RC 15 radiator cap question

[Barbara S.]

Before I ask my question about the AC radiator cap that came with my '67 coupe, I have read the article written by Patrick Hulst and Tony Hurtado in the Winter, 2006 issue of CR. That article didn't squarely answer my question since it mentions anomolies in the production caps, but showed no photos of such caps.

First, my car is a very late '67 model small block car. It was built in mid-June, 67. The cap has the familiar AC in a circle at 9:00 o'clock. At 3:00 o'clock, and contained within a circle are: 15 LB and below it reads RC 15. At the top of the cap, it reads: NEVER OPEN HOT. At the bottom, it reads: INSPECT FALL & SPRING. Below that, it is stamped: stainless.

There is a copper rivet and a quarter fits in the middle depression.

Is this an anomolous production cap or just a service replacement?

Thanks for any helpful input.
Tony

[Peter L.]

Re: RC 15 radiator cap question

Tony - To answer your question squarely, it's a SERVICE replacement. 67 small blocks came equipped with RC-26 radiator caps not RC-15s. Pete

[Stephen L.]

Re: RC 15 radiator cap question

A photo of an RC-15 for a 67 BB with the circled info reversed.....I guess this could be one of the anomolies........

[Peter L.]

Re: RC 15 radiator cap question

Steve - Nice photo. You're correct in that it's not the usual orientation of the AC and the RC-15 but I've seen a number of them and I'll bet there are thousands of them out there so I like to think of them as production variations rather than anomolies, but to each his/her own. BTW, that's only one of the variable combinations and permutations you'll see if you start looking. Once again, they were making radiator caps (to make money) and it was important that they functioned (hopefully) when they went out the door not that the logo was oriented "correctly" so it could be "judged" 40 years later. Pete

[Philip C.]

Great Photo

Thanks Steve for that photo! Very very interesting, correct rivet,depression size, arrow length etc etc. Phil 8063

[Stephen L.]

Re: RC 15 radiator cap question

Its the original cap from my 67 BB. I refurbished/replated it since the photo and now I'm looking for the center vacuum valve portion that is on the reverse side, so I can put it back together. The original was damaged during disassembly... didn't know how it came apart...now I know...dumb mistake!!!

[Tony H.]

Re: RC 15 radiator cap question

Tony,
I agree with the answers provided so far in this thread. The picture provided show another anomaly or production variation and no doubt there are others. In the next article that is planned on the RC-26 caps, we will try to present more in the way of anomalies or production variations for that cap. While I believe there is a predominant configuration for these caps, the anomalies may be more than just onesies or twosies here and there in the production life of these caps.

When I do find a cap with an anomaly, I try to look at the other tell tale details to make a determination as to its authenticity/originality. As we learn more about these caps and see more examples we can become better judges. To the best of my knowledge, stainless steel covers were not used on radiator caps before and including 1972 model year. 1973 was the first year that stainless steel covers were used on radiator caps in the RC-33.