401 Ignition Coil

[dezelsky]

I recently had the misfortune of a failed ignition coil in my 401
(whilst travelling on the M25, of course). After the car was
recovered, as it was a Sunday I was unable to get a direct replacement
(Lucas B12 or suitable replica), but I did manage to scrounge a Lucas
Sports Coil as fitted to an Aceca Bristol, which seems to work
perfectly well. I have tried to verify the compatibility of the sports
coil as a replacement to the standard, but have been unable to find a
definitive answer. There are comments on other make sites suggesting
that the Lucas sports coil should not be used as a replacement to the
standard item. Does anyone on the forum have any thoughts on this? Is
the sports-coil likely to damage other parts of the ignition system or
is it actually a better alternative to the B12?

Paul

[brianjgkidd]

> > I fitted a high energy coil to my 405 a few years ago, with beneficial results - never any problem with misfiring. However, this type of coil may need to have a ballast resistor fitted, which reduces voltage to the coil of about 7 volts, lessening wear of contact points, etc.. But this may require the fitting of a modified starter solenoid to allow the ballast resistor to be by-passed to ensure full battery voltage to the coil during starter motor operation. This momentary voltage overload is acceptable, but continued operation without the protection of the ballast resistor is likely to lead to damage to the coil.

Regards,

Brian Kidd> > > > >

[Ashley James]

I thought I'd posted this but I'd caution against using sports coils
on old ignition systems with dynamo charging circuits. First they
take an amp or two more from an overworked dynamo and this might be
make or break on a cold night home in dark and rain, and the rise
time is much faster and this often causes arcing elsewhere than the
plug.

Mart, my business partner is an electronics engineer and he tells me
standard one is okay to 12-15000 rpm on a Bristol, so hopefully enough
for yours.

www.vintagemotorspares.co.uk for a cheap Lucas original.

Ash

[brianjgkidd]

> > Well, my 405 is fitted with an alternator. But there is no question in my mind of the benefits of the high energy coil - at least in my experience, including some quite arduous continental tours to Italy, where the ignition system performed perfectly, and never with a hint of a misfire.

Regards,

Brian Kidd> > > > >

[Richard]

Originally Posted by brianjgkidd

> > Well, my 405 is fitted with an alternator.

I would be interested to know which alternator you have fitted and what other modifications it required.
I have been considering replacing the dynamo on my 405 with an alternator but have postponed it for the present as not being worth the effort.
Richard