs. The boxer engine is also commonly known as a “horizontally opposed engine” because the opposite pistons reach top dead centre simultaneously, thus balancing each other with respect to momentum. So when number 1 piston is travelling into the cylinder, the opposite piston in cylinder 2 is also travelling into the cylinder. So 1 is in power stroke so 2 must be in intake stroke and pistons 3 and 4 are travelling outwards is compression and exhaust strokes. So the next cylinder to fire is number 3 having just done its compression stroke at which time the opposing cylinder number 4 is in the intake stroke while 2 is in compression stroke and 1 is in exhaust stroke. Then number 2 fires while 1 is in intake stroke, 4 is in compression and 3 is in exhaust. Then 4 fires, 3 is intake, 2 is exhaust and 1 is compression. "You can see the very very old original forum at
http://lanciagammaconsortium.info/gamma/index.htm.
The articles are still there containing a lot of information but the "Next" and "Previous" buttons don't work so you need to use your back button to return to the home page before going onto the next post or reply. Maybe I should try transferring all that information to the current forum....
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