V8 spark plugs

[Guest Randy Berger]

I can't buy Champion R16NYC plugs. They do have R16NYC5. Is that the same plug? Will ACR45XLS crossover and work just as well?

[Guest Randy Berger]

I've been running RN14YC since 2002 but wanted a hotter plug. Trying to figure out what the 5 means at the end of RN16YC5 <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" /> <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" />

[K8096]

When I got my '55 400 it had Champion H10 plugs in it. Was told they're no longer available & that Champion H10C is the replacement. I'm not saying these are correct, but the car does seem to run fine on them. By the way, not to change the subject, but what octane gas are you guys running in your stock carburated V-8 Packards? Do you stay away from BP gas?

[Guest imported_PackardV8]

Questions and remarks in every post above is CLEAR CUT EVIDENCE that Champion should be avoided. Noone really knows Champions code system and worst of all Champion doesn't even know. Try the Autolite 66 plugs. Probably from Kanter. Maybe Packards1 has some. Or find a cross to AC's.

Also cheque the 55-56 x-ref thread.

Spark plugs is something that should not require alot of R&D and butt scrathing every time they need to be changed. You've got get a brand of plug that has a numbering system that can be trusted over the years. AC holds the exclusive tradition for consistent numbering systems. IT's EZ!!!! LEARN IT!!!! Then u will know what u have or need to get without guessing. IF it's not AC or AL (aka: motocraft, Motovator) then just forget about it. Otherwise u will have a world of bewilederment every time u want to change and/or replace plugs. I've been thru this too many times.

Some people have several sets of Champions and other off brands on the shelf for years or even decades that have proven. So they are not running to the store to try to figure it out or read books and charts. If u can find such a cache of plugs then ok. Otherwise it's AC or Al and NO, NONE OF THAT G**D*** Bosche, or Nip or Log or Spitfire or any other brands either. AC OR AL!!!! It's just that simple. I don't know anyother way to explain it.

[Guest BigKev]

I bought a set of vintage AC 45's to run in my '54. I bought a box of 8 for $12 off of e-bay. The parts stores only carry the R45's. I might buy another box just to have for later on.

[mrpushbutton]

I've never liked Champions. Have had very good response from AC's.

[mlander]

Champion H10 plugs are 14mm by 7/16? reach by 13/16? Hex.

Champion

Traditional spark plug RH10C $2.37

http://www.densoiridium.com/identifyplugs.htm Chart explaining the Denso marking system. Denso equivalent H-10 Equivalent = W 16 LS

http://www.ngksparkplugs.com/apps/car_truck_suv/results.asp Chart explaining the NGK marking system. H-10 Equivalent = B6L

I can?t find a plug for GM DELCO to replace a Champion H-10 for sure but

It is likely to be an AC-44 or 45

Here is an address that claims it has the H 10 above equivalent.

http://www.championsparkplugs.com/result...nCrossWarning=1 R = Resistor C = Copper Core = RH10C

M.L. Anderson

[mlander]

B.H.

Member

Reged: 08/15/01

Posts: 2645

Loc: Western PA Re: V8 spark plugs

07/19/06 11:08 PM

While my dad was always big on AC plugs in his Packard, I never had a problem finding the Champion plugs, and the N16YC (in the 56, H10 in the 55) seemed to run great.

The Champion N16YC = 14mm by ¾? reach by standard Projected Core by copper.

BH I am hoping that no one puts these plugs into a tapped hole that is supposed to receive an H10 plug as the difference in the reach is 5/16? . I don?t know if this would hit the piston or not but has no application in a place that had an H10 Champion. I hope no one tries this as it might just be disastrous. What was the original sparkplug for that year of V-8?

Yours M.L. Anderson

[mlander]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I've been running RN14YC since 2002 but wanted a hotter plug. Trying to figure out what the 5 means at the end of RN16YC5 <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" /> <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" /> </div></div>

R = Resistor, N =14mm by 3/4" reach, 14 is the heat range, Y = Standard Projected, C= Copper, A 4,5,6 or 8 means a wide gap required to meet Federal and California specification requirements.

M. L. Anderson <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />

[Guest Randy Berger]

Thanks Mlander, but what gap does 5 indicate?

[Guest Randy Berger]

Brian, a friend and I went to the Butler parts-a-rama several years ago and he spotted a box of N-18s lying upside down on a table and pointed them out to me. They were already obsolete at that time and Champion didn't even show a listing for them. I bought the whole box for $.50 a piece. Then the vendor asked me what they were for as he had been carrying them around for years.

I told him they were for my car <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" /> <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" /> <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" />

Sometimes it's fun to be a smart-arse.

I still have them in the box - never used them.

[Twitch]

Mr. Pushbutton, nice to know. I have an Autolight alleged equivelent in now but figure the AC 45s are exactly the right heat range and all for it.

Just curious, but has anyone gone into a regular auto parts store and asked for vintage plug designations just to hear the answer?

[mlander]

Champion N-18. = 14mm by 3/4 reach by 13/16? hex by 18 heat range number.

Champion

Traditional spark plug RN14YC

R = Resistor, N =14mm by 3/4" reach, Y = Standard projected core nose, C = copper plug design.

To Randy Berger; the Sparkplug Chart I have doesn't state the actual gap just that it was a special gap.

I guess it is in the Shop and Tune up manual!

[Guest imported_PackardV8]

OK. So apparently the numeric value of the champion plug is the heat range. SO, if ONE heat range hotter is desired then what do we do????? Add 1 to the numeric value???? Subtract one?????

[mlander]

PackardV8

Re: V8 spark plugs [Re: mlander] #411595 - 09/28/06 09:01 AM

OK. So apparently the numeric value of the champion plug is the heat range. SO, if ONE heat range hotter is desired then what do we do????? Add 1 to the numeric value???? Subtract one?????

Without the Champion sparkplug chart @

http://www.spark-plugs.co.uk/pages/technical/champion_symbol_code.htm

Iit is impossible to state just what a number or letter means but you have to be very careful about all heat numbers as some Japanese makes number from the lesser to the greater and some from the opposite direction. This is an old chart and difficult to read but is well worth the effort to decipher if one has the time and patience to do so.

The best(?) information I have is that Champion numbers on regular automotive plugs is as follows, the lower numerical is cold and higher numerical are hotter. The Champion numbers for regular Automotive, Small Engine plugs should be 1(Cold) - 25(Hot).

Aviation plugs are from 26-50. Hi performance plugs are 51-75.

Industrial & Special Application 76-99.

Yours, M. L. Anderson

[Guest imported_PackardV8]

Thanks for UK link. AND from the SAME site :

http://www.spark-plugs.co.uk/pages/technical/Champion_supercessions.htm

NOTE that the heat ranges in the supercession link above contains WIDE variations. TO-wit: i refer everyone to my #394671 - 07/19/06 10:30 PM post above. It is not clear to me why so many car owners are fighting this Champion spark plug issue. This is like spending $50/hr time on trying to streighten a bent penny . Unless of course someone has several tons of bent pennies at their disposal.

I'm not trying to be sarcastic nor demeaning. I really do not understand why so many are so hell-bent for Champion. I throw them away.

[Guest imported_Speedster]

Brian, Thanks for the Plug Info. <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />

[Guest imported_PackardV8]

BH wrote: "That numbering system seems to have gone out the window in the past decade; the new short numbers for spark plugs (e.g. - #41-902) make no obvious sense to me."

That's news to me but then again i've not bought any plugs for anything newer than 1989.

Tha AC plug coding system is EZ. There are only 2 numeric positions and the rest are alphabetic.

The second DIGIT is the heat range and runs only from 2 thru 6. 2 is COLD, 6 is hot.

The FIRST digit is the millimeter of the thread. 4 is 14 mm, 8 is 18 mm, 1 is 10 mm and so forth.

SO, an AC 44 is a 14 mm plug mid temp. An 83 is an 18mm slightly colder than average.

This is all clearly explained on about 2 pages in front of nearly all AC Delco books i've seen ca 1958 thru about 1979. I currently have a 1975 edition that i am sure glad i saved.

[Guest imported_PackardV8]

BTW, the above explanation i have has been true about AC"s since 1955 that i know of and probably even earlier than that. It's too bad they changed over the last 10 years but guess what, i doubt that i will need to worry about any spark plugs for anything newer that 95 or 96 any way and when i do it WILL BE AC's.

[Guest JT]

To confuse things more the old AC 104 plug, that is a 10mm, is now an M8 which doesn't really seem to fit into their description chart very well.

M= marine and 8= I guess the heat range?

[mlander]

Randy; I finally found out that the 5- mean a-.050" gap, .6- means .060" gap & 8- means .080" gap.

These are gaps that require a HEI ignition so as to fire those large gaps.

Edit; If you wish to have a copy of the Champion sparkplug chart here it is at;

http://www.spark-plugs.co.uk/pages/technical/champjpg.htm

If you wish to see some old drawings of old plugs see this;

http://home.comcast.net/~m9a3r5i7o2n/SPARKPLUGSG14-G12-G6.JPG.html

Yours, M.L. Anderson

[Guest Randy Berger]

Mr. Anderson, your diligence and research is much appreciated <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" />

[Guest imported_Speedster]

Yes, Great Info, Thanks <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />

[mlander]

N-18 = 14mm # 18 heat range and ¾? reach.

N19C_ = 46XL = 14mm by #6 heat range, by X = fine wire by skirted shell firing end 200? Core nose

N16YC = 46XLS = 14mm by #6 heat range, by X = wide gap, by L =Long Reach, by S extended tip.

N14Y = 45XLS = 14mm, by # 5 heat range, by X = wide gap, by L =Long Reach, by S extended tip.

CR = commercial + resistor

Delco AC plugs if the plug has no suffix it probably means that it is a ?Normal? reach plug, on a 14mm this means 3/8? reach. However you have to watch out for the suffices shown below, example N & S.

No Letter means 3/8? reach on 14mm.

F = means ½? reach on 14mm.

FF = means ½? reach but fully threaded, that is no undercuts on thread.

L = 7/16" reach on 14mm.

XL = 3/4" reach on 14mm.

Champion H10 =14mm by 7/16? reach, no heat range given = Delco AC 45L = 14mm by #5 heat range by 7/16? reach.

New designation = RH10C = Resistor + 14mm by 7/16? reach + Copper core.

For more on Champion plugs go here, but note that this is a British Champion chart.

However it is very informative IF you study it very carefully!!!

http://www.users.on.net/~geosurveys/charts.htm

This chart is an American Champion sparkplug chart.

http://www.spark-plugs.co.uk/pages/technical/champjpg.htm

These are Autolite charts.

http://www.autolite.com/pdf/auto_crossref_0311.pdf

http://www.autolite.com/pdf/auto_se6_0406.pdf

http://www.autolite.com/pdf/auto_prinapp_0112.pdf

http://www.autolite.com/pdf/autolite5_ce7_1217.pdf

B.H. Quote; Also, in addition to the "4" (14mm) and "8" (18mm), designations for thread size, I believe there was also "10" and "11" listed.

Brian

Brian; you were right in looking up the GM Delco chart.

Therefore I will continue to post stuff that you can understand and appreciate from the chart.

# 1, the 10 was not a ten but a ?1? meaning a 10mm plug which AC still makes although I have never seen any. This is the plug that caused a big fiasco about 1939 on Buick & Chevrolet. Packard also used it I understand but never seemed to have a problem with it to my knowledge. The " 0" I believe was made in anticipation of more heat numbers,which did not occur!

I don?t believe that AC ever made a 1/2 n.p.t. for old Ford Model T?s to my knowledge and I haven? seen any listing on the charts that I have. Altho in the listing on Ford there is a call-out of a ?28? which may or may not be a ½? n.p.t. sparkplug.

# 2, The number ?7? means a 7/8?-18 threaded sparkplug and is an old designation from around the 1920?s or even earlier but was dropped in favor of the 18mm around 1930 which was dropped in 1932 in favor of the 14mm sparkplug.

The reason I drew the sparkplugs of the ?G? series is due to my study of the Oakland-Pontiac V-8 of 1930-31-32 which used this sparkplug in 1930 & 1931 and the 1932 Pontiac used 14mm ?K? series sparkplugs. Later somewhere in the middle 1930?s they changed the numbering system very near to the system they use now. For some reason, of which I don?t have any information, Oldsmobile and Pontiac never seemed to get caught up in 10mm fiasco. Just why this was so I haven?t been able to discern.

Packard used this 10mm ?# 106? sparkplug but never seemed to have any problems with it that I ever heard of. I have never seen one!!!

Yours M.L. Anderson

[Guest JT]

M.L.

The AC replacement for the 106 is an M8 plug. I know they are still available through NAPA but whether or not AC is still making them is a good question. Also there is only the one heat range available now whereas before they had a 104, 106 & 108 to choose from.

I think there is a Packard TSB concerning 10MM plugs fouling (oil) and heads being rethreaded for 14MM plugs.

[Guest imported_PackardV8]

Someone wrote: "N=on a Delco AC means a ¾? reach, 3/8? Reach but doesn?t state just which sparkplug.

S on a Delco AC sparkplug means a skirted shell. "

According to my AC book dated January 1976 for the following SUFfixes:

" N - extra long reach (14 mm.) (3/4 inch reach with 3/8 inch thread length)"

" S - Extended tip"

" S - (7/8inch) Moderate long reach (23/32 inch)"

NOTE: that there are also PREfixes. One of which is an "S" which is "Sport Vehicle". And ealier an "MC" for motorcycle which by 1976 was included as "S" and the "MC" dropped.

AC Delco PREfixes tend to describe plug application. SUFixes describe plug characteristics.

[Guest imported_PackardV8]

mlander wrote: " don?t believe that AC ever made a 1/2 n.p.t. for old Ford Model T?s to my knowledge and I haven? "

Unless one is restoring to exacting production then the NPT should not be a big issue.

Any of the 6 or 8 national Indian dealers can supply a BRASS insert that is 1/2 npt weith 14 mm thread in the centre. OR just go to the hardware store and buy a reducer in the plumbing section and drill it out for a 14mm thread. I've done it several times for Indian.

[Guest imported_PackardV8]

Did the 56 Golden Hawk (with Packard V8) use the 55 heads or the 56 heads????

[Guest imported_PackardV8]

From my AC Delco book dated 1976:

Packard 1956-55.......V8 7/16" Reach.........43LS gap.035.

........................ 3/4" reach R45XLS or 45XLS gap .035.

Note that the "LS" means:"L" = Long reach (7/16" for 14mm.).

........................."S" = Extended tip.

.............."XLS" means: "XL" = extra long reach (3/4' for 14mm).

.......................... "S" + extended tip.

BUT FOR Studebaker Golden Hawk 1956 R44XLS or 44XLS gap at .035.

I'm using Autolite 66 in my Executive.

[Guest imported_Speedster]

Hey, I'm starting to Feel like a Spark Plug Expert, with all this Great Info. <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" /> Guess I better do a printout of this thread, before I forget it all. <img src="http://forums.aaca.org/images/graemlins/shocked.gif" alt="" />

Thanks.

[mlander]

PackardV8; I have a copy of the Audels sparkplug chart of around 1935 which shows the relation of the old 7/8-18, 18mm and some K series 14mm plugs. The K (14mm) series seems to be the one that preceded the 4 (14mm) series of plugs.

I need some one that can check the additions I have made to it to see if I am correct in my additions to the chart from the K series to the new 14mm chart. This is the point of contention as I have never seen a chart that does this. This chart seems to be a copy of an old Delco AC chart. Unfortunately it did not include a transfer over to the newer AC designation. I need someone to check my work!! This is due to the difficulty of finding the ?secret? of the reach designations. I believe I am right, but you can see how that goes.

If you can feel safe to send me you E-mail address @ m9a3r5i7o2n@comcast.net I will attempt to send a copy of it to you post haste.

I made this copy about two years ago but have not felt comfortable to place it on the Internet as no one has tried to verify my additions to it.

When copying it I had it to draw it on Legal, 8 ½? x14?, paper so we may have some difficulty in doing this. I have never tried this before, therefore I don?t know if it is possible or not. It was drawn with Autodesk/AutoCad but a very old version and since these programs are so expensive I have never updated it at $3,600 a crack.

Yours, M.L. Anderson

[mlander]

R16NYC plugs. They do have R16NYC5. Is that the same plug? Will ACR45XLS

Should be RN16YC, RN16YC-5 and R45XLS not as shown above!!!

The reason I couldn't get the above numbers to work is they have the letter "N" in the wrong place when I put the letter "N" in the correct place they work perfectly. Same also holds true with the AC after removing the letters AC it also works perfectly in the address below.

http://www.sparkplugs.com/default.asp

The callout in the book states that the plug for this is a Champion N18 which is replaced with the Champion RN14YC = Resistor plug, 14mm, 3/4" reach, 13/16" hex head, projected tip, copper core.

M.L. Anderson