Advice on spark plugs

[Mopewbie]

Hi all, I would like some advice on spark plugs. A is from a 440 6 pack, is that too rich?
And B is from a 318 4 barrel, is that too lean?

Thank you a lot.

 

[Mopewbie]

440

 

[493 Mike]

Send us the plug numbers and approximate milage on each.
Mike

 

[Mopewbie]

Send us the plug numbers and approximate milage on each.
Mike

A ones are NGK B6S (being replaced for AC Delco R43S)
B are Champion RN14YC (being replaced for Champion 3405)

No idea about mileage, got the car with them and just checking it now.

 

[493 Mike]

I think you should replace them and then check the new plugs after driving. Then you will have an idea of how the engines perform. I imagine the engines were started multiple times without warming up which will lead to extra deposits on the plugs.
Mike

 

[RJRENTON]

A ones are NGK B6S (being replaced for AC Delco R43S)
B are Champion RN14YC (being replaced for Champion 3405)

No idea about mileage, got the car with them and just checking it now.

Personally, i would use AC/DELCO R44S as its one step hotter.....or consider Champion RJ-12YC or Autolite AP85. The origional NGKs shown as just a little too cold. Origional plugs were Mopar P34P equal to Champion J11Y. The current venue of plugs have a copper component in their center electrode which results in a broader heat range. But mixture, spark advance characteristics, cam shaft and compression ratio all influence the spark plug coloration. Just my opinion of course.
BOB RENTON

 

[Mopewbie]

Personally, i would use AC/DELCO R44S as its one step hotter.....or consider Champion RJ-12YC or Autolite AP85. The origional NGKs shown as just a little too cold. Origional plugs were Mopar P34P equal to Champion J11Y. The current venue of plugs have a copper component in their center electrode which results in a broader heat range. But mixture, spark advance characteristics, cam shaft and compression ratio all influence the spark plug coloration. Just my opinion of course.
BOB RENTON

Thanks. Thats for the 440 I presume?

I was going with NGK 7355 (Iridium) but decided not to last minute. Not sure if it makes a huge difference or not anyway.

 

[Frank Mopar]

https://www.championautoparts.com/P...air-and-maintenance/Spark-Plug-Materials.html

 

[Master Gunner]

Don't know why you had the the B6S plugs in the 440, not even recommended for a stock 6bbl or any 440. The stock plug would be a GR4 or a BPR4ES. Without any info on compression, cam, ignition, exhaust, it's hard to say what would work, I use NGK R5670-6 with my setup with very good results.
As far as the 318 plugs go, was it a factory 4bbl, or was it added, and what year is the basic engine? Need more info on that one.
I would also use NGK plugs before AC's, but that's just been my experience, and everybody has their favorites, just like politics.

Mark

 

[RJRENTON]

The "BEST" spark plug as stated is a matter of personal choice, sometimes based strictly on conjecture, perception, or actual testing that yields definitive results.....lower ETs, better fuel milage, etc. Over yhe years, I found that for my application, the engine seems to like: Champion UJ11G or Champion HO8A, both are precious metal center electrode moderate heat range and NON projected nose plugs. I doubt these are available readily; i find them on the internet and eBay.
Spark plugs are like oil, anti-freeze, axle bearings ("Green" vs Timken), wax, beer, pizza and steak.....everyone has their idea of the "best".....right or wrong, good or bad .....
BOB RENTON

 

[451Mopar]

Both look like there is alot of miles on them.
Usually want to check the plugs after some highway driving or a hard pass down the track.
If the engine was idling and low speed stop and go driving, it makes reading the plugs really hard unless you know more about the tune up.
"A" is so rich and carboned up. I think the air/fuel ratio needs to be fixed (leaned out). The plug heat range is harder to see on the threads of the short threaded plugs, Might need a hotter plug, but hard to tell until the air/fuel mixture is fixed. A hotter plug would help burn some of the carbon off if the engine is still running rich (or burning some oil?)
"B" looks pretty decent heat range and timing wise. The carbon around the ring could be mileage or just too much slow driving before pulling the plugs?

 

[Ron H]

I’d be inclined to run some engine cleaner as well in the oil and gas. Seems like a good amount of carbon build up or could be those plugs have been in for eons. Change the oil after a few hundred miles after running the cleaner. Also do a timing check on those motors…could be you’ve got this in mind; but thought I’d toss it in for my 2 pennies. I had carbon build up on a couple of valves before I rebuilt my poly and got improvement running some marvel oil and seafoam.

 

[Mopewbie]

https://www.championautoparts.com/P...air-and-maintenance/Spark-Plug-Materials.html

Thank you, very informative.

Don't know why you had the the B6S plugs in the 440, not even recommended for a stock 6bbl or any 440. The stock plug would be a GR4 or a BPR4ES. Without any info on compression, cam, ignition, exhaust, it's hard to say what would work, I use NGK R5670-6 with my setup with very good results.
As far as the 318 plugs go, was it a factory 4bbl, or was it added, and what year is the basic engine? Need more info on that one.
I would also use NGK plugs before AC's, but that's just been my experience, and everybody has their favorites, just like politics.

Mark

Thanks all for the answers. It's very satisfying to be able to ask anything from silly to highly technical in this forum and always learn somehing.

No idea why the B6S, I was surprised as well.
The 318 was originally 2bbl, someone installed a holley 4bbl at some point probably many many years ago. Engine 73.

 

[Master Gunner]

1973 318 used a Champion RN14YC or NGK GR4. The 340 used the same plug, so it seems the 4bbl doesn't change anything.
Something of note though, the Parts Watch program we use is incorrect for a 1970 V code 440 and gives the small block plug as the factory plug. The actual plug would be a Champion RJ12YC or NGK XR5.
Sorry about the bad intel, but in my defense it was a mistake in the parts program, I'm just happy I found it before I got crucified for giving bad info.

Mark

 

[RJRENTON]

1973 318 used a Champion RN14YC or NGK GR4. The 340 used the same plug, so it seems the 4bbl doesn't change anything.
Something of note though, the Parts Watch program we use is incorrect for a 1970 V code 440 and gives the small block plug as the factory plug. The actual plug would be a Champion RJ12YC or NGK XR5.
Sorry about the bad intel, but in my defense it was a mistake in the parts program, I'm just happy I found it before I got crucified for giving bad info.

Mark

The origional LA 318 (1967) engine used Champion N14Y. Later variations, as emission control requirements became more stringent, and as spark plug designs improved, with the advent of the inclusion of copper alloy in the center electrode, heat ranges became broader for the same part number plug. When EGR was introduced, 1973 vintage, combustion chamber temps dropped so a hotter (usually) plug was required.
The first year LA 340 engine (1968) compression ratio was 10.5:1, spark advance characteristics was quick, cam promoted higher top end operation and the origional plugs were Champion N9Y. The same year Hemi came with Champion N10Y, which proved to be too cold for the average use person. Dealers retrofitted with Champion N12Y to reduce cold fouling. Resistor designation ("R") were adopted about the time catalytic converters were added to promote longer plug life and RFI reduction.
For my old '67 Belevedere II with the first generation LA 318 after fitting with a 4 bbl carb, and cam, etc., i switched to Champion N11Y plugs along with a faster distributor advance curve. Just a few additional talking points.
BOB RENTON

 

[70bigblockdodge]

A there is nothing to read except it has been in there a long time.
B, is actually pretty good. Heat band on the ground strap is in the bend so it is good, has plenty of miles and could probably pick up a little with a primary side jet increase.