Author Topic: Which spark plugs are available for original 302's??  (Read 12581 times)

69Z28-RS

  • Hero Member
  • *****
  • Posts: 3030
  • owner since 4-Apr-1976
    • View Profile
Which spark plugs are available for original 302's??
« on: March 18, 2009, 05:22:41 PM »
The '69 Z28 used AC43 (non resistor) plugs originally, but I just tried to buy some at a NAPA store, and R43 was all they had.  And they didn't have solid core spark plug wires..  I'm trying to put my original 302 back 'as original' as I can get it...   so I need some help from people who recently went thru this on which spark plugs, wires, dist cap, etc...  to run..    which work well, and lose fewest points in original class judging...   Is running carbon core (resistor type) wire and resistor plugs an issue?   (I've ran solid core silicone wires for 40 yrs, so I'm not very current on what is best or available..   :)
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

1968RSZ28

  • Hero Member
  • *****
  • Posts: 5265
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #1 on: March 18, 2009, 05:51:12 PM »
The '69 Z28 used AC43 (non resistor) plugs originally, but I just tried to buy some at a NAPA store, and R43 was all they had.

Here's a set of AC43 spark plugs on Ebay now...

http://cgi.ebay.com/ebaymotors/1967-68-Chevrolet-Camaro-Z-28-AC43-Spark-Plugs-NOS_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQitemZ140211561422QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Paul

69Z28-RS

  • Hero Member
  • *****
  • Posts: 3030
  • owner since 4-Apr-1976
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #2 on: March 18, 2009, 07:10:08 PM »
In looking at those plugs, which were advertised as '67-68 Z28 plugs.... and a few other ads..  it appears 1969 may have been the first year for Resister plugs.....   and if so, my memory (old).. has failed me again.    Can someone with factual information on original type plugs straighten me out? 
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

1968RSZ28

  • Hero Member
  • *****
  • Posts: 5265
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #3 on: March 18, 2009, 08:11:04 PM »
In looking at those plugs, which were advertised as '67-68 Z28 plugs.... and a few other ads..  it appears 1969 may have been the first year for Resister plugs.....   and if so, my memory (old).. has failed me again.    Can someone with factual information on original type plugs straighten me out? 

My '69 Chevrolet P&A list the following...

'67 - 68 Camaro 302cid . . . . . 5569857  (AC-43)
'69 Camaro 302cid . . . . . . . .  5569992  (AC-R43)


Paul

1968RSZ28

  • Hero Member
  • *****
  • Posts: 5265
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #4 on: March 18, 2009, 08:17:43 PM »

69Z28-RS

  • Hero Member
  • *****
  • Posts: 3030
  • owner since 4-Apr-1976
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #5 on: March 19, 2009, 05:09:17 AM »
Thank you Paul!
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

RamAirDave

  • Member
  • ***
  • Posts: 334
    • View Profile
    • TheMuscleCarGuys.com
Re: Which spark plugs are available for original 302's??
« Reply #6 on: March 19, 2009, 05:38:34 AM »
As far as what is available at the parts store, the R45S is recommended per JohnZ's tune-up specs, as well as others' experience.
"Build them how the designers and engineers envisioned them to be"

www.TheMuscleCarGuys.com

Larry

  • Member
  • ***
  • Posts: 59
    • View Profile
    • 1968 Camaro Z 28 Rally Sport
Re: Which spark plugs are available for original 302's??
« Reply #7 on: March 19, 2009, 01:35:00 PM »
AC 43 plugs are hard to find. Some aftermarket suppliers have R43 plugs available. The AC R45S plugs are available from NAPA and other parts suppliers.

Larry

JohnZ

  • CRG Member
  • *****
  • Posts: 4279
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #8 on: March 19, 2009, 06:25:14 PM »
43's are WAY too cold for normal street use - they'll foul regularly. 44's are a little better, but the 45 heat range is trouble-free. I run R45S plugs in all my vintage small-blocks, and have for years. My '69 Z/28 runs stock carbon-core wires, stock coil, and Accel #110128 28-32 oz. points, with zero issues. Stock points are 19-23 oz., and break up over 6000 rpm.
'69 Z/28
Fathom Green
CRG

Jerry@CHP

  • CRG Member
  • *****
  • Posts: 1457
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #9 on: March 20, 2009, 02:16:34 AM »
Use Champion J12-YC.  Same as AC44's.  These are the best for street performance and driving.  Like John said, 43's are too cold for the street.

We use these in many customer's cars,

Jerry

Jerry@CHP

  • CRG Member
  • *****
  • Posts: 1457
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #10 on: March 20, 2009, 12:57:27 PM »
Rergarding the 302 engine, when using AC45's in the hot weather, there are knocking issues when accelerating hard.......even with timing set at 36 total degrees.  NG! 

They're fine if you don't throttle up.  J12-YC Champion is best all round perf.

Jerry

69Z28-RS

  • Hero Member
  • *****
  • Posts: 3030
  • owner since 4-Apr-1976
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #11 on: March 20, 2009, 09:18:50 PM »
Champion J-12YC is what I always used when I was driving my car; I never liked AC plugs!   but...  in trying to put my car back in 'production trim', I assumed I would need to use the original plug type...   Are plugs judged or not?
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

jdv69z

  • Hero Member
  • *****
  • Posts: 739
  • 69 RS Z/28 52E
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #12 on: March 21, 2009, 02:50:48 PM »
What's the difference between resistor and non resistor plugs?  IE Champion J12YC and RJ12YC?

Jimmy V.
Jimmy V.

Jrschev

  • Member
  • ***
  • Posts: 69
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #13 on: March 21, 2009, 11:42:56 PM »
Resistor spark plugs were a result of an FCC requirement to eliminate or reduce radio and TV interference from automobiles. They have no other function in your ignition system and, in fact, create another voltage drop on the high tension secondary side of the ignitioin system. You can run non resistor spark plugs without any issues what-so-ever as long as you are not trying to listen to the radio or watch TV at the same time! It's also important to understand that this requirement was enacted back when TV signals were "broadcast" and reception was via antennas.

The frequency of the ignition system is in the same spectrum as TV and radio signals. Years ago cars would drive by someone's home and the TV would have all kinds of static on it from the EMI of the car ignition driving by. The same was true of people listening to the radio nearby or even in a car adjacent to you. All of this brought forward the FCC ruling that required manufacturers to comply to a reduction in EMI. Cheapest way out was resistor spark plugs. If you want peak performance do not use resistor spark plugs. You will get the maximum voltage drop at the electrodes this way. If you plan to listen to the radio at all in your car I would, however, advise you to use resistor spark plugs.

The best thing you could ever do to increase the performance of your ignition is eliminate the points. there is nothing good about points. Thats why they were eliminated in the 70s. You can purchase an electronic module (transistor) that will fit where you points were and effectively do more to increase the output of your ignition than any other modification. No one will ever know because it will be hidden inside your distributor cap. You could rev the engine to 100,000 rpm and you wouldn't come close to out running a transistor.
1969 Z11 Pace Car (05A) 350/300 L48 4-Speed

Dave69x33

  • Member
  • ***
  • Posts: 352
    • View Profile
Re: Which spark plugs are available for original 302's??
« Reply #14 on: March 22, 2009, 03:08:42 AM »
I have to agree with Jrschev regarding switching to electronic ignition.  I installed the Pertonix Ignitor II Electronic Ignition conversion kit #91181, and the black Pertronix Flame-ThrowerII low resistance 0.6 ohm coil several years ago.  I noticed an immediate improvement in starting and drivability of the car.  Plus, the Pertonix unit is hidden.  With a little work, you can modify and retain the original ignition wiring so it looks stock.  See picture.

For a little added benefit, I modified a set of Delco 8mm spark plug wires for a 1988 GM/GMC 5.7L Truck.  These plug wires utilize the "spark plug" style terminals on the cap.  However, I modified the wires to push into the standard cap and replaced the boots to straight original style boots.  I had an 88 GMC years ago which is where got the idea.  The plug wires route in the same positions as the original plug wires and they look very stock.  I have not had good luck with the reproduction plug wires so I like the GM 8mm wire set for better reliability.

This is my "driving set-up".  When I attend a “points show” or Camaro Nat's, I swap back to my #270 coil and correct NOS cap and plug wires.  I keep the correct wires on the NOS cap so it's ready to go and an easy swap.