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Old 10-05-2007, 09:14 AM
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it takes two revolutions

As I said before, it takes two full revolutions of the crankshaft to go through the firing order. There is an obvious difference between the compression stroke and exhaust stroke - even though both go to TDC position on every rotation. If you start with number one on compression - the second cylinder in the firing order will come up in 90 and so on - there will be a second piston at TDC in every case - but adjusting the closed intake valve on it risks being off the base circle. Every 90 the cam closes both valves on a cylinder - that's the one you want.

The micrometer effect of the rocker nut -
A 3/8-24 UNF nut moves the pivot down .042 per turn 6 flats = .007 per flat. For a 1.5:1 rocker this means that three flats (180) will compress the lifter plunger 3 x .007 x 2.5 1.5 = .035". If you turn it 6 flats (360) its doubled to .070".

For a 1.6:1 rocker - the math is 3 x .007 x 2.6 1.6 = .034" (in 180)
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