Thank you for a very informative post. This one goes in the keepers folder.
Sounds like you already read the book and saved us the trouble with a very
nice condensed summary.
Glen
> Jackson my man!!
>
> The suggested plug (and heat range) is
> for "normal" driving which is pretty much
> defined as 50% highway, 50% town and
> assumes you are not driving around
> constantly at WOT and 6,000 rpm's.
>
> It is for the "average driver". It will stay
> "clean" by reaching and staying in the
> heat range wherein deposits are mostly
> burned off in the combustion process and
> in normal use will not get hot enough to
> approach un-necessarily the "ping" or
> "detonation monster" using the recommended octane gasoline in the
> STOCK motor.
>
> Now we enter into this "normal and average" equation, your basic
> spridget
> "lister", most of whom are less than
> average and very strange and weird,
> except for me (and maybe you, and I
> am not at all sure about you at this
> point!). <vbg>
>
> OK, let's get SERIOUS here. A lot of
> listers are "into" their cars and "tune"
> their motors for more power than stock.
>
> They upgrade to larger carbs, increase
> compression ratios, upgrade cams in terms of greater lift and longer
> duration, mount headers and free flow exhausts,
> etc., etc., etc.
>
> More "power", whether in the form of
> higher manifold pressures and/or greater
> rpm's produces more combustion heat.
>
> This normally calls for a cooler plug.
> which transfers combustion heat to the
> cooling system at a faster pace, thereby
> running "colder" in a "hotter" combustion
> process than "stock".
>
> Thus, most listers go from a BPR6 to a
> 7, as they find 8 to be too cold for even
> a well tuned street motor, though this
> heat range would probably be very satisfactory were their machines
> driven
> under race track circumstances, or
> supercharged street driven units.
>
> In practice, I have only found 8's to be
> suitable for my Judson supercharged
> applications in summer weather when
> induction temps are on the high side
> relative to ambient winter temps, cold
> air induction system notwithstanding.
>
> There are also various "tip" arrangements
> for the projected nose series normally
> recommended and used in Series A
> street motors. There are plantinum tips,
> iridium tips, splt center electrodes (BPEV
> series), "massive" electrode 4 prong
> types, etc. It's gotten to be a candy store
> sort of deal!! The projected nose series
> runs a broader heat range than most
> of the other types. This allows for a cooler
> plug whose who's "nose" remains clean
> of deposits as it is "projected" well into the heat of the combustion
> process.
>
> Go down to your local auto parts store
> and ask to see their NGK and/or Bosch
> catalog and really READ it to educate yourself in these matters.
>
> Bring your favorite drink along and find yourself a nook to sit in so
> you may relax
> and enjoy while you "learn"!! :)
>
>
>
>
> Cap'n. Bob
> '60 :{)
/// unsubscribe/change address requests to majordomo@autox.team.net or try
/// http://www.team.net/mailman/listinfo
/// Archives at http://www.team.net/archive/spridgets
|