Autolite 225 spark plugs?

[fwi]

I have those plugs in my stock 383, pulled them yesterday, looks like its running very rich as they were all black, but are these the right plugs for that engine to begin with?

 

[idrivemopar]

I see either j14y or j11y listed for 383 plugs, which cross reference to Autolite 85 or 86. Not sure why there are two types listed for 383, must be something to do with 2 barrel versus 4 barrel versions.

 

[kiwigtx]

Not sure why there are two types listed for 383, must be something to do with 2 barrel versus 4 barrel versions.

Might be two listings to cover different grades of fuel.

 

[oldbee]

In '68 the j-11's were for 383-4bbl. J-14's for 2bbl. Different carbs,cams,exhaust,timing,etc.

 

[RJRENTON]

Gentlemen,
Autolite makes very good plugs and are reasonably priced. However they have a VERY CRYPTIC heat range chart...difficult to figure out which plugs are hotter/colder.
For my money i prefer Champion or NGK or even AC. Their heat range charts are easy to figure out which is hotter/colder for a given design and type.
Champion plugs are available on the internet/eBay. NGK plugs offers many different styles, electode alloys, and are reasonably priced.
Spark plugs (hoter/colder) are determined by several engine variables: reach, compression ratio, spark advance characteristics (rate of advance, static timing, total advance), intended service for the engine, and of course fuel mixture and distribution.
NGK offers an excellent explanation of heat range and the plug's operating temperatures (fouling & preignition) extremes. I suggest you read the write up...very helpful.
Any questions, PM me if you want.
Bob Renton

 

[PurpleBeeper]

I have those plugs in my stock 383, pulled them yesterday, looks like its running very rich as they were all black, but are these the right plugs for that engine to begin with?

My suggestion would be to put whatever Champion plug cam originally in that stock 383 of yours and see if they get "sooty" too, then check your carburetor (and air filter) if they do. If they look rich, the engine is probably rich unless the plugs are much colder than the stock Champions in my opinion. There are other more advanced tuners here on this site that can help too.

 

[miller]

I see either j14y or j11y listed for 383 plugs

I'd shove Champion j12y in it, and be done. Can't find j11y these days, the 12s replace them.
Depends on your ignition, for which j12y you want. Rj12y are for resistor/electronic type, or rj12yc (c=copper core). Standard point ignition...j12y.

 

[fwi]

I still have the hot MSD AL2 from its previous racing life.

 

[oldbee]

Ign. box doesn't really matter.

 

[RJRENTON]

I'd shove Champion j12y in it, and be done. Can't find j11y these days, the 12s replace them.
Depends on your ignition, for which j12y you want. Rj12y are for resistor/electronic type, or rj12yc (c=copper core). Standard point ignition...j12y.

Champion J11Y's (Mopar P34P) are still available.....you just have to kook for them....I purchased 15 sets of NOS Mopar P34P plugs on the internet (eBay) from a guy in Texas for <$8.00 / set. Champion J12Y, or RJ12y or J12YC, will work just fine. You could use J13Y or Mopar P35P as alternates. Autolite AP85 are platinum tip plugs available just about any auto part store for $2.50 each. As the old '49ers use to say: gold is where you find it.
Bob Renton