Oops, I meant to say I use the NGK R56707. CB From: C Bilter Sent: Sunday, August 11, 2013 3:23 PM To: Andy Mikonis Subject: Re: [Chrysler300] 300-F Plug reccomendations Andy and all- The ‘62 shop manual, printed in Aug. 1961, specified Champion J12 Y for the New Yorker and Imperial 413s with the Chrysler distributor and Auto-Lite A32 for the Auto-Lite built double breaker distributor used on the 300H and 300 Sport with 413. The 300H owners supplement specified Auto-Lite A32 or Champion J9Y as an alternate. By ‘63, Champions were specified across the board with J12Y for the NYer and Imperial and J9Y for the 300J and 300 sport with 413. An A/C R43S plug is roughly equivalent to an Autolite 84, Champion RJ12YC, or NGK XR5. In the NGK racing plug, that would be a R56705. So the plugs that Tony talks about are 2-3 heat ranges colder than that. I use the NGK R56705 in my J. Tony uses the R56708 in his F. Spark plug x-ref data can be found here, but it is cumbersome to sort through it: http://www.angelfire.com/extreme4/skidoolympique/SPARK_PLUG_CROSS_REFERENCE.htm 300ly, Carl Bilter From: Andy Mikonis Sent: Sunday, August 11, 2013 12:27 PM To: chrysler300@xxxxxxxxxxxxxxx Subject: Re: [Chrysler300] 300-F Plug reccomendations I have used AC R43S a lot in the G over the years. My mechanic mentor in the 80s got me started on AC plugs for big blocks. He said he used them because his new 426 Street Wedge would crank for a long time before starting when it was warm, so he switched to AC and it would fire right up. He actually recommended R45, so the R43S is two steps colder. That said, I've run Champions since George rebuilt my G engine. George always used Champions. I think I've changed them once since and they seem fine, though I suppose it does crank over a long time when warm sometimes. Haven't tried to source the ACs for a while, so I'm not sure if you can still get them. I'm going to try the NGK next. I had saved Tony's info on this. Also, the previous owner of my E-Type installed NGK and they still looked brand new last time I checked. Carl, I thought Chrysler switched to Champion in late '61? Maybe not for 300 engines? Interestingly, the AMA specs for the "300G with Power Pack" (that would be the optional engine) list Autolite A901 or Champion J79. You could always mix brands on either side like Gregg Ziegler and his mechanic did by accident in advance of his record-setting Flying Mile run on Daytona Beach! Andy M. 300 editor - it's not too late to submit a 300B story! On Aug 11, 2013, at 9:17 AM, "C Bilter" <mailto:cbilter%40mchsi.com> wrote: > Champions were not original equipment spark plugs for letter cars until the ‘63 300J. Prior to ‘63 Auto-Lite plugs were used. The original equipment spark plugs on the F &G were the Autolite A32 which are no longer made. The modern day equivalent is “roughly” the Autolite 85. The equivalent Champion is J12YC or RJ12YC. The heat range on both these plugs is right in the middle between hot & cold. The problem is one cannot absolutely compare the heat range of one manufacturer to another, and all manufacturers simply specify a range from hot to cold without any absolute values; it is simply a relative measurement. Furthermore, with today’s gas in the USA, a colder range plug is sometimes necessary to prevent detonation (“pinging”). Ethanol gas tends to make matters worse. The goal is to use the coldest range plug possible without fouling the plugs. > > To that end Tony Rinaldi’s discussion in prior posts about using NGK racing plugs has much merit. NGK offers colder range plugs and they do not foul up. I’ve been using the NGK 7 series in my J this year so far with excellent results. The NGK equivalent heat range of the Auto-Lite 85 and Champion RJ12YC would be NGK 5 series; so I’m running two heat ranges lower on my J. Previously using Champ RJ12YCs gave me nothing but detonation. The original factory plug on the J was a Champion J9Y so it was quite a cold range plug. The F & G in stock form might do fine on an NGK 6 series plug. With a rebuilt engine (no carbon buildup) the Autolite 85 might do fine as well. Champion plugs these days, IMHO, aren’t what they used to be years ago. > > 300Jly, > Carl B > > From: Richard Osborne > Sent: Sunday, August 11, 2013 7:29 AM > To: David Schwandt > Cc: mailto:mailto:Chrysler300%40yahoogroups.com > Subject: Re: [Chrysler300] 300-F Plug reccomendations > > Hi David, I believe the "pipe cleaners" are the side seals for the rear seal retainer. They may need trimmed if I remember correctly. > > I know I'll get static for this, but.... Champions were original equip for Mopars. I have always had best luck with them, even though, to my knowledge, the original heat ranges are no longer available. As a side note to this, be aware that the computer system at Auto Zone has the wrong part number in their system. I have advised a personal friend who is a District Manager, but who knows if it'll get fixed. You'll want RJ12YC, NOT the RN12YC which is a small block Mopar plug. I know this because I bought a set for the G a few days ago. And , yes, I am a geek for remembering some of this nonsense. > > Back off to the races with my son. > > Richard > > Sent from my iPhone > > On Aug 10, 2013, at 9:24 PM, David Schwandt <mailto:finsruskw%40iowatelecom.net> wrote: > > > Well the F is going back together. Got the short block pretty well put > > together except for the rear > > > > Main seal retainer and pan. Darn gasket kit had no side seals for the > > retainer, just a couple short pieces of pipe cleaner!! > > > > WTH is THAT for??? > > > > Wondering what you F and G owners are running for spark plugs these days. > > > > When it 1st went together back in '84 I ran Champion Platinum Plus and > > witched to > > > > Autolite P85's somewhere along the line. > > > > What say you guys?? > > > > Dave Schwandt > > > > [Non-text portions of this message have been removed] > > > > > > [Non-text portions of this message have been removed] > > [Non-text portions of this message have been removed] > > [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! 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