Haynes says 25 for the 25D4 and 35 for the 45D4 and 45DE4. 40 is not
unreasonable for a sport coil. Never heard of 'large gap' plugs, the
single-electrode Champion and NGK I use are adjustable for any gap I have
ever heard of.
PaulH.
----- Original Message -----
From: Eric <eric@erickson.on.net>
To: <mgs@autox.team.net>
Sent: Sunday, May 28, 2000 9:19 PM
Subject: Sports Coil Plug Gap
> Reading back through the archives (as I do before changing ANYTHING on
> my car), I was looking for some comment on the increased gap recommended
> when you install a Lucas Sports Coil. Everyone says 'increase the gap'
> but I was seeking something more definitive and found the following from
> wayyyyyy back. Any comments anyone?
>
> Way back in history, MGBob said:
> >
> > Date: 08-Jul-1997 08:24:06
> > Subject: Re: Reading Spark Plugs
> >
> > Addressing the Sports Coil idea, at the GOF Newton sports coils
> > were mentioned. In the discussion, it was stated that a rule-of-
> > thumb for spark plug gap is .001" per M volts. Since the standard
> > Lucas coil delivers about 22-25M volts, depending on incoming
> > voltage, the spark plugs should be gapped at .025. The Lucas
> > sports coil delivers about 40M volts, so the plugs should be gapped
> > at .040 to utilise the extra power. This was new to me, but it was
> > then explained that Champion and NGK make plugs called "large gap"
> > or something similar, that are especially configured for the extra
> > gap and extra voltage. One might wish to check clearance between
> > plug and piston if compression has been increased.
> > Bob
|