[fyrffytr1]

On A/C Delco R43s plugs which way does the crush washer go? One side of it is wider that the other. Or, does it even matter?

[Singleton]

wide side to plug is the way I have always seen them

[fyrffytr1]

OK. I went to the A/C Delco site and found this picture. It shows wide side away from the plug.

[Singleton]

Guess my memory isn't what it used to be. Been awhile since I've used that type, I have 6x heads that use tapers

[fyrffytr1]

You still beat me. I have 670 heads and didn't know which way they go! Some of the old plugs had them one way and the others were the reverse!

[Old Goat 67]

Think about it. AC knew their plugs were flat, they had no idea what shape the heads were in.

[GT182]

Why 43S plugs? They're supposed to be 45S.

Doesn't matter which way the washer is, just as long as you use it. Everyone I've watched install them, including me, just puts the washer on and installs them..... if they fell of in the package.

[Jerry H.]

Originally Posted by GT182

Why 43S plugs? They're supposed to be 45S.

Doesn't matter which way the washer is, just as long as you use it. Everyone I've watched install them, including me, just puts the washer on and installs them..... if they fell of in the package.

x2

I've probably installed 100 sets of these plugs over the years and I've never paid any attention to which way the washer went. Never had any problem with any of them either.

[fyrffytr1]

Gary,
I went with the 43s because that is what a 67 calls for. At least that is what the computer at work lists for it. Remember, I have a 69 block with 67 670 heads and a 71 intake and carb.
Is there a reason I should go with the 45s? I haven't put the 43s in yet so it is no problem to exchange them.
I just went to another auto parts site and they list both the 43s and the 45s as OEM. I wonder why the parts place I work for only lists the 43s?

[GT182]

I'll check my 70 Chiltons book in the morning and get back to you.

[Karl Shoemaker]

I've never read or seen anything about how to put on the crush rings or have I ever heard of anything bad or good about the affects of which way they were installed as long as long as you use them on plugs that require them. I'm sure there was a reason for they're design. It might simply be to allow the larger flexible part of the ring to close in around the smaller to get a better seal unlike the solid flat brass washers used on earlier plugs?
As far as the AC 43S in a 67 GTO, my 1967 AC Dealer's Catalog lists all 67 GTOs and 428s to use AC 44S all NON-GTO 400s and 326s to use AC 45S. My 1976 AC Dealers' Catalog lists all plugs to go up one in temp ratings[67 GTO R45S] probably because of the different gasoline being used? Todays gasolines are not the gas your car originally ran on. All my AC DELCO catalogs from 1971 up call for AC R45S plugs in 67 GTOs and R46S in other Pontiac V-8s or GTOs that are used more for easy driving.
Most manufactorers, including AC DELCO, [I think NGK is opposite] use the lower the #[43S], the colder the plug. Hotter plugs[46S] are recomended for around town ect. and will not foul as easily from oil, gasoline aditives, ect. but can cause pre-ignition. If left pinging, can burn through your pistons. Colder plugs will tend to foul easier around town, cause loss of power, emmissions issues, you'll do a lot more plug changing, but are better for highway and hard driving. My friend that used to race, would warm his engine up with AC 46S, once hot, he would switch to the AC 42S for racing.
The R45S is probably the best general purpose plug for todays driving. A resistor to lower static in your radio and those around you, won't easily foul, and still gives needed power for occational hard street driving.
IF you want to to totally 100% show correct, I believe 67 GTOs were issued with AC 44S. If it's not going to be a trailer queen and you plan on using it, cruisin', ect., I would use the R45S. IF your foot gets heavy a lot but mostly cruise, I might go to the R44S.
This is all my personal experience and oppinion and that's all.
Hope this helps some?

[fyrffytr1]

Karl,
Thanks for the information. I drive my car once or twice a week mostly around town but I do take it out on the expressway at least once a week and run it at speed. I use non-ethanol gas but can only get it in 87 octane. And, I have been guilty of getting in it but not a lot. I think I will go with the R45S.

[GT182]

Two questions Phil. Is your GTO set up for real Ram Air and what is the horsepower? If no Ram Air I should think only the heads come into play, and take a guess on the horsepower for yours.

Now my findings from by my 73 Chilton's Manual [for 600 to 73] listings for 67 heads is...
R-46S for 265hp
R-45S for 335hp
R-44S for 360hp
R-44S for 360 Ram Air
Reference: All plugs gapped at .35 for 66 to 72. .40 gap for 73 engines.
I've used this manual for all my 66 Pontiacs I had over the years. All the really good mechanics I knew back then said no problem with what Chilton said to use and do. A few even used the same manual, others used the Motor's Manual.

There's no mention of 43S plugs anywhere from 66 up to and including 1973. So how where you work came up with them is beyond me. Additional info.... R-47S plugs are in the mix for a 71 350 250hp and 71 400 265hp engines.

Note: I'm running a stock Pontiac HEI distributor and a 650cfm Carter AFB Competition Series 4bbl.
For my 68 XX low compression 400 400hp I'm using the R-45S plugs gapped at .35. Runs fine no matter what gas I use.... E10 87 octane, E10 Super, 100LL, 110 no lead racing gas. Never had any knock or pre-ignition with any of the gas grades I've used.

[fyrffytr1]

Gary,
No ram air set-up. I have no idea on horsepower except that it has all I want. I do not know anything about the internals as I have never had the motor apart. It was running good when I got the car and had been rebuilt sometime in the 10 years before I bought it. Now, I know 10 years sounds like a long time but the car was never on the road. The previous owner said that he would go out about once a month to start it and let it run for awhile but he never drove it.
I would like to put a hydraulic roller cam in it but that is down the road.There is a car show coming up in a month and sometimes they have a dyno machine set up. If it is there I may put mine on it to see what HP and torque I get to play with.
I will return the 43s tomorrow and get a set of 45s.

[GT182]

Good choice Phil. To me the 45S plugs are a good all around plug to use.

I can't understand why where you work they'd say to use R-43S plugs. : Personally I've never seen them used for any Pontiac engine. Tho maybe someone else has.

[fyrffytr1]

Gary,
Maybe it's because the OEM was a 44s and we do not carry the R44S. So they chose the R43S as a substitute. Go to any parts store website and see what they call for. I forgot the 43s this morning so I will swap them out tomorrow but I won't get them installed because I have to have my taxes filled out tomorrow evening.

[GT182]

Usually the 45S is what's called for. I checked at the parts store I go to to see what they recommend and it was the 45s. I bought 2 sets of 45s and have one set already to install as soon as it warms up.

[fyrffytr1]

I swapped my plugs out today and will get them installed sometime before spring......I hope!

[geeteeohguy]

43s is a cooler running plug than a 45s. If your car doesn't foul out the 43 plugs, no worries. A 45 plug will run hotter and was designed for lower compression, lower performance engines than the stock 44s plug specified. Me, I'd run 43 plugs over 45 plugs if I didn't get any fouling. Less inclined to detonate with a cooler plug.

[SD421]

Originally Posted by geeteeohguy

43s is a cooler running plug than a 45s. If your car doesn't foul out the 43 plugs, no worries. A 45 plug will run hotter and was designed for lower compression, lower performance engines than the stock 44s plug specified. Me, I'd run 43 plugs over 45 plugs if I didn't get any fouling. Less inclined to detonate with a cooler plug.

Jeff,
Do you think it would help if I changed from 45S to a 44S to help with my engine's 3,000 Rpm cruising speed? Help with engine cooling?
Don