Zach:
What a can of worms...
Thanks to Paul Tegler there is a reference for the 41234 Distributor at
http://www.teglerizer.com/mgstuff/advance_curves.htm
Paul shows that distributor as needing a ported vacuum source, not the
manifold only vacuum source available on your manifold/carb combination.
So, you are going to have difficulties getting the engine into correct tune
even with a brand new vacuum unit. This makes sense as the unit was
probably fitted to UK spec cars which continued to have a ported vacuum tap
since efficiency was important, rather than emmissions.
If this information is correct, there is no problem running the engine with
the vacuum unit disconnected. You will have to advance the timing at idle
from the settings used with the Federal spec distributor to those used on
the earlier and UK car. About 14 degrees BTDC at idle should be a good
starting point. The only draw back is going to be lowered part throttle
efficiency, which is what the ported type vacuum advance unit is there for.
I'm still trying to figure out a suitable replacement distributor for the
later US manifold tapped carb setups. Unfortunately this area of
engineering appears to be in the realm of large monsters and dragons.
Kelvin.
>
>
> I have contacted the list before regarding my replacement
> distributor, but am now at another loss. I have a '73 B that
> I replaced the distributor with a '72 18V HC piece. I think
> that I have the problem narrowed down to the vacuum unit.
> When the vacuum advance is unplugged but the port of the
> manifold is plugged the car idles fairly well, but when I
> hook the advance tube back up the car starts to shake and
> fluctuates about 200rpm. I did a quick check last week that
> consisted of disconnecting the hose from the manifold and
> since I didn't have the mityvac handy, I just blew into the
> hose and there was a noticeable hiss coming from the
> distributor. I assume that this means the vacuum unit needs
> replaced. Now the problem, the distributor number is 41234
> H, Moss does not have anything that corresponds to this
> number. Their book just lists 41370 for the '72 models.
> Will this work or am I trying to do something that won't
> work? Also, would I hurt the car if in the interim!
> I just disconnect the vacuum hose and plug the port and
> drive the car that way?
>
> Thanks,
>
> Zach
> New DSL Internet Access from SBC & Yahoo!
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