In a message dated 97-10-02 22:10:38 EDT, suhring@lancnews.infi.net writes:
> The ground wire attaches to the
> engine block. Would the GM conversion also require a ground wire? I
> assume
> if so, I'd just attach to the same location as is on the Lucas model.
>
> I also read your personal experience and am concerned as to the work
> required
> to get the alternator properly mounted. Also, in changing the belt, did
> this
> have any impact on the water pump (i.e. the width of the belt used for
> the GM
> vs what is now used on my Lucas)?
Scott:
The GM alternator is grounded through the case, so no external ground is
required. However, when you get the alternator, there will be a large screw
in the back of the case for a ground connection, if you should choose to use
one. The other end should be attached to the block, the same as on the Lucas.
On my own conversion, I just removed the screw, as the original Lucas relied
on the case for ground.
The mechanical details of the conversion are really a lot simpler than they
sound. When you actually have the alternator in your hands, the "boss" I
spoke of will be obvious. I placed mine in a "woodworking" vise (if you don't
have one, I highly reccomend getting one, even if you don't plan on doing any
woodworking. The jaws open up about 12 inches, and have soft wood inserts.
The "crushability" of the soft wood makes them super for holding odd shaped
automotive components without damage, and the large size holds most anything
you would want to work on), and used a hacksaw to cut the boss off. Before I
sawed it off, though, I covered the alternator with paper and masking tape to
ensure no filings got into the case. After the hacksaw, I used a file to
smooth the cut, and to get the surface perfectly flat.
I bought a chrome alternator support from the parts store (about $15), and
cut about 4" off of the engine end, and bolted it to the same bolt that held
the original bracket. When you are marking the place to cut, be sure to swing
the alternator through the entire range of the adjustment slot to get the
maximum movement so the belt can be changed easily. After cutting, I drilled
a new hole for the bolt.
The alternator support on the side of the block comes off with two screws,
which are threaded into blind holes, so there is no coolant or oil leakage.
The metal is fairly soft, so the 3/8" drill went through very easily. It's
best to use a drill press if you have one, but with a little care, it's not
necessary.
The front engine cover plate needs to be ground off flush with the alternator
support, but only on the top and a little bit to the left of the support.
There is plenty of material to work with, so there is no danger of cutting
into something you shouldn't. Here again, when you actually have the
alternator, and hold it in place, it will be very obvious what needs to be
done. Unfortunately, I can't think of a real good way to describe it without
pictures. (I think I will take it off sometime next week and take pictures to
put on the VTR page).
I bought a 44" X 3/8" fan belt, and it fit perfectly, both on the new
alternator, and on the existing fan and water pump pulleys. (the belt that I
bought was part no. 44013, which I think is supposed to be 13/32" wide, but
it is actually 3/8"). If the first alternator the parts man brings you
doesn't have the right size pulley, send him back to get another till he gets
one that is right. Most of them come with the correct size for your
application. No problem if the belt rides a little low in the alternator
pulley - that just makes the alternator spin a little faster, which is a help
at idle, where you need the help the most!
If you prefer, you could fabricate a bracket, to bolt to the original
bracket, and not have to modify either the alternator or the engine mounting
details, but it would be a lot of extra work. I think it took me about an
hour, maybe two, to complete the swap, including the time spent
"engineering," but excluding the trip to the store to get the belt and the
bracket, and I am NOT a fast worker!
Good luck, whichever way you choose to go.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition
'68 MGBGT---organ donor for the '74
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