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AC Delco spark plugs for Riviera 401


rodneybeauchamp

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Can any one offer advice as to correct AC Delco spark plug for 63 Riviera with 401. Shop manual states AC44S and what came out were R44S (resistor series plugs).

 

However my supplier has given me R43S which the AC online catalogue suggests. According to what I can tell from the numbering system, this will be a next step colder plug than what Buick recommended. 

 

Can anyone confirm what is the correct AC plug for this Riviera?

 

BTW how does one change the one under the air conditioning compressor without moving everything??

 

thanks

Rodney

 

 

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TS stands for tapered seat. I am pretty sure mine are all flat bottom, gasketed plugs. And I have been using a 45 heat range for decades. I used to have a big bag of sooty 44's in a cabinet if I haven't tossed them. Those ran too cool for me.

 

A few years ago I started using NGK plugs. I haven't put a set in a 401/425 engine yet so I don't know the number. I got into them on a recommendation for Jaguar V12's. I figured it they would run in that engine they were worth a try. I did a tune up on a '50 Super and tossed the old AC45 on the counter and told them to match it. They were great.

I have them in my '86 3.8, as well. I imagine I will eventually use them in all the cars.

Being in Australia, it is probably a good option to explore.

Bernie

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Hi Rodney,

I use R43S plugs in my '63 with fine results. Electrodes are nice and beige-y upon routine inspection on an original Nailhead 401 that has gone once around the clock. I should add that I have a 'Pertronix Ignitor II' electronic ignition system (they should name a drink after that!) with a Pertronix 40K volt coil and the black stock-looking Pertronix plug wires. All the difference in the world, IMO.

    

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Hi run delco R45S plugs.  They are one step hotter than original and work perfect.  I prefer a slightly hotter plug than a colder one, just because 90% of the Nailhead left do not have the compression they used too. Hotter plug helps keep it running clean.  Do NOT use another brand than delco, the threads are not long enough and the eltrode will be recessed in the hole. I have built almost 20 nailhads and they all run delco 45's except one is high compression motor I built.  

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Thanks for all that info, going to try the R43S because I have them. We live in a country town so lots of places are on roads with 100km speed limit, certainly not bumper to bumper. Then if no joy might look at 45s or even NGK equivalent to the 44s.

 

many thanks

Rodney

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I just looked at Encounter Bay. Google Brockport, New York and back out three clicks. Same deal, a big body of water and only three main roads. I can only go 7 miles to the north. Gets boring with only three points on the compass.

Bernie

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Bernie,

it looks a lovely place, why do you need a car?

 

If I lived there I would be walking every where. Very scenic from the photos along the river, the lift bridge etc.

 

We are a little bit lucky here, we only need to travel 80kms before we hit real traffic. Except in the holiday season, when it gets a little busy. Locals complain because they can't get a park right outside the Post Office like they always do during the year. Being a seaside holiday town, it is very seasonal, like in winter, some say you can shoot a gun down the Main Street, not hit a thing.

 

enjoy

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  • 4 months later...

I have a question to you folks regarding the correct spark plug selection.

I remember it was discussed here in an other topic, but I did not find in in my search.

As the old AC telco plugs are hard to find in Europe and 2 of 8 plugs ordered in oversea were defect, I've decided to replace them by a simple to purchase EU choice.

I found machting  NSK spark plugs ( cross reference table)  but they are without the "R" for Resistor.  I'm using the same plugs in my 66 chrysler, but it has installed a blast resistor in the ignition system. 

Do I need to install a ballast resistor into the Rivera, when using 44S instead of R44S or any other brand spark plug without resistor ?

 

I want to avoid damaging my engine over time by using a wrong spark plug. It rans now 200 miles with the new NSK and the color of the plug looks very good.

 

Thanks for you help,

 

Frank

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48 minutes ago, OldGerman said:

I have a question to you folks regarding the correct spark plug selection.

I remember it was discussed here in an other topic, but I did not find in in my search.

As the old AC telco plugs are hard to find in Europe and 2 of 8 plugs ordered in oversea were defect, I've decided to replace them by a simple to purchase EU choice.

I found machting  NSK spark plugs ( cross reference table)  but they are without the "R" for Resistor.  I'm using the same plugs in my 66 chrysler, but it has installed a blast resistor in the ignition system. 

Do I need to install a ballast resistor into the Rivera, when using 44S instead of R44S or any other brand spark plug without resistor ?

 

I want to avoid damaging my engine over time by using a wrong spark plug. It rans now 200 miles with the new NSK and the color of the plug looks very good.

 

Thanks for you help,

 

Frank

 

Frank-

The "resistor" built into a spark plug is there to reduce engine ignition noise on the radio.  It was not used on the original Riviera spark plugs.  It is optional.

 

The resistor in the spark plugs has nothing to do with the "ballast resistor" that the ignition system uses.  Buick has the resistor built into the wiring harness.  You have it, you just can't see it.  Chrysler (and Ford) chose to have their ballast resistor out in the open where you can see it and change it if you want to.

 

You will not damage your engine by using a plug with no resistor built into it.

 

The biggest risk you run to harming your engine is running too hot of a plug and having the engine "ping" when you accelerate quickly (try to get a lot of power out of the engine).  On a hot engine, with high compression, perhaps with the fuel octane number not as high today as it was in 1963-66, you can get this pinging.  A cooler plug, like the 43S, will help avoid this.  A hotter plug, like the 45S can make it worse.  So listen for that and change to a cooler plug (and also perhaps reduce some of your spark advance) if you hear it.

 

 

 

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