At 04:24 PM 12/28/98 -0800, David Ambrose wrote:
>Mark Rayborn wrote:
>
>> How do I tell if my engine has been bored before? ....
>> pistons 1 and 3 are different from 2 and 4. ....
>> .... Seems like I read where the pistons should be stamped with
>> the oversize number. ....
>>
> If the engine has been bored, the machinist should have stamped some
>number in several places on the top end of the block. ....
Not necessarily. I've had several engines rebored, in at least three
different shops, and they have never made any marking on the block.
Oversize pistons usually (but not always) have the size stamped on the top,
something like ".030 O/S", or maybe just ".030".
>> The big end of the #1 rod shows quite a bit of wear (grooved about 1/32
>> inch deep) on the side of it. .... These
>> are the kind that use no nuts. My Vikki Brit catalog shows them as being
>> used only on earlier engines until '67. My engine number places it as
>> manufactured in '70. Which rods should I use?
Connecting rods using cap screws were used on different engines. The three
main bearing engines, 18G & 18GA (1963-1964) used rods with two different
part numbers, having left and right handed offsets at the big end. The
five main bearing engines GB through GF (1965-1968) used four identical
rods with no offset at the big end. After that the MGB engines used
through bolts and nuts on the big ends of the rods.
Now if you have a rod from a 3-main engine installed in a 5-main engine,
there would be a definite misalignment at the big end which would (if it
could ever be assembled) cause immediate and excessive wear on the bearing
and heavy scuffing on one side of the big end. The offset is easy to see
looking at the rod edge on. Any rod for a 5-main engine should have no
offset at the big end.
>> .... local NAPA has a machine shop. ....
>> .... they said they would be happy to do the machine work
>> although they are not too familiar with the B engine.
If you trust your local machine shop, one iron block is pretty much like
another iron block. If it's flat on top and has vertical bores, it's all
the same to them, no problem. They have books with the spec's for most
common engines.
>> They said that
>> they would be unable to do the cam bearings if they were the
>> "semi-finished type". They said they did not have the means to bore the
>> bearings in place. ....
>
> Try to find another machine shop. As I recall, the cam bearings need
>to be bored out once they are installed. ....
If the block gets hot tanked for cleaning, the cam bearings will have to be
replaced. Let the machine shop procure the cam bearings for you. They
will get the precision type that do not need machining after installation
(if properly installed). However, do give them the cam so they may check
its fit in the bearings before delivery. (That's just a very nice way of
telling them to "be careful about the fit" without sounding like you're
telling them how to do their job). No excuses that way, and no boo-boo.
Barney Gaylord
1958 MGA with an attitude
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