Your right Chris, should'a said a SHORTER path to the shell, hope our
friend reads this, I'd hate to have to buy a Chebbie! DK.
Chris R Harris wrote:
>
> Don,
> according to my info, a plug that has a shorter ceramic path to the
> shell is the cooler one, (ie) heat is conducted away qiucker due to the
> shorter path to the air or water cooled head.
>
> Chris Harris New Zealand.
>
> ----- Original Message -----
> From: "Don Kerr" <dkveuro@pop.flash.net>
> To: "Jim Dincau" <jdincau@qnet.com>
> Cc: <land-speed@autox.team.net>
> Sent: Sunday, July 30, 2000 11:36 AM
> Subject: Re: Spark Plugs
>
> > Jim. if the originals are doing a good job, then the next cooler for
> > high speed will be safe for sustained high loads. That is, a plug with a
> > longer ceramic path to the shell. However the only way is a dyno pull,
> > to compare HP output, as I have had an engine give up 38 hp at 7000rpm
> > with the wrong plugs. The mag will deliver a hotter spark if the
> > potential is built into the plug circuit and changes very little in the
> > final combustion temperature from the original ignition, unless, you are
> > using a hotter plug to prevent cold/oil fouling or to promote fire from
> > a bad combustion chamber design in the first place. Ignition initiation
> > is a process of the ironitation of a very small kernel of air around the
> > plug electrode, the change in ignition spark is not so much a better
> > spark but being able to cause a better spark by increasing the
> > resistance to ironitation at the plug by wider gap, higher compression
> > or a change in fuel/air ratio coupled with the swirl action of the
> > intake fuel mixture, or all or part of the above.
> > If a plug needs 12500 kv to fire it ,it will need 12500 kv
> > to fire with any ignition system type. The kernel starts the action by
> > ionizing the air much like a lightning strike does to the atmosphere,
> > just milliseconds before the main bolt strikes the faint upward leader
> > from an initiation point. The advantage of mags is that their spark gets
> > hotter up to a point as rpm's rise. Some while ago a CD ignition was the
> > way to go, now there are many different types to choose from, but mags
> > don't need the added wiring a conventional ignition does.
> > Power in an engine is a way it uses the air it breathes and
> > the combustion temperature should see no great change as it is a
> > chemical reaction regardless of the power it produces, just the amount
> > of calorific BTU's it now has to dump, which leads to a larger/better
> > radiator. etc etc etc etc.......
> > DK.
> > PS.....O'corse there will be some who don't agree, and will take issue
> > with what I've said here, but that's OK, I'm not the final authority on
> > ignitions.........YET! :-)
> >
> >
> >
> >
> >
> >
> >
> > Jim Dincau wrote:
> > >
> > > Magneto Don.
> > >
> > > ----- Original Message -----
> > > From: Don Kerr <dkveuro@pop.flash.net>
> > > To: Jim Dincau <jdincau@qnet.com>
> > > Sent: Friday, July 28, 2000 5:44 PM
> > > Subject: Re: Spark Plugs
> > >
> > > > Depends on the ignition system Jim.........DK.
> > > >
> > > > Jim Dincau wrote:
> > > > >
> > > > > Hi all:
> > > > > Here is a question for the group;
> > > > > Is there a difference in heat range required of the spark plugs in a
> > > > > normally aspirated alcohol engine versus a gasoline engine? This is
> > > > > assuming both are tuned up to the max re; cam compression and
> > > breathing.
> > > > > Jim in Palmdale who has nothing better to do.
> > > >
> >
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