1976 New Yorker 440 spark plug help

[fakirone]

Alright, I've resorted to asking.

I pulled the plugs on my New Yorker because it's been running a little rough. They were very dirty and generally looked old and worn. So I decided time to get more.

Here's the problem, the plugged I pulled is a shorty plug. I'm all my days I have never worked on a vehicle that had shorties. So, did some online looking, seemed that the general consensus for plug for this car are Champion RN12YC. Got them ordered and they arrived today. They are not short style.

I have a frigging manual and I cannot find a mention of a part number for plugs, took me forever to find the gap as it's just randomly inserted into the engine performance section.

Does this car need shorty plugs, if it does which ones do I need?! Or are these Champions good to go (once gapped of course)?

Thank you in advance.

 

[SwissMonaco]

The correct plugs for the 440 with this year are with a short thread and a cone for sealing. The correct number from Champion is RV12YC

 

[Vaanth]

Alright, I've resorted to asking.

I pulled the plugs on my New Yorker because it's been running a little rough. They were very dirty and generally looked old and worn. So I decided time to get more.

Here's the problem, the plugged I pulled is a shorty plug. I'm all my days I have never worked on a vehicle that had shorties. So, did some online looking, seemed that the general consensus for plug for this car are Champion RN12YC. Got them ordered and they arrived today. They are not short style.

I have a frigging manual and I cannot find a mention of a part number for plugs, took me forever to find the gap as it's just randomly inserted into the engine performance section.

Does this car need shorty plugs, if it does which ones do I need?! Or are these Champions good to go (once gapped of course)?

Thank you in advance.

The correct Champion spark plug as specified in 1976 for a 1976 440 standard car engine was RJ13Y. For a 1976 440 high performance was Champion RJ11Y (alternate J11Y non-resistor). The current Champion replacement for these spark plug numbers is RJ12YC or RJ12Y. The "C" denotes a copper core electrode. Champion, and others, have consolidated heat ranges.

Some alternate brand crossover plugs include the following:
- Autolite 85 (or 75 non-resistor)
- NGK BP5S or BPR5S
- Accel 0437 or 0437S
- Denso W16PR-U or W16PRU
- Bosch W7FC
- AC R44S (or 44S, B44S non-resistor)

Mopar numbers for the original numbers are as follows:
- J11Y = 34P or 2642913
- RJ11Y = 34PR or 2642989
- RJ13Y = 35PR or 3438334

NOTE: RN12YC is a 3/4" reach plug used in many small block applications including LA318 and 360 engines. RJ12YC is a 3/8" reach plug used in big block wedge engines including 440 car engines.

 

[Big_John]

Or are these Champions good to go

These guys have covered what plug you need, but I feel like it should be stressed NOT to use these plugs. They are for a small block (318, 360 etc.) and will damage the tops of the pistons in a big block (400, 440 etc.)

I have a frigging manual and I cannot find a mention of a part number for plugs, took me forever to find the gap as it's just randomly inserted into the engine performance section.

It should be in the back of the Chassis manual electrical section, under "specifications". I don't have a '76 manual to tell you the exact page. I believe there are two manuals for your car, one "chassis" and one "body".

 

[CBODY67]

I'm not sure what the prior owner did, or why, but the long-reach LA motor plugs never have been installed in the B/RB motors at any time in their life. Maybe a bad auto supply parts person? Or a bad "guaranteed to fit, with modifications" eBay listing?

The saving grace might have been the .125" deck height of the 440 pistons at TDC? But that's still a big difference in the thread length.

Tapered seats on a Chrysler B/RB motor? When and if did they change from the gasketed plug (J-13Y) to them? "R" for resistor is not an issue in this.

Spark plugs have been listed in the "Specs" section of the "Ignition" section of the factory service manual, with the distributor advance specs and basic timing setting listings. "Tune Up" listings. In the pre-1966 FSMs, all of the specs were at the back of the manual, rather than in the section which they applied to.

@Big_John and @Vaanth are completely correct in the above comments as to spark plug usage.

Now, all of this is presuming that the stock-type cast iron cyl heads are still on the motor! Not some aftermarket aluminum cyl heads, which can use different-than-stock spark plugs.

ACCEL used to make some "shorty" spark plugs for spcific Chrysler 440 motorhome applications. Same heat range, just shorter "outside" ceramics where the plug wires attached, for clearances in the tight "dog house" engine cover.

Take care,
CBODY67

 

[fakirone]

These guys have covered what plug you need, but I feel like it should be stressed NOT to use these plugs. They are for a small block (318, 360 etc.) and will damage the tops of the pistons in a big block (400, 440 etc.)


It should be in the back of the Chassis manual electrical section, under "specifications". I don't have a '76 manual to tell you the exact page. I believe there are two manuals for your car, one "chassis" and one "body".

My manual is actually two books, one for body and mechanical, the other is for electrical.

 

[Big_John]

My manual is actually two books, one for body and mechanical, the other is for electrical.

I remember that now.

I think they went to 2 books in 1971. Those were chassis and body. Somewhere along the way, they went to body and electrical. Maybe 1975?

 

[CBODY67]

The 1978 Chrysler FSM I bought at a swap meet is one book as the 1970 FSM is (for my DH43N0D), my '66 and '67 Chrysler books are. Same format in all of them. Spark plugs listed in the "Ignition" section. Perhaps, in some years, they made two books as some dealers didn't need "everything"? FWIW

 

[fakirone]

I remember that now.

I think they went to 2 books in 1971. Those were chassis and body. Somewhere along the way, they went to body and electrical. Maybe 1975?

 

[fakirone]

The correct plugs for the 440 with this year are with a short thread and a cone for sealing. The correct number from Champion is RV12YC
View attachment 713799

The correct Champion spark plug as specified in 1976 for a 1976 440 standard car engine was RJ13Y. For a 1976 440 high performance was Champion RJ11Y (alternate J11Y non-resistor). The current Champion replacement for these spark plug numbers is RJ12YC or RJ12Y. The "C" denotes a copper core electrode. Champion, and others, have consolidated heat ranges.

Some alternate brand crossover plugs include the following:
- Autolite 85 (or 75 non-resistor)
- NGK BP5S or BPR5S
- Accel 0437 or 0437S
- Denso W16PR-U or W16PRU
- Bosch W7FC
- AC R44S (or 44S, B44S non-resistor)

Mopar numbers for the original numbers are as follows:
- J11Y = 34P or 2642913
- RJ11Y = 34PR or 2642989
- RJ13Y = 35PR or 3438334

NOTE: RN12YC is a 3/4" reach plug used in many small block applications including LA318 and 360 engines. RJ12YC is a 3/8" reach plug used in big block wedge engines including 440 car engines.

Thanks guys. That is what I figured, didn't think it would be these. I will order the shorter reach plugs. Appreciate the item numbers.

 

[fakirone]

I had previously looked at the "Ignition" section, but found no specs. But, just now looked the "Specifications" sections, and lo and behold there it is. ‍

 

[Vaanth]

Tapered seats on a Chrysler B/RB motor? When and if did they change from the gasketed plug (J-13Y) to them?

Passenger car big block wedge engines (350, 361, 383, 400, 413, 426 wedge, and 440) all used 14mm, 3/8" reach, retracted (gasketed), 13/16" hex spark plugs. 361 and 413 heavy truck and industrial, and some marine engines used a 14mm, 3/4" reach, retracted (gasketed), 13/16" hex spark plug without a projected tip (example, Champion N6). Late 1970s 440-3 industrial/truck engines used a 14mm, .460" reach, tapered seat 5/8" hex spark plugs, originally OBL9Y, or substitute RBL9Y.

ACCEL used to make some "shorty" spark plugs for spcific Chrysler 440 motorhome applications. Same heat range, just shorter "outside" ceramics where the plug wires attached, for clearances in the tight "dog house" engine cover.

Accel still makes the short spark plug version of the J11Y/J12Y/J13Y which is #437S.

I use these on my 440 truck with headers due to pipe clearance issues with the stock plugs, and also with the Accel ceramic boot wires I have:

 

[Vaanth]

I remember that now.

I think they went to 2 books in 1971. Those were chassis and body. Somewhere along the way, they went to body and electrical. Maybe 1975?

The format of the service manual book(s) did vary over the years. For a loose snapshot of the 60s-80 centering on rear wheel drive cars:

Early 1960s had more specific model manuals:

1971 started the "Chassis" and "Body" manuals:

The three "brands" combined in 1975, and body wiring diagrams appeared in the "Body" manual:

In 1976, things switched to the "Body Chassis" and "Electrical" manuals:

In 1980, the manuals moved to "Body Chassis Electrical" and "Engine Performance" manuals:

In 1983 it became "Chassis & Body" and "Electrical & Engine Performance" manuals:

And in 1986, a single volume for rear wheel drive cars, which was growing few, and more and varied manuals for the other vehicles, particularly front which drive, which was growing more:

By the 2000s, things were becoming more electronic, but a print manual set for the 2008 300/Charger is five separate books:

 

[wyrmrider]

I'm not sure what the prior owner did, or why, but the long-reach LA motor plugs never have been installed in the B/RB motors at any time in their life. Maybe a bad auto supply parts person? Or a bad "guaranteed to fit, with modifications" eBay listing?

The saving grace might have been the .125" deck height of the 440 pistons at TDC? But that's still a big difference in the thread length.

Tapered seats on a Chrysler B/RB motor? When and if did they change from the gasketed plug (J-13Y) to them? "R" for resistor is not an issue in this.

Spark plugs have been listed in the "Specs" section of the "Ignition" section of the factory service manual, with the distributor advance specs and basic timing setting listings. "Tune Up" listings. In the pre-1966 FSMs, all of the specs were at the back of the manual, rather than in the section which they applied to.

@Big_John and @Vaanth are completely correct in the above comments as to spark plug usage.

Now, all of this is presuming that the stock-type cast iron cyl heads are still on the motor! Not some aftermarket aluminum cyl heads, which can use different-than-stock spark plugs.

ACCEL used to make some "shorty" spark plugs for spcific Chrysler 440 motorhome applications. Same heat range, just shorter "outside" ceramics where the plug wires attached, for clearances in the tight "dog house" engine cover.

Take care,n
CBODY67

not exactly 413 truck heads (with the valves canted like a FE ford) used 3/4 thread plugs
that said use the correct threads and gasket check and see of the heads have a flat face for gasketed plugs or tapered for the tapered no gasket plugs
then use one with the longest electrode into the chamber they idle and burn better (not for domed pistons or racing_