66-68 bb pcv valve tag

[Stephen L.]

Re: 66-68 bb pcv valve tag

Philip, Which PCV valve does your 69 have? #736 or 746? The correct tag for #736 is available in the NCRS Classified section, orange w/white lettering. It's under C2 parts.......

[Philip A.]

Re: 66-68 bb pcv valve tag

I will have to check when I get her off the lift. I re-read all theses posts again and I guess I missed the one from Mark Donnely that says 68 and newer didn't have one and apparently the judges deduct if one is present. So now this to investigate.

[Matt L.]

Re: 66-68 bb pcv valve tag

Hello everyone, i wanted to share an original 691 tag on my old 66 425hp Bowtie with 26k original miles. It was a great original unmolested car. i hope the pic helps you all out. I have hundreds of pictures of this car if anyone needs any reference.
Take care,
Matt Lewis66 vette exhaust clamps 1100.jpg66 vette exhaust clamps 1100.jpg66 vette exhaust clamps 1100.jpg

[Tim S.]

Re: 66-68 bb pcv valve tag

Thank you Matt.......that is the info I myself was looking for!!

[Matt L.]

Re: 66-68 bb pcv valve tag

Also wanted to add April build car VIN 19112

[Jack M.]

Re: 66-68 bb pcv valve tag

Backing up the 1966 images from Tim & Matt, here are some 1966 magazine road test images (published in 1965-66).
Unfortunately, magazine images are typically poor quality... with a halftone/dot pattern that further reduces details.
All the PCV labels seem to be hexagon shaped... light colored, with dark text.
I'll show the full magazine image... then zoomed into the PCV label:

1) This image is a scan from Sports Car Graphic magazine (Dec 1965)... the PCV tag does NOT appear round.
NOTES: According to the article, this test car came from DEALER STOCK... it was not a GM pre-production vehicle.
Hood prop is on the passenger side, so itz a fairly early car.
engine-01 (Sports Car Graphic - Dec 1965)-800.jpg

engine-01 (Sports Car Graphic - Dec 1965)-ZOOM.jpg


2) The next scan comes from Hi-Performance Cars magazine (June 1966)... the 'dirty' PCV tag does NOT appear round.
NOTES: Image #2 does NOT clearly display the hood prop in the photo, but it might be behind the fender cover...
There is snow in other images, so the actual testing seems to have taken place many months before publication.
engine-02 (Hi-Performance Cars - June 1966)-800-1.jpg
engine-02 (Hi-Performance Cars - June 1966)-800-2.jpg

engine-02 (Hi-Performance Cars - June 1966)-ZOOM.jpg


3) The last scan comes from Popular Hot Rodding magazine (Aug 1966)... once more, the PCV tag does NOT appear round.
NOTES: For #3, the hood prop seems to be a driver side.
engine-03 (Popular Hot Rodding - Aug 1966)-800.jpg

engine-03 (Popular Hot Rodding - Aug 1966)-ZOOM.jpg

[Danny P.]

Re: 66-68 bb pcv valve tag

My takeaway from this thread is this tag is not original. Correct?
Tim

With back up info and updated photos i think this is a real tag for a CV691 not the round orange white lettering one

[Ronald L.]

Re: 66-68 bb pcv valve tag

As rough as this engine looks, the 691 tag is too clean, and it is not rounded.

Original tags were round that has been cropped to make it hexagonal.

I have originals, and I also have thpse that were cut by a NCRS member with scissors in a very hexagonal shape.

My takeaway from this thread is this tag is not original. Correct?
Tim

[Ronald L.]

Re: 66-68 bb pcv valve tag

For more history on the 736 and 691 valves, you need to search this forum posts about ten years back there was a very well organized GM Part Number based assessment that was consistent with GM service publication of December 1965 where the 736 was was implemented on the 425HP engines.

Tags we present on pcv valves from AC Spark Plug in service until 1966 model year.

By June 1966 you will not find tags on these valves.

I have seen dealer finds of July 1966 dates valves, cases of 691 valves that do not/ did not have the paper tags.

How they would have could have survived - one cannot take a judging guide as the authority - the authority was GM, first a blue print, and second assembly plant instructions to install the part.

You have to remember - that in the later 1970s people were restoring these cars, hard to say what occured, NCRS was in its infancy focused on C1 cars.

However all the original 1967 solid 736 valves I have had or have used, did not have a tag around them, and if, like the original 691s, fare '63 fuelie pcv with label, they were removed and set aside for a new valve there would have been no reason to take the tag off

Steve,
I have had the die for the 691 valve label - its not available on the market because there is not a source for the real "paper".

It is not paper btw.

[Ronald L.]

Re: 66-68 bb pcv valve tag

Steve this one is real

Danny,
I don't know if this label is original or not.....PCV 691 label....... again, possibly a C2 judge can chime in..........

By the way, there is a difference between CV691 and CV736...... a different vacuum rating...... is it significant? I don't know....

[Danny P.]

Re: 66-68 bb pcv valve tag

As rough as this engine looks, the 691 tag is too clean, and it is not rounded.

Original tags were round that has been cropped to make it hexagonal.

I have originals, and I also have thpse that were cut by a NCRS member with scissors in a very hexagonal shape.

Ron if you have originals why don't you post them so the members could view them , thank you

[Matt L.]

Re: 66-68 bb pcv valve tag

Hi Danny, check out my pics. That one is original and how they should look for a 691 tag. Hope this helps.
Take care,
Matt

[Danny P.]

Re: 66-68 bb pcv valve tag

Hi Danny, check out my pics. That one is original and how they should look for a 691 tag. Hope this helps.
Take care,
Matt

Thank you Matt