Packard Forum Index » V-8 (1955-56)

55 and 56 -- all models. As I said, for what it's worth.

Ok, I've read through this Post but would like to get some confirmation on what I saw.

I'm looking to get new plugs for my LATE 1955 Patrician(VIN 10027).

I've pulled the current plugs and they are Champion H14Y. The gap looks ok(not smashed).

Should I replace with New Champion H14Y? (H10 originally)

Or should I go with Champion N16YC? (N18 originally)


Thanks.

I use Autolite 65 with complete satisfaction.

The N-18 (N18), which has a 3/4" reach, was originally specified for ALL 56th Series models.

The H-10 (H10), which has a 7/16" reach, was originally specified for ALL 55th Series models.

However, there is an exception that involves ONLY 1955 Clipper Deluxe and Super models - a running change in cylinder head design for the 320-cid V8, which was covered in SC Vol. 29, No. 7 (duly noted in this site's EXCLUSIVE Packard Service Index). Spark plug supplier catalogs seem to be ignorant of details regarding this change.

Meanwhile, Kanter's staff advised me, about 25 years ago, that H14Y was the replacement for the H10. However, I found H10s readily available at the local parts store, back then - allegedly used in agricultural applications. I can't speak to present availability of any spark plug, today.

Also, DO NOT use a LONG reach plug in an application that specifies a short reach plug.

I bought h10 on eBay for a poop load of money back 8 months ago or so. But I wanted original. They were still in the wrappers.

My head hurts. I've read and re-read the posts. Tomorrow after the new carb is installed, the 400 will be tuned if necessary.
I think I understand my spark plug options are AC45 LS, AL 437 or NAPA (Champion) 857's. All gapped at .035 inches.

In ancient Champion speak: J series = 3/8" reach; H series = 7/16" reach; and N series = 3/4" reach. Each series had a range of heat ranges. Also, each series was offered in projected electrode ("Y" designated) and standard electrode; resistor ("R" designated) and non-resistor; and copper core ("C" designated) or standard core.

(o[]o)

Thanks JW. I found the letter designations helpful to me. BTW, O'Rielly's has the 437's. Going to pick them up now and then onto Auto Zone for points.

RE: picture. I found these orphans on a shelf in the garage. Per OD's chart, the 43Ls's look to be too cold and the AL 7's a bit warmer than necessary. Back to the shelf they go!

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or on ebay since you wont need them. ;0) then you can use the shelf space for a backup set of correct spark plugs. ;0)

Kevin,

Just make sure you get the correct reach plugs (in addition to the right heat range). Brand be damned.

You will ruin a motor if 3/4" reach plugs are installed in an engine designed for 7/16" reach plugs. 7/16" reach plugs will go into a 3/4" spark plug hole and work, but the bottom threads of the spark plug hole exposed to combustion will carbon up and you will not be able to install the correct 3/4" plugs the next time.

So, a 7/16" plug can go into a 3/4" hole, but a 3/4" plug cannot go into a 7/16" hole. Good night...

(o[]o)