My home inspection of Speedmaster heads
Are you planning on relieving the spark plug hole like some of us did
Bosch has's some pretty detailed info about their plug numbering system. The one I found has a standard length electrode, and a .875 reach (vs .750). It fits a 2.4l Nissan from the 80/90's, but it's discontinued (PN 7925). I used that to cross search and found a compatible plug. Standard reach, but with an extended electrode.
It's a standard 14mm, flat seat, .750 reach plug. But it has an electrode that is 7mm vs 4mm. That's an extra .118 of protrusion.
I haven't picked one up yet, but I have to go out today anyways, so I'm going to try and grab a test plug and I'll post pictures/results later.
Bosch Number - 6721 / FR8HPP30X
Champion - RC12MC-4
Neverlight - 5224
NISSAN 240SX 1989 - 1990 2.4L
NISSAN AXXESS 1990 24L
NISSAN D21 PICKUP 1990 - 1994 2.4L
NISSAN PICKUP 1995 - 1997 2.4L
NISSAN STANZA 1990 - 1992 2.4L
