[Mg-mmm] MG PA spark plugs

[Hiro Nishio]

Hi Pete, 

You are correct. I just short cut the explanation.
There is Japanese explanation here at the web, maybe somewhere in English?
http://www.ngk-sparkplugs.jp/products/sparkplugs/basic/03_01.html

I have a very good friend working for NGK and one day he gave me a good
instruction.
"Never use wire brush to remove soot. Better way is to use torch to burn
soot,
or to use sand blast to clean"

After that I always carry several sets of spare plugs, soot cleaned by
acetylene torch,
but no wire brush in my tool roll!!

Hope it helps. 

Cheers,
Hiro

-----Original Message-----
From: Pete Thelander [mailto:pthelander at earthlink.net] 
Sent: Wednesday, October 28, 2009 3:06 PM
To: Hiro Nishio; TATERRY at aol.com; lawrie at britcars.com; mg-mmm at autox.team.net
Subject: RE: [Mg-mmm] MG PA spark plugs

Hiro,

You have the NGK designations almost correct.  My NGK catalog gives the
following breakdown of the letters.  In the plugs under discussion - BP6HS :

the first letter designates thread diameter.  B = 14mm
Second letter indicates the type of construction.  One or more may be
combined.  P indicates a projected insulator type.
    A standard plug construction would have no second letter. 
Next comes the heat range from 2 for hot to 12 for cold.  
H indicates  the shorter 1/2" thread length - E would indicate the 3/4"
longer thread length. 
S indicates a standard 2.5mm diameter center electrode

I hope this will get everyone straightened out and on the same page when
talking NGK plugs.  There are many more choices in each category, but they
are not applicable to our MMM engines.

Pete 
pthelander at earthlink.net



> [Original Message]
> From: Hiro Nishio <hiro at octagongarage.com>
> To: <pthelander at earthlink.net>; <TATERRY at aol.com>; <lawrie at britcars.com>;
<mg-mmm at autox.team.net>
> Date: 10/28/2009 3:14:55 PM
> Subject: RE: [Mg-mmm] MG PA spark plugs
>
> Lawrie, Terry, Pete, and all,
>
> First of all, there are usually two reach lengths available, longer one is
> 3/4"(19mm) and shorter 
> one is 1/2"(12.7mm). In case of NGK, "BP" means longer one, and "B" means
> shorter one.
> 3/8" (9.5mm) is hardly used in my case.
> And there are two kind of tips, extended one (ES) and normal (HS).
> Hence BP6ES has 3/4"(19mm) reach and extended nose. B6HS has 1/2"(12.7mm)
> reach and normal tip. 
>
> Theoretically I think the long reach + extended nose plug would ignite
well
> inside the combustion chamber, 
> but after trying many kinds of plugs including iridium to M/J/P/F/K/L/Ns,
> the actual result was vary, 
> some car was good with BP6ES, but some was good with B6HS.
>
> Recently I rebuilt an F Magna engine (it had 14mm thread instead of
original
> 18mm - someone in the past 
> modified) and I thought BP+ES should be good by exactly the same thought
as
> Lawrie.
> Then fitted BP6ES first, not satisfied. Then changed to BP6HS, which I
> usually use for any normal MMMs, 
> better but not perfect, then finally B6HS, very good. No misfire occurred
at
> all finally.
>
> Lawrie, spark plugs are cheap, so try many and find the best one - it is
one
> of the fun given to us 
> to play with old MGs.
>
> But do not use iridium plugs! That's expensive but no good for MMMs,
unless
> rather lean mixture setting.
>
> Good luck,
> Hiro
>
> -----Original Message-----
> From: mg-mmm-bounces at autox.team.net [mailto:mg-mmm-bounces at autox.team.net]
> On Behalf Of Pete Thelander
> Sent: Wednesday, October 28, 2009 9:11 AM
> To: TATERRY at aol.com; lawrie at britcars.com; mg-mmm at autox.team.net
> Subject: Re: [Mg-mmm] MG PA spark plugs
>
> Lawrie, Terry et al,
>
> I have been using the NGK BP6HS for the past ten years in the NE.  The
1/2"
> reach plugs are a bit short, but that is why I run the extended tips.  So
> far as Terry using 5s and my using 6 or 7s,  The compression ratio is up
to
> the original spec at 9.8:1.  I don't think Terry is near that high, so the
> 5s might be more appropriate for his car.
>
> Pete 
> pthelander at earthlink.net
>
>
>
> > [Original Message]
> > From: <TATERRY at aol.com>
> > To: <lawrie at britcars.com>; <mg-mmm at autox.team.net>
> > Date: 10/27/2009 4:23:00 PM
> > Subject: Re: [Mg-mmm] MG PA spark plugs
> >
> > Lawrie, I am using NGK BP5HS plugs in the NA....seem to work well but
not 
> > so much time or mileage yet....these are 1/2" reach with an extended 
> > nose....recommended by Bob Bazzica for use in all my cars, TA, TF,
Arnolt
> and NA.....
> > What are others using?
> > Terry
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