The coil on a 78 would be a 6v item whereas that on a 73 would be a 12v, the
difference being accounted for by the loom ballast resistance in the later
car. I realise that both these items are part of the rest of the car and
not the engine, but you should keep the later distributor with the later
engine for its advance characteristics, and if you keep one of the factory
electronic ignition systems with the engine you need to keep the coil and
hence will have to provide a ballast resistance and the additional power
supplies that each uses. The later engine may also suffer from difficult
cold starting if it does not retain the later starter and solenoid that
gives the 'boost' effect together with the 6v coil. If yours is a true 73
model then it should use the same white/black signal wire back to the tach,
but if it is a late 72 model with the loop-type tach this may not work
correctly with the later electronic ignition systems. If you keep the
electrically heated manifold then this may need a connection back to the
green (fused ignition) circuit or you may get poor running during warm-up.
What about the cooling fan? The 78 has electric and 73 mechanical. If you
don't fit a mechanical fan to the later engine you will have to provide a
relay and fuse to power the electric fan off the brown circuit, it takes too
much power (not a fusing problem but simply one of too much current through
the ignition switch) to run it off the green.
----- Original Message -----
From: "Clancy" <clancy@idir.net>
To: "MG Group" <mgs@autox.team.net>
Sent: Saturday, April 05, 2003 10:35 PM
Subject: engine transplant
> If I put an engine out of a 78 B into my 73 B what do I have to change
out. I
> intend to use my exhaust manifold, intake and carbs, thermostat housing,
the
> 73 style hoses and radiator. What else is different?
/// or try http://www.team.net/cgi-bin/majorcool
/// Archives at http://www.team.net/archive
|