My2nd 69 442

I'm curious what spark plug you guys are using to replace the original AC/Delco R44S now that they are almost impossible to find.
I'll be installing in a 69 442 with a 400 BB

tru-blue 442

When I was driving my 69 442, I used R45S with the 400 G block.
I am running R44S in my 66 with the 400 E block. You have to hunt but
they are out there. You may try the Autolite 86. I have had good luck with those too.

oldcutlass

You can go one heat range hotter to an AC45S.

Junkman

I have been using Denso and NGK's for the last 15 years with great success in every one of my cars. The only reason for the two brands, is that sometimes I can get one brand quickly or it is in stock, and the other will take some time to come back into stock. I would say that the two brands are comparable. Had terrible luck with the AC's at high RPM.

Fun71

I have used Champion RJ12YC since the early 80s.

CRUZN 66

Are you looking to purchase some R44S plugs or just a substitute?

BangScreech4-4-2

If you want to go cooler, I believe they still make the R43S. With the salad oil that passes for gasoline today, this might be the way to go.

My2nd 69 442

I'm only looking to see what others are using. I currently have R45S installed but want to replace them as regular maintenance. No identified issues with what I have I only want to be prepared for a tune up.
Thanks for all replies.

oldcutlass

Everyone I know of that tried to go colder had fowling issues.

Hairy Olds

I tried NGK XR5s in my 67 442. They made a noticeable difference in performance and idle.

pogo69

look around for the r44s or r45s plugs they are still around and are factory plugs. That's what I have been using for 30 years with no complaints

My2nd 69 442

John, I would love to find a set(8) of the R44S plugs at a reasonable price. Do you know of a source?

BangScreech4-4-2

If those are working fine and you're not experiencing detonation, I'd tend to stick with them.

BangScreech4-4-2

And everybody who goes hotter (from R44S to R45S) seems to have to retard their timing.

oldcutlass

Where do you read this?

BangScreech4-4-2

Actually, I'm being facetious, although my own car did get a touch of detonation switching to the R45S which caused me to go to great lengths to find a set of R44S's. Conversely, I haven't heard of any major fouling episodes with the R43S, but would defer to your experience if you know otherwise.

CRUZN 66

I will check in my stock and see how many I have left and let you know...

BangScreech4-4-2

... which brings to mind the fact that R44S's ARE still available if you really want them -- just be prepared to pay a premium. If John can't help you, just check out E-Bay.

oldcutlass

I've seen this with very lean mixtures with the R45S.

Fun71

Back in the old days there were spark plug sandblasters to clean plugs so they could be reused (or continued to be used).

There's not much to a plug so if it is working now and the electrodes aren't eroded or the insulator isn't cracked, there shouldn't be any reason to replace it after a clean up.

oldcutlass

I still have one of those spark plug cleaners. I don't hardly use it any more, I clean mine with carb cleaner and a short brush, regap, and reinstall.

CRUZN 66

Sorry Jerry, all I have left are R45S & R46S, which I don't plan to sell at this time...

My2nd 69 442

For any interested, I found the R44S spark plugs on a web site autoplicity.com for 1.76 each. Their shipping is rather expensive, but at least their sales price is decent.
I'll update when I receive them.

BangScreech4-4-2

Good work. I'll remember this thread!

D. Yaros

The air powered sandblaster plug cleaner may still be purchased at places like J.C. Whitney, Northern Tool, Harbor Freight. I have/use one. Cannot remember from where I purchased it?

oldcutlass

Mine is a Craftsman, Sears still sells them for $28-35.

TripDeuces

I would caution against using any type of spark plug cleaner that 'sand blasts' the plug. They will remove all the sharp edges from the center electrode and ground strap. An electrical spark has a much easier time jumping a gap from a sharp edge to another sharp edge. When you round them off the secondary voltage has to get to a higher peak in order to jump that gap. That can wreck havoc with secondary ignition components.
This is the main reason for fine wire electrodes in most modern plugs as well as the use of platinum, it doesn't burn away as easily as plain steel and holds it's sharp edges better. Autolite plugs were known for having very hard electrodes and lasted the longest of the old school standard plugs.

Ozzie

I still have (and use) one of the old testers which also has optional cleaning ability. You really need a two stage compressor for it.

Ozzie

Replacement spark plugs for AC DELCO R44S:

Brand Model Accel 0437 Accel 138 Accel 437 Accel 437S Accel P437 Accel R44S Autolite 3224 Autolite 3225 Autolite 3226 Autolite 3227 Autolite 565 Autolite 84 Autolite 85 Beru 14R-11F Bosch WR10F Bosch WR8FC Bosch WR9FC Bosch stk 7516 Champion OJ11Y Champion OJ12Y Champion OJ13Y Champion RJ11J Champion RJ12Y Champion RJ12YC Champion RJ12YC6 Champion RJ13Y Champion RJ14J Champion RJ14Y Champion RJ14YC Champion stk 63 Denso 3037 Denso W14PR-U Denso W14PRU Denso W16PR-U Denso W16PRU Denso W20PR-U Denso stk 3037 Denso stk 5046 General Motors 5613866 Mighty M4R52 Mopar 2444870 Mopar 2642475 Mopar 3438334 Mopar 4091936 Motorcraft AR42 Motorcraft AR52 Motorcraft AS42C Motorcraft stk 49 Napa X701 NGK 2637 NGK 2990 NGK 7055 NGK BP5S NGK BPR4S NGK BPR4S-15 NGK BPR4S-20 NGK BPR5S NGK BPR5S-15 NGK R5670-6 NGK XR4 NGK XR40 NGK XR45 NGK XR5 NGK stk 2746 NGK stk 3332 Prestolite 14-32 Splitfire SM008E Torch G5TC Valley Forge 44R

oldcutlass

If you look at that list, a lot of those spark plugs are not direct replacements. They are 1 heat range higher or lower.

TripDeuces

Raising the heat range was common. I suppose it was a way to burn off deposits on the plug but that's just a guess.

Ozzie

Correct. The converter is a bit "liberal" providing some wiggle room. Establishing the exact operating temperatures is sometimes difficult. I suppose that the reader should keep this in mind when making a choice. Often some trial and error tests should be conducted.

tru-blue 442

I have some nos Delco R-47's. Pretty hot for higher compression engines though.

My2nd 69 442

Well Crap,
Autoplicity just now sent me a notice that my spark plug R44S order has been canceled with NO explanation as why.
I kinda sortta expected this, but it would be nice if an explanation had been offered and my money promptly refunded.
So if any of you have a source for these spark plugs, I will be thankful for a heads up. Per the chart on reading spark plug condition, I believe my plugs (R45S) may a range to hot.
Thanks for all the replies

tru-blue 442

Jerry, if you can find some R45's they will be fine. Worst case, you may have
to retard the ignition a little if you experience pinging.

rcorrigan5

I have R45S plugs in both my '68 and '69 4-4-2 convertibles. The engines are pretty much stock, no upgrades, just rebuilt 30 thousandths over for both. The '68 has a Pertronix set-up and the '69 has points and condenser because I didn't notice any performance difference in the '68 when I switched over to Pertonix from points and condenser. And from a performance standard, I didn't notice any difference in going from the R44S to the R45S. But I don't race or push these cars hard at all, either. Both are just Sunday drivers.

Randy C.

My2nd 69 442

The only possible issue that I personally have with the R45S plugs is that my plugs show almost totally white on removal and my exhaust tips are coal black plus the fact that my gas mileage is terrible at 6.9 MPG. I fully understand that the mileage is not going to improve with a simple plug change. I just want to try to cover all bases when I get around to rebuilding the carb and possibly going to a smaller main jet. I'm open to most all suggestions on how to improve mileage and still get good performance.
Thanks for all the replies thus far

oldcutlass

Its hard to judge plugs with ethanol fuel unless there is just something blatantly wrong. The black on your tailpipe is probably more due to short trips and not getting the exhaust hot enough. Again with ethanol fuel we don't get that chalking effect that we used to get in days of old.

jpc647

I have r45's in my 72 cutlass, 350 with HEI and I have not had to retard the timing at all. Mine are gapped at .040. I've been increasing the timing trying to get a little bit more out of the car lately, and no pinging. On regular 87 octane fuel too.

I was thinking, I might even try to go up a heat range, or try some of the ngk plugs with the dual or triangle tips.

tru-blue 442

jpc, is your 350 stock? If so, low compression engine, but easier to jump a heat
range or two I would think. Here's a fun pic for comparisons guys.
From left to right...R43-R44SX-R44S-R45S-R46SX-R47