1962 PCV valve 5649561

[Bruce T.]

I have found the previous posts that indicate the CV-202 PN 1552729 was used on the 1962 Corvettes until it was superceded by part number 5649561 in Dec. 1961. I think I also have found that 5649561 may cross reference to CV-693. Can anyone verify, that? A later catalog shows CV-693C is 6484851 (I think I read that correctly). What does a CV-693 look like?

I have a small collection of CV-590 and CV-590C PCV valves that I picked up in the 80s at the Pomona swap meet in California. I have one of the short black (2 5/16) valves and the longer version of that (2 9/16). I also have a bright colored version of the long valve and another bright long version but stamped CV-590C. From reading the other posts it sounds like the long valves date from 63 to 64, but the short CV-590 is early 63 or could be late 62. What was the part number of the early CV-590s in 1963? Edit: I have found the part number for the CV-590 to be 5649689 in Oct. 62 (per Dave's post) and then changed to 6421934.


I have a 62 Corvette with RPO242 that was built in February of 1962. So I am trying to determine what the correct valve should be.

[David L.]

Re: 1962 PCV valve 5649561

Bruce,

The PCV valve part numbers in the assembly manuals are NOT the same as the part numbers in the Chevrolet parts catalogs. I do not know why.

1552729 changed 12-6-61 to 5649561 in 1962 AIM
5649996 in 1963 AIM = CV590 = 5649689 in 63 parts catalog

The photo below is from Gr. 1.745 in my 1963 Chevrolet Parts Catalog (effective Oct. 1962). Unfortunately I sold my 1956, 1958, 1959, 1960, 1961 and 1962 parts catalogs several years ago because I thought that I no longer needed them.

Your CV590 PCV valve (2 5/16" long) is quite rare. Is it stamped "CV 590" or "CV-590"?

Dave

[Bruce T.]

Re: 1962 PCV valve 5649561

Hi Dave,
The 1552729 number in the AIM is the same number in my 1962 Chevrolet parts book from October of 1961. This book is apparently to early to show the replacement part number (5649561)in the AIM from December of 1961. It would be nice to see a similar page from a 1962 parts book published closer to the end of 1962 production.

I also attached a photo of the short black CV-590 (it has a dash) compare to a longer CV-590. I thought I had a long black CV-590 but couldn't find it for this photo. Unfortunately, my ruler didn't work well for this photo. I guess the camera was too close making the valves seem larger than the ruler, but I think it is obvious that the short valve is a 1/4 inch shorter.

[David L.]

Re: 1962 PCV valve 5649561

Bruce,

It is very unusual that the PCV valve AIM part number and the parts catalog PCV valve part number is the same but seeing is believing.

According to Chevrolet Parts History (over the counter parts) Gm # 1552729 was replaced with GM # 5646178 in May 1962 which was then replaced with GM # 6421785 (CV693C) in May 1966.

GM # 5646366 (CV-276) was replaced with GM # 6421787 (CV-695C) in March 1966.

GM # 5646184 (CV-208) was replaced with GM # 6421787 (CV-695C) in November 1965.

GM # 6421787 was discontinued in February 1976.

I believe that the 5646178 and 5646366 valves look very SIMILAR to the 5646184 valves. Enclosed are a couple of photos of a NOS 5646184 (CV-208) valve. The NOS CV-208 valve is stamped "TO MANIFOLD" with 2 stamped arrows, an encircled "AC", and "5846110". The black round paper-type ring has "AC" and "CV-208". There are also 2 hex areas for a 13/16" wrench. The valve still has about half of it's original black oxide type finish. The box is dated May 1963.

Dave

[Joe L.]

Re: 1962 PCV valve 5649561

I have found the previous posts that indicate the CV-202 PN 1552729 was used on the 1962 Corvettes until it was superceded by part number 5649561 in Dec. 1961. I think I also have found that 5649561 may cross reference to CV-693. Can anyone verify, that? A later catalog shows CV-693C is 6484851 (I think I read that correctly). What does a CV-693 look like?

I have a small collection of CV-590 and CV-590C PCV valves that I picked up in the 80s at the Pomona swap meet in California. I have one of the short black (2 5/16) valves and the longer version of that (2 9/16). I also have a bright colored version of the long valve and another bright long version but stamped CV-590C. From reading the other posts it sounds like the long valves date from 63 to 64, but the short CV-590 is early 63 or could be late 62. What was the part number of the early CV-590s in 1963? Edit: I have found the part number for the CV-590 to be 5649689 in Oct. 62 (per Dave's post) and then changed to 6421934.


I have a 62 Corvette with RPO242 that was built in February of 1962. So I am trying to determine what the correct valve should be.

Bruce------


Attached are photos of the original valve [not for sale].

As a functional replacement, you can use an AC CV-590C. However, be advised that the 590C has been recently discontinued. There should still be some around, though.

The original style valves could be disassembled for cleaning and service. Later valves are of crimped design and cannot be disassembled although they can still be cleaned with Berryman's B-12.

[Bruce T.]

Re: 1962 PCV valve 5649561

Bruce------


Attached are photos of the original valve [not for sale].

As a functional replacement, you can use an AC CV-590C. However, be advised that the 590C has been recently discontinued. There should still be some around, though.

The original style valves could be disassembled for cleaning and service. Later valves are of crimped design and cannot be disassembled although they can still be cleaned with Berryman's B-12.

Hi Joe,
Thanks for the reply and photos. The part number on this valve is 1552729 which is the valve used on the 62 Corvette until December 1961, and then replaced with 5649561 according to the 1962 AIM. 1552729 was replaced with another part number in May of 1962 according to one of Dave's parts history books.

I'm left with my original question, or maybe I need to restate it. What valve did the 1962 Corvette use after December 1961, and definitely after May 1962 when the 15552729 was discontinued?

The AIM indicates it was replaced with 5649561. What does this valve look like and what is it's CV number?

It seems that after the CV-202 was replaced for use on the 62 Corvette that it and it's replacements were used only on 283s. It looks like the CV-590 was the PCV of choice for the 327s after that, and definitely as a service replacement for the early 62 Corvettes. So, could an early 590 have been used on late 62 Corvettes, and would it have used the same part number used on the early 63s, or could it have had a different number?

Are there any late 62 survivors with RPO242 that still have the original valve? Are there any parts books dated between December 1961 anf the end of 1962 production that might give us more clues?

[Joe L.]

Re: 1962 PCV valve 5649561

Hi Joe,
Thanks for the reply and photos. The part number on this valve is 1552729 which is the valve used on the 62 Corvette until December 1961, and then replaced with 5649561 according to the 1962 AIM. 1552729 was replaced with another part number in May of 1962 according to one of Dave's parts history books.

I'm left with my original question, or maybe I need to restate it. What valve did the 1962 Corvette use after December 1961, and definitely after May 1962 when the 15552729 was discontinued?

The AIM indicates it was replaced with 5649561. What does this valve look like and what is it's CV number?

It seems that after the CV-202 was replaced for use on the 62 Corvette that it and it's replacements were used only on 283s. It looks like the CV-590 was the PCV of choice for the 327s after that, and definitely as a service replacement for the early 62 Corvettes. So, could an early 590 have been used on late 62 Corvettes, and would it have used the same part number used on the early 63s, or could it have had a different number?

Are there any late 62 survivors with RPO242 that still have the original valve? Are there any parts books dated between December 1961 anf the end of 1962 production that might give us more clues?

Bruce------

The problem here is just as Dave previously mentioned-----the PRODUCTION part number (the one found in the AIM) for these PCV valves is usually different than the SERVICE part number. I believe this may be because the PRODUCTION valves usually have no label or identifying "disc" attached and the SERVICE pieces do. However, the SERVICE pieces usually do have the PRODUCTION part number stamped on the valve, itself.

In any event, I have no way to relate the PRODUCTION part number of 5649561 to a SERVICE part number with respect to either the GM long number (7 digit) or the AC Delco "short number" (CV-xxx). However, I strongly suspect that the original AC CV-590, aka GM #5649689, was the valve used for later 1962 Corvettes with RPO 242.

Another thing: I assume that you are getting the date of December, 1961 as the change-over date from the AIM revision block. If so, keep in mind that date applies to the date the drawing was changed and rarely indicates the date the change actually took place on the PRODUCTION line. That date was usually at least 2 months later and, sometimes, much longer.

I think there is a lot of confusion regarding just what valves were used for these early PCV installations. For example, the P&A catalogs indicate that the 1552729 valve was used just for 283 applications but we know it was used for at least some 327 applications, including Corvette. A GM P&A Catalog dated 6/1/62 indicates that the 1962 Corvette application used GM SERVICE #5646190, aka AC CV-214. Then, a catalog dated 7/1/63 shows GM SERVICE #5649689, aka AC CV-590 for the 1962 Corvette application. However, the 5646190, aka CV-214, was not actually discontinued from SERVICE until September, 1983, so it's not as if the CV-214 was discontinued and replaced by the CV-590 sometime in the 62-63 period.

All this strongly implies a degree of "uncertainty" about which valves were used in the very early PCV period.

[David L.]

Re: 1962 PCV valve 5649561

Joe,

First of all, GM # 5646190 is an ADAPTER ASM. for a 62 Corvette, not a PVC valve (see 1962 AIM, Sect. 242, sheet 2.00). The adapter part number is 5645835 in the 1962 AIM. GM # 5645835 was replaced in 12/61 by 5646190 as per Chev. Parts History. Note that the adapter shown in my photo #1 attaches via threads to the PCV valve.

Second, I do not see how the "late" factory installed 1962 PCV valve can be the same as a factory installed 1963 PCV valve.

1962 AIM: 1552729 replaced 12/1/61 by 5649561
Parts History: 1552729 replaced in 5/62 by 5646178 then replaced in 5/65 by 6421785 (CV693C)

1963 AIM: 5649996 (CV590) = 5649689 (63 Parts Catalog) replaced in 01/66 by 6421934 (CV590C)

I assume PCV valve 1552729 must be used with adapter 5645835.
I also assume that PCV valve 5649561 must be used with adapter 5646190.

Note the difference between the adapter in the 1962 AIM (photo #2) and the adapter in my photo #1.

Bruce,

Which adapter do you have?

Dave

[Bruce T.]

Re: 1962 PCV valve 5649561

Dave,
The adapter in the first photo is for the 1961 Corvettes and is listed as Part number 5646189 (CV-213) in my October 1961 P&A 30 Revised. This adapter would use the CV-276 valve (5646366). The second photo is for the 62 and later adapter, CV-214 (5645835), which was on my car when I bought it in 1974. It appears to me that the CV-276 valve would flow in the opposite direction compared to a CV-202 or CV-590, and therefore would not be a compatible replacement for later valves that screw into the carburetor base or plenum rather than the adapter, as in 1961.

My guess on the replacement of the CV-202 is that maybe it didn't work that well on the 327 and was replaced (December 1961). The CV-202 was then later replaced on other applications with other compatible part numbers (cheaper, more producible?) in May 1962 but those applications were 283s from looking at the listed applications in various catalogs.

Joe, I like your way of thinking about the CV-202 possibly being replaced during the 62 model year by the CV-590. Sure would like to find some proof of that. But for my purposes, my car shipped on February 2, maybe there still were CV-202s on the factory floor and my Corvette got one of those originally.

Joe, What is the overall length of the NOS CV-202 that you have? Is it the same as the short or the long CV-590?

[Joe L.]

Re: 1962 PCV valve 5649561

Joe,

First of all, GM # 5646190 is an ADAPTER ASM. for a 62 Corvette, not a PVC valve (see 1962 AIM, Sect. 242, sheet 2.00). The adapter part number is 5645835 in the 1962 AIM. GM # 5645835 was replaced in 12/61 by 5646190 as per Chev. Parts History. Note that the adapter shown in my photo #1 attaches via threads to the PCV valve.

Second, I do not see how the "late" factory installed 1962 PCV valve can be the same as a factory installed 1963 PCV valve.

1962 AIM: 1552729 replaced 12/1/61 by 5649561
Parts History: 1552729 replaced in 5/62 by 5646178 then replaced in 5/65 by 6421785 (CV693C)

1963 AIM: 5649996 (CV590) = 5649689 (63 Parts Catalog) replaced in 01/66 by 6421934 (CV590C)

I assume PCV valve 1552729 must be used with adapter 5645835.
I also assume that PCV valve 5649561 must be used with adapter 5646190.

Note the difference between the adapter in the 1962 AIM (photo #2) and the adapter in my photo #1.

Bruce,

Which adapter do you have?

Dave

Dave-----


Yes, the 5646190 is the adapter; I "slipped a few lines" when I was checking this out.

The GM #1552729 and the GM #5646178 are exactly the same valve. Both are CV-202 and both have the number 1552729 on them.

Checking the June 1, 1962 edition of the P&A Catalog (and NOT slipping a few lines this time) the GM #5649689 (aka AC CV-590) is cataloged for 1962 Corvette applications with closed vent system.

Addendum: All of the 1552729 (CV-202), the 5646178 (CV-202), the 6421785 (CV-693C), the 5649689 (CV-590) and the 6421934 (CV-590C) would have required an adapter like the one pictured in the AIM. If the style pictured in the P&A Catalog was ever used on a Corvette, then that must have used some other PCV valve.

[Joe L.]

Re: 1962 PCV valve 5649561

Dave,
The adapter in the first photo is for the 1961 Corvettes and is listed as Part number 5646189 (CV-213) in my October 1961 P&A 30 Revised. This adapter would use the CV-276 valve (5646366). The second photo is for the 62 and later adapter, CV-214 (5645835), which was on my car when I bought it in 1974. It appears to me that the CV-276 valve would flow in the opposite direction compared to a CV-202 or CV-590, and therefore would not be a compatible replacement for later valves that screw into the carburetor base or plenum rather than the adapter, as in 1961.

My guess on the replacement of the CV-202 is that maybe it didn't work that well on the 327 and was replaced (December 1961). The CV-202 was then later replaced on other applications with other compatible part numbers (cheaper, more producible?) in May 1962 but those applications were 283s from looking at the listed applications in various catalogs.

Joe, I like your way of thinking about the CV-202 possibly being replaced during the 62 model year by the CV-590. Sure would like to find some proof of that. But for my purposes, my car shipped on February 2, maybe there still were CV-202s on the factory floor and my Corvette got one of those originally.

Joe, What is the overall length of the NOS CV-202 that you have? Is it the same as the short or the long CV-590?

Bruce-----


The CV-202 is 2.435" in overall length. However, the length of the valve is pretty irrelevant in the 1962 configuration. The only thing it affects is the length of the PCV hose and, then, only to an extremely minor degree.

[David L.]

Re: 1962 PCV valve 5649561

Pictured is a 3853194 adapter from a 1966 Chevrolet 327 Tonowanda engine that I bought in the 1980's for $25. The engine was complete and with all its original dated components (carb.,starter, distributor, M.T. flywheel, etc). The adapter looks very similar to the 1962 adapter as best as I can tell.

[Bruce T.]

Re: 1962 PCV valve 5649561

Thank you for the measurement. I wanted to compare the length to a similar valve that Tim B owns. Also I was curious because the CV-590 had a short version and for some reason made it 1/4 inch longer. Looks like the 202 was in the middle of those two lengths.

The evidence in your part book that the CV-590 was listed as a service replacement during the 1962 model year (June 1962) is great! It indicates that the CV-590 could also have been used in production late in the model year.

I would also be interested in what the 1962 Passenger AIM shows for PCV valves on RPO242. Since the passenger used both 283 and 327s in 1962, it may show the 327 switched to a new part number (same as Corvette) while the 283 continued to use the CV-202 for a while longer.

[Bruce T.]

Re: 1962 PCV valve 5649561

I'm posting this as a follow-up to my quest to find one of these. I found one on eBay about a week ago. I'll attach a couple of photos but the box is labeled CV 202 with part number 5646178. Someone has crossed that out and written in pen 6421785. This is a correct appearing CV-202 with the following stamped on it; "AC 1552729 TO MANIFOLD" with an arrow on each side of TO MANIFOLD. It may have had some surface corrosion that has been wire wheeled resulting in significant loss of the original black coating. Is that a date code in one of the photos and how does it interpret?
DSC01683.jpgCV-202 date code.jpgDSC01693.jpg

[Joe L.]

Re: 1962 PCV valve 5649561

I'm posting this as a follow-up to my quest to find one of these. I found one on eBay about a week ago. I'll attach a couple of photos but the box is labeled CV 202 with part number 5646178. Someone has crossed that out and written in pen 6421785. This is a correct appearing CV-202 with the following stamped on it; "AC 1552729 TO MANIFOLD" with an arrow on each side of TO MANIFOLD. It may have had some surface corrosion that has been wire wheeled resulting in significant loss of the original black coating. Is that a date code in one of the photos and how does it interpret?
[ATTACH=CONFIG]43103[/ATTACH][ATTACH=CONFIG]43104[/ATTACH][ATTACH=CONFIG]43105[/ATTACH]

Bruce-----

This is a somewhat later version of the CV-202 valve. The original valves had a black phosphate finish but after a relatively short period of time that changed to a zinc or cadmium finish. That's what this valve has, although it's somewhat deteriorated. Otherwise, the earlier and later valves are identical. I have NOS examples of both [none for sale].

I don't think the "1063-22" represents a date code. If it does, the zinc-finished valve I have was made on the same day as this one because I have an identical code on my box.

The 6421785 was a supercessive part number but it was configured differently than the 5646178.