At 08:53 AM 5/27/98 -0500, Bill Eastman wrote:
>.....
>The ring gear is worn in a couple of spots only (typical of four cylinder
engines). I know this is crazy, but can anyone think of a down side to just
re-indexing the flywheel to put fresh teeth where the wear has occurred.
I have done this, and it works fairly well. Afterwards the starter pinion
would only stick about 1 time in 100, where it used to stick about 1 time
in 10 before re-indexing. Unfortunately it was not a perfect cure, so
eventually I replaced the ring gear.
>I am thinking about having the flywheel lightened. Anyone have any
recommendations about area and amount to cut? I would have this done if I
choose to have a new ring gear professionally installed.
Given the proper dimensions (which I have and could supply), you can
machine material from an MGA flywheel to lighten it a bit to the same
profile as the flywheel from a 3-main MGB. As a matter of economics, you
can likely buy a used 3-main MGB flywheel for less than the cost of
machining the MGA flywheel. If you want even less weight in the flywheel,
you had best consult an expert in such matters, because the removel of
material also reduces the strength of the piece. For serious competition
work, you might consider buying an aluminum flywheel.
>Has anyone installed a starter ring gear at home? Any pointers that you
are willing to share?
Having done this once, it turned out to be reasonably simple and easy. And
this is another one of those "I did it myself" ego trips, because it sounds
a lot more difficult than it really is. To remove the ring gear, you cut
about half way through gear between teeth with a hack saw, then use a cold
chissel and hammer to break the gear at the cut, and it comes right off.
Putting the new one on takes a bit longer, but it's also more fun. It's
party time!
Throw a back yard barbeque and invite a few friends. In this case you need
to have a charcoal grill, because a gas grill has a hard time getting the
temperature high enough in an expedient manner. After the food is done,
and the coals are all nice and white all over, just drop the ring gear
right on top of the coals and cover the grill for about 15 to 20 minutes.
Ideally you want it to turn blue, then remove it from the heat before it
loses its hardness. However, it's not that big a deal if you overheat it
and it starts to glow a little red.
Be sure you put it on the right way around, chamfered gear tooth ends to
the rear (away from the shoulder on the flyweel). Just drop it onto the
flywheel and squirt some oil on it with a hand pump oil can to cool it at
the right rate to get the hardness back. If you were to water quench it,
it could get brittle and crack. If you allow it to air cool (slowly), it
could end up fully tempered (soft), leading to accellerated wear. As it
cools it shrinks to a permanent tight fit. Have a drink and congratulate
yourself as it finishes cooling.
Barney Gaylord
1958 MGA with an attitude
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