Stant Oil Fill Cap

[Loren L.]

The 66 JG talks about base motor oil fill cap as one with an S on the center rivet (I can only find one rivet, so.....); the 67 JG describes it virtually the same way but adds information about an SM logo in a circle adjacent to the center rivet.
Mine has the SM logo - does that mean I have a 67 - or does it mean that the 66 JG is incomplete?
I guess that I'd describe the finish as either natural or "gray phosphate".

[Stuart F.]

Re: Stant Oil Fill Cap

Loren;

Hang in there. You should get some responses today.

Stu Fox

[Jack H.]

Re: Stant Oil Fill Cap

There's a similar issue with gas caps. The type/style of the Stant corporate logo changed over time to effectively 'date' when this/that cap was made. The early form of the emboss, was 'SM' enclosed with a 'C' all surrounded by a circle making the emboss look like SM inside a double circle. The later version of the logo was a single 'S' in block letter format...

The SMC verison is thought to be correct for mid-year cars while the block lettered S version is thought to agree with Shark era cars and service replacement parts. Just when similar changes on the oil cap took place, I can't say...

[Joe R.]

Re: Stant Oil Fill Cap

Hi Loren:

My 67 cap has the "S" on the rivet but no additional SM logo. I have looked at quite a few original base engine oil caps and have never seen the additional SM logo. If it did appear on some caps, I don't think it was on all of them.

I also have a couple NOS caps, and they don't have the extra SM logo, either.

It seems odd that SMC would feel the need to mark their caps twice, since the "S" in the rivet would be adequate to identify the manufacturer.

Regarding the finish, I believe that most original caps had some sort of plating finish with an "olive-drab" color. As I recall, the 1967 JG accepts either this finish or semi-gloss black paint.

[Joe L.]

Re: Stant Oil Fill Cap

The 66 JG talks about base motor oil fill cap as one with an S on the center rivet (I can only find one rivet, so.....); the 67 JG describes it virtually the same way but adds information about an SM logo in a circle adjacent to the center rivet.
Mine has the SM logo - does that mean I have a 67 - or does it mean that the 66 JG is incomplete?
I guess that I'd describe the finish as either natural or "gray phosphate".

Loren-----


I agree with Joe. Every one of these caps that I've seen have only the "S" on the center rivet and no other markings. Is it possible that some might have the additional "SM" stamping? Yes, it's certainly possible. There were likely multiple sets of tooling for this piece considering the PRODUCTION requirements in the 66-68 period. However, I've never seen one with the "SM". I have many NOS examples of this cap, GM #3881834, and none have an "SM" marking. Some of the ones I have are "real old" NOS, too.

As far as the finish goes, the GM specs specify "black zinc". This is the finish that often imparts the slightly "greenish" hue to the piece. It's an odd-ball finish and was rarely specified. All of the ones I have evidence this finish. Why was it specified in this case? I have no idea.