See why some 57's used Commercial spark plugs

[Roy B.]

They said commercial stamped in the white porcelain and heat rang on those Hot Rod 57's, do the JM say so? NO!

[Garry Barnes]

Re: See why some 57's used Commercial spark plugs

Roy, you continue to amaze me. Thanks!
Garry

[Clem Z.]

Re: See why some 57's used Commercial spark plugs

the "commercial" plugs had a much larger electrode and ground strap than the std plug. i would guess that was to prevent the eroding away of these pieces as fast as the std ones when racing

[William C.]

Re: See why some 57's used Commercial spark plugs

With all due respect, it says that a few cars used 46-5 and previously 44, now AC-46 after 4-9-57. It makes no mention of the "com" series having been factory installed, it simply provides a service number for dealers requiring a source for the plugs under specific usage conditions, thus the JG would appear to correctly not mention the "com" series plugs.

[Roy B.]

Re: See why some 57's used Commercial spark plugsB

Bill!
that's my point , I dint say the Factory installed them, this is just a info page or what ever you wont to call it. I did say NO?????

[William C.]

Re: See why some 57's used Commercial spark plugsB

I guess I don't understand the JG reference in your message, as you say the TSB is unrelated to factory installed condition, and the JG is correct in that respect?

[Roy B.]

Re: See why some 57's used Commercial spark plugsB

One more time the Corvette dint come out of the factory with commercial plugs installed , It was a later up date for the dealer .That is what my pic. is telling people. But again 56 used the same plugs as 55 , no groves or green rings, 57 also plug design was the SAME!

[Mike E.]

Re: See why some 57's used Commercial spark plugsB

Roy,
I'm still trying to sort this out in my head. So, are you saying in your first post on this thread that the JM is correct, because it doesn't say anything about the commercial plugs being used, which they weren't?
To me, that's a little bit like saying they didn't used cylinder heads off a 348, because they didn't.
Maybe I missed the point of the first post regarding the JM. Fill me in, please.
Mike

[Clem Z.]

back in the late 50s and early 60s people

who raced corvette were just run of the mill people not the big high dollar teams you see today. when a customer who raced his corvette on sunday and drove it to work on monday came into the dealer for info why his plugs did not last thru the race GM sent these bullitins out to help the grass roots racer because they knew it would help sell corvettes and back then corvettes were not big sellers. remember the motto back then was,"win on sunday sell on monday".

[Roy B.]

Re: See "MIke" 57's used Commercial spark plugsB

YES! YES! That is correct Not in the JM and should not be there.Sorry I dint say it wright I guess! Hope this is understood. "Clem" I cant say that last name right is also right!!