defiant1

Since they don't make a AC Delco R46s spark plug anymore, what is a suitable substitute?

d1

1969w3155

AC SPARK PLUG (8) spark plugs R46S GM 5613879
AC SPARK PLUG (8) spark plugs R46S GM 5613879

AC SPARK PLUG (8) spark plugs R46S GM 5613879

Heres some on ebay. I believe Fusicks' suggests R45S, and they have R46S NOS.

defiant1

Thanks for links. I was basing my experience off of my local parts stores. They would run the part # and would determine the spark plugs as "Not Listed" part and recommeded the R45S as well.

Blk71SX

they're not listed because they are no longer produced. the R46's were used when 45's were fouling. AC also dropped the R46TS's

btw, the ebay plugs are GONE

defiant1

Do you have any recommendations for a similar 46S style plug?

69Rman

Here's some more on Epay...
Hopefully not the same ones as earlier on in the post...
http://cgi.ebay.ca/8-ACDelco-SPARK-P...item4a8cab9f71
Duane

1969w3155

Try Autolite "86"

Blk71SX

86's are also shown to replace a 45, seems to be a catch all.

most likely R45S's will serve the OP well. at least untill some 46's are obtained.

by my experience with Autolite plugs they would be my second choice after ACs

1969w3155

They seem to be eliminating more and more parts, and replacing with a "one for all" mentality, been seeing that with the AC oil filters as well, same part number but the size of the filter has changed.

ddd777

There seem to be plenty of R46S plugs available on ebay.

They all look fresh, but plenty old.

Do any of the materials in a spark plug degrade with age?

Is it really worth paying any sort of premium - or should one just get the modern R45S and call it a day?

MDchanic

Not if you're talking the age of our cars.

If you're talking geologic age, that's a different story.


It's a question of which temperature range works best for you.
If the R45s don't foul, there's no need for a hotter plug.
If the R45s do foul, then you need the R46s.

- Eric

oldcutlass

Or you can go one heat range higher. They quit making the 46's a while back.

ddd777

According to this PDF the heat ranges are:
0-1-2-3-4-5-6-7-8-9
Cold ———— Hot

But of course there is no list of products....as 46 would be the next logical hotter plug...sigh.

http://www.archivedsites.com/TECH_CO...c%2007%20F.pdf

mpolds

The most suitable current plug is R45S, 1/2 heat range cooler....

I have some 46S (Non-resistor) and some R46S (Resistor) N.O.S. A C --
not many of each remaining....

I don't need the mega - bucks that some people ask for N.O.S. spark plugs.

Call me -- Craig -- 516 - 485 - 1935 ..... New York....

Run to Rund

Autolite 85 seems to be a good all-around plug.