69 L46 spark plug
Melting Slicks
Joined: May 2006
Posts: 3,438
Likes: 41
From: Raleigh NC
St. Jude Donor '13-'14
The R45 will work just fine.
Instructor
Joined: Mar 2011
Posts: 176
Likes: 9
From: Uttendorf - Austria
This makes it a lot easier for me and I dont have to order them from overseas right now - so I can wait and see what else I will need for my '53 Olds resto and order all parts together
Melting Slicks
Joined: May 2006
Posts: 3,438
Likes: 41
From: Raleigh NC
St. Jude Donor '13-'14
Melting Slicks
Joined: Aug 2011
Posts: 3,114
Likes: 258
Exactly same scenario as you : Just bought a new "single" and had a fairly old set (minus 1).
Don't know the vintage of the old set - probably 25 years ?
Melting Slicks
Joined: May 2006
Posts: 3,438
Likes: 41
From: Raleigh NC
St. Jude Donor '13-'14
My new R45S are identical in all dimensions as my old R45S. My old one is old enough to have "MADE IN U.S.A. A-22" stamped into the barrel of it.
Are you sure your old one is not an R45 (without the "S")?
Melting Slicks
Joined: Aug 2011
Posts: 3,114
Likes: 258
My new old stock R45S' were made in Canada.
The sleeve pack has ACNITER R45S plus the GM part number 5612028.
Curiously the specified torque is 15 LBS.FT on the package.
The insulator on both sets of plug's : the ones being replaced and the new (old stock) replacement set (minus 1) protrude about 1/32" past the shell.
I don't feel like removing the new store bought R45S but am sure the insulator and center electrode assy protruded at least an 1/8" further.
My new old stock plugs are stamped AC SPARK PLUG followed by a bunch of vertical lines.
I believe I have had these spark plugs at least 30 years, probably longer.
I have a lot of parts I bought new / acquired back in the 70's - bunch of 44 spark plugs, brown distributor caps, TI coils etc
Last edited by QIK59; Jun 25, 2014 at 07:29 PM.
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Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Old thread, but
As for some of you new Vette people, the 'S' means extended tip and will not work with higher domed pistons....The example is that a 1961 FI 315 hp engine is 11.25 compression, not 11.1. ...The correct plug is a #44 as the piston will hit the 44S plugs ....But in the 62`s which are 11.1 which was accomplished for GM by using 2 head gaskets a side....That slim difference is all that was needed to successfully use the S plug in the 360`s ....Not really a well known practice as most 315 cars were taken apart years ago and put back together wit a thicker gasket...Another reason is the 'S' tip only affected the FI Vettes and not the others because of its domed 315 pistons....
but 'whatever'
but 'whatever'
Melting Slicks
Joined: Aug 2011
Posts: 3,114
Likes: 258
Not sure what your old and new look like - but these are mine.
Okay what looks like has happened is that the old plug threaded body below the gasket face was about 7/16" long.
The new plugs are only 3/8" long below the gasket face - they have shortened the body about a 1/16" which has unshrouded the insulator and center electrode - making it look like the nose and center electrode are longer.
The projection into the chamber has remained the same but the last 1/16" of the shell which was not threaded anyway is gone.
Theoretically the plug should perform better and make a bit more power.
Overall the new plugs are a touch longer external to the combustion chamber.
There you go !!
