>>Larry writes:
>>
>>... 'A's were fitted with a mechanical tach that is driven by a
>>gear on the cam ... the 'B' engine did not have this drive gear so
>>... you guessed it ... the DPO utilized a 'B' tach ... IOW,
installation
>>of the 'stock' tach would require replacement of the cam.
>>
>Oh, contraire! The so-called MkI B's did have a mechanical tach. My
'63
>with its 18G engine certainly does--in fact, I'm d**n proud of the fact
that
>only my gas gauge is electric (least reliable, too). I'm not sure when
the
>B switched to an electic tach, but I'd guess with either the 18GA or
18GB
>engine. So, it sounds more and more like the "18G" engine in the '59A
is a
>mid-production MGB engine, that also has a late head on it. Did the
"18G"
>engines have smog pumps?
>
... boy you early 'B' owners are a testy bunch <g> ... last eve Bruce
Durgin
(proud owner of a '64 B) wrote:
>I believe very early MGB's had a mechanical tach and
>that it was changed to electrical tach around early 64
>model.
>
... and I replied:
>... right you are ... the changed conincided with the
>introduction of the 5 main bearing engine ... the 3 main
>bearing engine utilizies the the tach drive gear (on the
>cam) and the tach pinion housing (bolted to the block)
>from the 'A' ... in fact there are lot of other things that are
>common between the 16GC engine (1622cc - MGA 1600
>MkII) and the 18G/18GA engines.
>
>I *ass*u*me that the engine in question is a 5 main bearing
>given that "there are pipe plugs in place above the exhaust
>ports for the air injection equipment" and that the elec tach
>was installed ... besides, I never stated that I was an 'expert'
>nor that all 'B's had electronic tachs <bg>.
Will to my knowledge 'smog pumps' were not introduced until
after the introduction of the 5 main bearing engine ... of
course the DPO (just to spin Dave up again <g>) could have
installed a later model head on a 3 main bearing engine ... and
he could have installed an electronic tach when the mechanical
drive was available ... but I guess we won't know until we see a
complete engine number.
Larry "I ain't no stinkin' expert" Unger
larry.g.unger@lmco.com
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