Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Classic Parts
American Auto Wire Classic Industries
Danchuk Catalog
Hellwig Products IncPerformance Rod & CustomNu-Relics Power Windows





Username Post: original spark plugs        (Topic#337156)
bowtiefan 
"12th Year" Gold Supporting Member
Posts: 2303
bowtiefan
Loc: Vacaville, CA
Reg: 02-19-04
07-02-16 06:45 PM - Post#2637387    

I am getting our '70 RS with a 307 ready for the VCCA show in Tahoe next month. I am trying to find some spark plugs. From what I can gather, the stock plugs were AC R44. I can find lots of R44's but they all have a suffix, such as XLS, LTS, XL, SX, T, N etc. but no straight R44's. I don't know what the suffixes mean, so what will work in our 307? I need ones with the green stripes.
Thanks
Ken

36, 38 & 39 2dr sedan, 41 coupe, 54 convertible, 56 Nomad, 57 210 2dr sdn, 70 Camaro RS, Corvettes; 57, 61, 65 396 coupe, 67 427 convert, 72 T-top, 88 coupe,91 ZR-1, 07 Z06, 16 Z06, 07 Silverado, 09 BMW 135i vert.


Edited by bowtiefan on 07-02-16 06:51 PM. Reason for edit: No reason given.

 




raycow 
DECEASED
Posts: 27999
raycow
Loc: San Francisco, CA
Reg: 11-26-02
07-02-16 08:29 PM - Post#2637400    
    In response to bowtiefan

I don't believe a plain R44 would have been factory installed in a car as new as yours. This was a washer seat plug that has the center electrode flush with the end of the threaded shell. It was replaced by R44S for OHV engines sometime in the late 50s or early 60s. The "S" means extended tip.

The suffix describes thread length, taper or washer seat, and electrode protrusion. You will probably want either R44S or R44TS, depending on whether your heads have washer seats or taper seats. According to this, Chevy changed to taper seats in 71.
https://www.chevytalk.org/fusionbb/showtopic.php?ti...

You could look here and see which one matches what you have in there now.
http://www.rockauto.com/en/partsearch/?mfr=AC DELCO...

However, I have seen engines with incorrect plugs in them and they still ran, at least for a while anyway. The smart thing to do would be to look at the heads, not the plugs. You will be able to see if they are taper seat or not.

Ray

Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive.


 
bowtiefan 
"12th Year" Gold Supporting Member
Posts: 2303
bowtiefan
Loc: Vacaville, CA
Reg: 02-19-04
07-04-16 07:51 AM - Post#2637700    
    In response to raycow

Ray, the owners manual calls for R44, so I am kind of confused. To be correct, they also need the green rings, I just need to find the correct plugs. There are a couple sets of R44 on ebay, one for $70 and one for $100, so I am kind of looking for something similar that isn't quite so pricey. So would I want the R44S? What does the S or TS mean, or should I say, what is the difference?
Ken

36, 38 & 39 2dr sedan, 41 coupe, 54 convertible, 56 Nomad, 57 210 2dr sdn, 70 Camaro RS, Corvettes; 57, 61, 65 396 coupe, 67 427 convert, 72 T-top, 88 coupe,91 ZR-1, 07 Z06, 16 Z06, 07 Silverado, 09 BMW 135i vert.


 
raycow 
DECEASED
Posts: 27999
raycow
Loc: San Francisco, CA
Reg: 11-26-02
07-04-16 11:29 AM - Post#2637728    
    In response to bowtiefan

The "T" is easy. It means tapered seat. Tapered seat plugs seal on the taper and don't use a washer. This one is a no-brainer. Take out a plug and look at the seat in the head. Either it has a tapered seat or it doesn't.

The "S" means extended tip. You can see what that looks like on the Rockauto page I linked. A plug without the extended tip will have the center electrode approximately flush with the end of the shell. "S" plugs were developed to give better performance in OHV engines, but aren't advised in flatheads, as the side electrode might contact a valve when it opens. I use "S" plugs in all of my (stock) engines and I have never had a plug contact a piston, but I suppose anything might be possible with aftermarket domed pistons.

To be honest, I really don't know why GM spec'd a non-"S" plug for your engine. If you are doing a stock resto for show points, keep on looking for the R44. You never know when you might find a fussy judge who will pull off a plug boot just to see the legend on the insulator. Otherwise, this might be a good question to ask on the performance forum.

"TS" means tapered seat AND extended tip.

Ray

Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive.


 
bowtiefan 
"12th Year" Gold Supporting Member
Posts: 2303
bowtiefan
Loc: Vacaville, CA
Reg: 02-19-04
07-04-16 12:07 PM - Post#2637734    
    In response to raycow

Thanks Ray, that helps a lot. Are you going to the VCCA meet in Tahoe in Aug.? If so, I'd like to meet you.
Ken

36, 38 & 39 2dr sedan, 41 coupe, 54 convertible, 56 Nomad, 57 210 2dr sdn, 70 Camaro RS, Corvettes; 57, 61, 65 396 coupe, 67 427 convert, 72 T-top, 88 coupe,91 ZR-1, 07 Z06, 16 Z06, 07 Silverado, 09 BMW 135i vert.


 
raycow 
DECEASED
Posts: 27999
raycow
Loc: San Francisco, CA
Reg: 11-26-02
07-05-16 01:56 PM - Post#2637959    
    In response to bowtiefan

Ken, thank you for the invitation. I would look forward to meeting you and your cars, too.

Unfortunately, I won't be able to make it to Tahoe. However, I do visit every SAC now and then, so it would be no problem to stop off at Vacaville on the way. I'll send you a PM and let you know the next time I have a trip planned.

Ray

Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive.


 
pauldian 
Contributor
Posts: 286
pauldian
Loc: seligman,arizona
Reg: 05-14-09
07-07-16 07:17 PM - Post#2638413    
    In response to raycow

Ken, if memory serves me right? The plug for the 1970 R.S. came from the factory with AC44 which are not made any more. These were replaced with the R44.




 




Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

1630 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.165 seconds.   Total Queries: 16   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 12:02 AM
Top