FWIW my 12v roadster coil has a secondary of 5.4k, my V8 6v coil 6.5k, and a
typical 12v 'sport' coil 8.3k.
PaulH.
----- Original Message -----
From: "Stephanie Lupynec" <renoman@sympatico.ca>
To: "Paul Hunt" <paul.hunt1@blueyonder.co.uk>; "mgs" <mgs@autox.team.net>
Sent: Tuesday, September 20, 2005 6:10 PM
Subject: Re: coils
> If somebody could measure the secondary resistance on an MGA HA12 coil it
> would be interesting to compare.
>
> Turns out the Lucas coil which I thought was an HA12 is actually a smaller
> diameter LP12. It along with an assortment of 5 spare generics reads under
4
> ohms primary and under 10K secondary. The LA12 I'm looking at using is 3.8
> ohms primary and 48K secondary.
>
> Thanks to Paul, I now know where the LA12 originally came from - a
friend's
> 1098 sprite - and since they are listed interchangeable for 1 liter
motors,
> it should be OK on the 1600.
>
> Mike
>
>
>
>
> ----- Original Message -----
> From: "Paul Hunt" <paul.hunt1@blueyonder.co.uk>
> To: "Mike L" <renoman@sympatico.ca>; "mgs" <mgs@autox.team.net>
> Sent: Tuesday, September 20, 2005 10:01 AM
> Subject: Re: coils
>
>
> > Whilst it will almost certainly work, and not do any damage as such, it
> > *will* have different characteristics. The much higher resistance of
the
> LA
> > 12 primary could mean it is much finer wire, which will tend to limit HT
> > current and spark energy. Or it could be due to a much larger number of
> > turns which will give a higher potential (ho ho) HT voltage and greater
> > spark energy. It seems to have been used on many Brit cars like the
1098
> > Sprite, Mini, Reliants (for which both are quoted as suitable), Lotus
> > Europa. But a Jag XK120/140 site says not to use the shorter LA12 in
> place
> > of the HA12. This *may* be because with the shorter dwell time of the
Jag
> > the LA12 loses spark energy at higher revs, but I'm only guessing.
> > Shouldn't be a problem on the MGB though. A Moggie 1000 site says the
> HA12
> > is a higher powered coil than the LA12. Do they both have the same
> primary
> > reading i.e. about 3 ohms?
> >
> > PaulH.
> >
> > ----- Original Message -----
> > > MGA coil is supposed to be a Lucas HA 12 and I have a spare LA 12
> > available.
> > > Difference seems to be the hi tension ohm reading is 48K on the LA 12
> > versus
> > > 8K ohms on the HA 12.
> > >
> > > Are they interchangeable?
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