William M. Gilroy had this to say:
>I must be missing something. If you have four cylinders and each cylinder
>has its compression stroke at a different time, I would think the that
>engine would stop at one in 4 places on the flywheel that are 90 degrees
>apart. Why would this be wrong?
>
>Bill Gilroy
>77 Midget
>90 Shar-Pei
>
Because there are actually only two crank positions, not four, if you can
see what I mean. Two pistons are at TDC at the same time -- one on the
compression stroke and one on the exhaust stroke. The other two are both
at the bottom at this time. So, as Barney said, the engine could stop at
either of two places, 180 degrees out, depending on which *pair* of
cylinders was at the top of the stroke -- one of the pair being on
compression and one being on exhaust, but it doesn't matter (to the crank
position) which one is which. And, to be precise, the crank doesn't
really stop at TDC, necessarily, just at two symmetrical positions of
least resistance.
Since the flywheel has 6 bolts, you can rotate it 60, 120, or 180
degrees. The first two are essentially the same thing for this purpose.
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.
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