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Bosch vs NGK plugs

To: datsun-roadsters@autox.team.net
Subject: Bosch vs NGK plugs
From: Teddy Seidenfeld <teddy@stat.cmu.edu>
Date: Wed, 13 Oct 1999 09:41:39 -0400
Dear Friends,

For several hundred miles, I ran Bosch W8D plugs in my stock 69 2000.  As a
matter of personal opinion, I was rather surprised to find a loss of power
compared with how the car feels using the recommended NGK B6ES plugs.
According to the temp. gauge, there wasn't much difference; however -- and
here the short mileage with the Bosch plugs is not enough to make an
accurate estimate -- I think that the Bosch gave me inferior performance
with a drop of about 5 -10% in mpg.  (Detail: I had them all set with a
.029" gap.)

The obvious (visual) difference between the plugs is the position of the
gap, relative to the shoulder where the plug meets the cylinder head.  The
NGK's have the center of the gap at approx. 19mm out from the shoulder,
whereas it is approx. 22mm out on the Bosch.  (Aside: Champion N9YC have
their gap center at approx. 21mm out.)  Of course, that difference starts
the controlled explosion at a different place within the cylinder.

Is that the principal difference explaining how the two perform inside a
U20, or are there other factors that contribute significantly to the
general preference for NGK over Bosch?  And where do you put the Champions
in this race?

Curious,
Teddy
SRL311 08018
Pgh PA
OROC



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