1969 pcv

[Floyd B.]

There seems to be something broken with the search function on the forum. Even a search string of "pcv" returns "no matches" so I'll post a new thread. My apology if this has been answered a 100 times before. I have seen a few different versions of the CV736C. Some have AC ROCHESTER on line 1 and TYPE CV 736 C on line 2 and an M stamped on the bottom of the floating plunger. Others have AC SPARK PLUG on line 1 and TYPE CV- 736C on line 2 and a D stamped on the bottom of the floating plunger. I think I've seen a few other variations including the new service replacements with AC DELCO (in italics) on line 1 and CV 736 C on line 2.

Which was my 69 L36 shipped with?

[Don H.]

Re: 1969 pcv

Floyd
nothing wrong with the search function,
note that you cannot search words with fewer than 4 letters. The returns would be too great. Here is the information from the FAQs on searching.
What is the minimum word length (4) and how do I find what I want
"In order to limit the load on the server you should not search on words less than four characters in length. If you need to find phrases with short words you can work around this.
You can't search on "Big Block" because "Big" has only three letters. You can substitute a percent sign (%) for the space and create a word that is 9 characters long. "Big%Block". This will work on any phrase that you might need to find. Be sure to include the " (quotation marks) for best results
For single words or acronyms with less than 4 characters you may need to use an * asteric. %FI doesn't work, but *FI does."

[Russ S.]

Re: 1969 pcv

Floyd, I don't have a 69 Judging Guide but don't they say?? Sure should.

[Floyd B.]

Re: 1969 pcv

No. It doesn't provide that level of detail for the PCV.

[Joe L.]

Re: 1969 pcv

There seems to be something broken with the search function on the forum. Even a search string of "pcv" returns "no matches" so I'll post a new thread. My apology if this has been answered a 100 times before. I have seen a few different versions of the CV736C. Some have AC ROCHESTER on line 1 and TYPE CV 736 C on line 2 and an M stamped on the bottom of the floating plunger. Others have AC SPARK PLUG on line 1 and TYPE CV- 736C on line 2 and a D stamped on the bottom of the floating plunger. I think I've seen a few other variations including the new service replacements with AC DELCO (in italics) on line 1 and CV 736 C on line 2.

Which was my 69 L36 shipped with?

Floyd------


Original valves were stamped "AC Spark Plug". That's for sure. All others are later replacements.

With respect to other features, I'm not sure. These 736C valves changed in several ways over the years although the part number never changed. So, it's hard to pin down just when the changes occurred.

Original valves had either 4 "punch marks" around the base or NO punch marks. Any valves with 6 or more "punch marks" are later valves. This feature usually separates out about 90% of the "NOS" valves seen available for sale.

It's even possible that 1969-era CV-736C valves were configured like their predecessor, the AC 691C. I'm just not sure about this.

[David L.]

Re: 1969 pcv

I have 8 CV-736C valves. In my opinion the 1969-1972 CV-736C valves had 4 punch marks around the base. I have several of these valves from salvage yard 1969 and 1970 Chevrolets that I obtained back in the 1980's. I also have a few NOS valves that have dated on the boxes.

The "early version" valve on the left in the photos might be the 1968 version but that is just an educated guess.

Dave

[David L.]

Re: 1969 pcv

Here is a photo of a 1967 Corvette valve that is owned by another NCRS member.

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[Joe L.]

Re: 1969 pcv

Here is a photo of a 1967 Corvette valve that is owned by another NCRS member.

.

Dave-----



This one is the configuration of the predecessor AC-CV 691C. So, this confirms that the very early AC-CV 736C valves were configured like their predecessor. I do expect, though, that this configuration AC-CV 736C was most likely used only during the 1967 model year and, possibly, early in the 1968 model year.

The AC-CV-691C, GM #6421981, was discontinued from SERVICE in July, 1969 and replaced by the AC CV-736C, GM #6423695.

[Gary H.]

Re: 1969 pcv

Floyd,

I went through 2 rounds of regional judging using the same pcv. At nationals and at BG I was told for the first time that it was a service replacement as it didn't have the 4 dimples, had more.



Gary

[David L.]

Re: 1969 pcv

Dave-----



This one is the configuration of the predecessor AC-CV 691C. So, this confirms that the very early AC-CV 736C valves were configured like their predecessor. I do expect, though, that this configuration AC-CV 736C was most likely used only during the 1967 model year and, possibly, early in the 1968 model year.

Joe,

I tend to agree with you that the 1967 "machined" style 736 valve very well could have been used in the 1968 model year. I also believe that the longer stamped steel 736 valve (1.68" long on left side as shown in my photo) could have also been used in the 1968 model year. I must have got in a salvage yard many years ago but unfortunately failed to "bag and tag" it as at that time I thought all 736 valves were the same.

Dave