NGK numbers have changed some, but low numbers are hot, high cold. But they
also use letter modifiers. Such as:
COLD <<--B9HC B9H B9HS B8HC -->>Hot
The C plugs were always considered "racing" plugs. V means platinum such as
E is 3/4 reach, H is 1/2.
From: owner-fot@Autox.Team.Net [mailto:owner-fot@Autox.Team.Net] On Behalf
Sent: Tuesday, October 26, 2004 7:27 PM
Subject: Re: Interesting message
champions numbering system has hot plugs with the higher #,i.e.L87Y is a hot
plug used in a stock TR3. L82Y is a colder plug that works well with 10-1
compression. The old race plugs- L66Y was a hot plug; L61Y the cold plug
with L64Y in the middle.
I think NGk plugs use an opposite numbering system.
----- Original Message -----
From: "Jim" <email@example.com>
To: "Barr, Scott" <firstname.lastname@example.org>
Sent: Tuesday, October 26, 2004 9:48 AM
Subject: RE: Interesting message
> I haven't looked for any online explanations for plug ratings, but I
> can give a thumbnail answer.
> In proper operation, a spark plug is not supposed to ignite the
> fuel-air mix until it "sparks". In an ideal situation the flame is
> started at just the optimum time and progresses quickly.
> What can happen is that if it's a "hotter" plug than the application
> needs then the ceramic and the electrodes get hot enough to ignite the
> mix prematurely, acting like the glow plug in a diesel.
> How do you make a spark plug cooler (at time of manufacture, of
> course)?? The spark plug is cooled by heat transfer from the ceramic
> to the metal portion that threads into the cylinder head. So by
> changing the geometry of the plug ceramic the manufacturers can tweak
> how quickly the plug cools
> - in a relative sense- or how much heat they retain between firing cycles.
> If you could cross section a "hot" plug you'd see the ceramic is a
> long thin cone with the contact point to the metal far up the spark
> plug body. A "cooler" plug has more ceramic and contacts down closer
> to the electrode end.
> In the car, if the plug is too hot you'll tend to get pre-ignition
> under extreme conditions (pinging/pinking) which will do all kinds of
> neat damage. If the plug is too cool it won't burn off the carbon
> buildup and eventually foul. A perfect plug is one that is cool
> enough to not ping under full load, but good enough to keep firing
> under cooler conditions.
> Dallas TX
> > <<the best race plug ever made.>>
> > OK, I'll bite -- so what makes a plug a good "race plug"? The spark
> > (like a large, but decreasing, number of parts of our cars) have
> > always been a mystery to me. What makes one hotter and one cooler?
> > What do
> > see on the end of the plug that tells you whether you need hotter or
> > cooler? Are there any recommended reading resources out there?
> > Scott (B.)
> > -----Original Message-----
> > From: owner-fot@Autox.Team.Net [mailto:owner-fot@Autox.Team.Net]On
> > Behalf Of Ted Schumacher
> > Sent: Tuesday, October 26, 2004 7:16 AM
> > To: Herald948@aol.com
> > Cc: fot@Autox.Team.Net
> > Subject: Re: Interesting message
> > Andy, we still have Champion gold paladium plugs in stock. Probably
> > the best race plug ever made. Plug numbers end in "G" to denote the
> > gold paladium. A real race only plug. Ted
> > Herald948@aol.com wrote: