Well, not 90 degrees (there are 6 bolts, not 4), but that was the general
idea. I guess that makes it 60 degrees, right? Anyway, you're right, the
gist of it was there's no need to unship the ring gear on a B, you just
rotate the flywheel position. Of course, this requires that you
remembered to mark its position when you removed it, and that resurfacing
didn't obliterate the mark. But perhaps there is a way to deduce the
position from first principles... (I think I recall there is a locating
pin -- that would do it).
And it isn't just a single location on the ring gear -- it's two opposite
locations. The simple technical reason is that the piston positions in
the MGB engine are "paired" -- if 2 are at TDC, the other 2 are at BC.
The crank stops rotating at shutoff at the position of greatest
resistance (from compression and presumably valvetrain resistance).
Whatever combination causes this will occur twice in a complete engine
cycle (you could argue that it would occur 4 times per cycle, but because
of the paired pistons, 2 of the four possible positions are the same as
the other 2). Which of the 2 positions it actually stops at on any given
occasion is random.
So as long as you don't rotate the flywheel 180 degrees, it should
improve the situation, starter-wise. Actual missing teeth on the flywheel
could affect its balance, I suppose, leading you to replace the ring gear
for smoother running.
Jerry Causey had this to say:
>
>I almost certain that we 4-cylinder folk can just turn the flywheel 90
>degrees (relative to the crankshaft flange) and bolt it up to "renew"
>the part of the ring gear that is engaged by the starter. The flywheel
>stops at the same location every time the engine is turned off for
>some simple technical reason that is way beyond my
>understanding. I think Barney told us so.
>
>Regards,
>Jerry
>
>> here's a little more insight on flywheels from another
>> uncollaborated source
>> *****************
>> I took the flywheel for the 1500 Midget to the machine shop today.
> <<Big Snip>>
>> After bead blasting the flywheel, the shop is going to turn the
>> flywheel ringaround to expose the unused side to the starter
>> gears . . .
>
--
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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