Which Spark Plugs? - CorvetteForum - Chevrolet Corvette Forum Discussion



C1 & C2 Corvettes
General C1 Corvette & C2 Corvette Discussion, Technical Info, Performance Upgrades, Project Builds, Restorations
Sponsored by:
Sponsored by:

Which Spark Plugs?

Reply
 
 
 
Thread Tools Search this Thread
Old 02-18-2007, 08:10 PM   #1
Sky65
CF Senior Member
Support Corvetteforum!
St. Jude Donor '05, '09, '15
Thread Starter
 
Sky65's Avatar
 
Member Since: Nov 2003
Location: Maryland
Posts: 4,273
Thanked 60 Times in 53 Posts
Default Which Spark Plugs?

My car is a 65 but I have a 69 350 engine. I was looking at the AC Delco web site and looked for spark plugs by model. A 66 Corvette, doesn't have 65, 327 calls for R45S. A 69 350 Corvette calls for R43S. So. Which plug do I use? I would think the R43S to match the engine. However. I looked the C3 section and the recommended plug there seems to be the R45? Thoughts?
Sky65 is offline   Reply With Quote
Old 02-18-2007, 08:14 PM   #2
MikeM
CF Senior Member
 
Member Since: Mar 2003
Posts: 18,549
Thanked 251 Times in 225 Posts
Default

Quote:
Originally Posted by Sky65 View Post
My car is a 65 but I have a 69 350 engine. I was looking at the AC Delco web site and looked for spark plugs by model. A 66 Corvette, doesn't have 65, 327 calls for R45S. A 69 350 Corvette calls for R43S. So. Which plug do I use? I would think the R43S to match the engine. However. I looked the C3 section and the recommended plug there seems to be the R45? Thoughts?


R45 or R45S or equivalent in another brand.
MikeM is offline   Reply With Quote
Old 02-18-2007, 09:15 PM   #3
Ironcross
CF Senior Member
 
Ironcross's Avatar
 
Member Since: Nov 2002
Location: Taylor Michigan
Posts: 12,146
Thanked 22 Times in 19 Posts
Default

Ironcross is offline   Reply With Quote
Old 02-18-2007, 09:22 PM   #4
Mark_Milner
CF Senior Member
 
Member Since: Feb 2006
Posts: 4,224
Thanks: 0
Thanked 40 Times in 24 Posts
Default

Quote:
Originally Posted by Sky65 View Post
My car is a 65 but I have a 69 350 engine. I was looking at the AC Delco web site and looked for spark plugs by model. A 66 Corvette, doesn't have 65, 327 calls for R45S. A 69 350 Corvette calls for R43S. So. Which plug do I use? I would think the R43S to match the engine. However. I looked the C3 section and the recommended plug there seems to be the R45? Thoughts?
The original plug for Corvette 327s through '68 was the AC 44. In 1969, it was the R44. The 44 series is not available anymore, but no matter as it was really a bit too cold for normal driving. The 45 series is better.

There is no real performance difference in the 45 or R45. The R is for resistor plugs which help reduce ignition noise in radios. The R45S has an extended tip which helps keep it cleaner from fouling and so it runs a bit better. However, if you have high domed pistons or the heads have been shaved, you could hit. You need to install the plugs, turn the engine over, and then check the plugs if you have any performance work done on the engine.

If you are running the R43S, you'd better be doing hot laps most of the day, because it is far too cold for the street.
Mark_Milner is offline   Reply With Quote
Old 02-18-2007, 09:59 PM   #5
magicv8
9 Hot Rod Power Tours
 
magicv8's Avatar
 
Member Since: Nov 2000
Location: Going too fast over the hill.
Posts: 7,240
Thanks: 0
Thanked 0 Times in 0 Posts
Default

The original setup used nonresistor 44 plugs with resistor wires. If you use resistor plugs such as R45, and you have the original Delco coil, IMO switch to nonresistor wires or bag the original and expensive coil.

The original coil is easily overloaded by resistor plugs used in conjunction with resistor wires. So was the Pertronix Flamethrower thatI replaced it with - that lasted about a year before melting down.
magicv8 is offline   Reply With Quote
Old 02-18-2007, 10:08 PM   #6
Sky65
CF Senior Member
Support Corvetteforum!
St. Jude Donor '05, '09, '15
Thread Starter
 
Sky65's Avatar
 
Member Since: Nov 2003
Location: Maryland
Posts: 4,273
Thanked 60 Times in 53 Posts
Default

Thanks
I am using an MSD distributor, 8.5 mil wires, blaster coil and 6al box so I need the resistor plugs. R45S or equivalent it is.
Sky65 is offline   Reply With Quote
Old 02-22-2007, 11:58 AM   #7
JoesC5
CF Senior Member
 
Member Since: Sep 1999
Location: Springfield MO
Posts: 34,851
Thanked 660 Times in 485 Posts
Default

NGK B4's
JoesC5 is online now   Reply With Quote
Old 02-23-2007, 07:34 AM   #8
paul 74
Ontario, Canada
Support Corvetteforum!
 
paul 74's Avatar
 
Member Since: Aug 1999
Posts: 30,960
Thanked 71 Times in 69 Posts
Default

I agree with Joe. The NGK B-4 is the same heat range as the AC 45 (hard to find) and is non-resistor and non-extended tip.

paul 74 is offline   Reply With Quote
Go Back   CorvetteForum - Chevrolet Corvette Forum Discussion >
Reload this Page
  • Which Spark Plugs?
  •  
     
    Reply

    Related Topics
    Thread Thread Starter Forum Replies Last Post
    Spark Plug seating and types slyfox2062 C3 Tech/Performance 10 12-03-2015 03:33 PM
    Spark Plug HELP PLEASE lou69 C3 General 3 07-15-2015 07:53 PM
    Best Spark Plugs for '69 Vette bucket C3 Tech/Performance 7 02-11-2014 06:12 PM
    Will an AC Delco R45TS spark plug work for a 1985 Corvette 07slvrbullet_z51 C4 General Discussion 5 02-02-2010 12:21 AM
    What's the better spark plug? 67 SB SIXt7 C1 & C2 Corvettes 10 06-17-2006 07:06 PM


    Tags
    1966, 30, 327, 350, 68, ac, chevy, corvette, delco, plug, plugs, r43s, r45, r45s, spark, speck

    Thread Tools Search this Thread
    Search this Thread:

    Click for Advanced Search

    Posting Rules
    You may not post new threads
    You may not post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are Off
    Pingbacks are Off
    Refbacks are Off

    Forum Jump


    All times are GMT -4. The time now is 09:33 AM.


     
    • Ask a Question
      Get answers from community experts
    What's your question?
    Send