1963 PCV Valve

[Ronald L.]

Re: 1963 PCV Valve

We would need to talk to the engineer for this in '63 to know why the early cars were not continuous flow.

But with the question on chatter I suspect it had to do with that - a customer complaint, in other words if the driver profile was such that you had lots of driving that was right on top of the point the valve opens, it could be easy to see where a complaint or functional issue could appear versus one that drops the hammer after every stop light. There's a lot more too these than what it appears at first glance.

[Michael H.]

Re: 1963 PCV Valve

Just curious about your description of the C.


Bob

Yup, me too.

[Timothy B.]

Re: 1963 PCV Valve

Just a side note FWIW, On my 67 300hp with it's original cv726c valve and the engine at that lazy 500 idle rpm which it will do, I have heard the valve rattle. Vacuum is still 19", I guess it's the pintle rattling against the spring when it bottoms out to restrict flow.

[Ronald L.]

Re: 1963 PCV Valve

Question for you '63 owners, is the label for the original 590 valve on this part from the factory, or not??? What does your '63 JG say, if anything?

[Bob J.]

Re: 1963 PCV Valve

The label sold by catalog companies was never used on production.
That was copied from pictures of pilot cars in the service manual.
Some feel a disc was used similar to the ones on early 691s.
There are examples of the disc from original cars and inside boxes of service 590 valves.
Bob

[Ronald L.]

Re: 1963 PCV Valve

I have a label (and the valve) that came off a car in 67 or 68 and it has a label, but is not similar to that of the 691 valve label.

[Michael H.]

Re: 1963 PCV Valve

The label sold by catalog companies was never used on production.
That was copied from pictures of pilot cars in the service manual.
Some feel a disc was used similar to the ones on early 691s.
There are examples of the disc from original cars and inside boxes of service 590 valves.
Bob

I agree. I think the valve and label shown in the service manual was a valve used for 62, not 63. The 63 valve looks much different.

The picture in the 63 service manual is from a pre production build at the engineering center. Not a production, or even a pilot line car. There are a lot of strange items on the engineering builds.

I don't understand what the 63 JG is trying to tell us. There is no mention of a tag.

"The PCV valve is either black anodized or brass finish. One known PCV valve is designated AV-V590". ???????????

Below is the PCV valve on 63 fuel injected Corvette, serial #00002, as it was going down the (pilot) assembly line. The same 590 valve that would be used for the rest of the 63 model year. I think all PCV valves in service had the round disc paper tag but I don't know if the tag was on valves in production.

[Ronald L.]

Re: 1963 PCV Valve

Michael,
I've not seen an AV valve designation and AC used the form CV-590 or CV 590 C. Anodizing of any color is a surface treatment for aluminium, not steel nor brass and I've not seen a brass AC valve either, that is looking at 62 to present.

They started out as black solid steel, either black phos or black oxide and w/o the lab test I'd suggest black oxide. About '65 they went to the same manufacturing process but zinc plated and then by about '68 converted the process to the thin wall stock - stamped or rolled steel.

I'm with you on all these valves, did the label come from the factory or was this a service item only?

[Michael H.]

Re: 1963 PCV Valve

Michael,
I've not seen an AV valve designation and AC used the form CV-590 or CV 590 C. Anodizing of any color is a surface treatment for aluminium, not steel nor brass and I've not seen a brass AC valve either, that is looking at 62 to present.

They started out as black solid steel, either black phos or black oxide and w/o the lab test I'd suggest black oxide. About '65 they went to the same manufacturing process but zinc plated and then by about '68 converted the process to the thin wall stock - stamped or rolled steel.

I'm with you on all these valves, did the label come from the factory or was this a service item only?

I've never seen one either. That was from the JG, not from me. That's why I put all the ?'s after the paragraph. The AV-V590 number sounds like an auto parts store replacement.

I have more factory pic's of new 63's without the paper label/disc on the valve but I also have a picture of the engine on a somewhat new 63 in a 1963 issue of Road & Track that does show the round label. Car had 5000 miles at that time so it's possible that the valve had already been changed.

[David L.]

Re: 1963 PCV Valve

Ron,

I collected several "black solid steel" CV590 PCV valves from junk yard 1963 Chevrolets back in the 1980's and none of them has a label.

Dave

[Ronald L.]

Re: 1963 PCV Valve

Dave, They are very fragile #1 and #2 we know that around 1967 the labels were discontinued. If there was a service procedure that called for changing these at 5000 miles, they'd be long gone by the time those cars hit the junk yard.

[Joe L.]

Re: 1963 PCV Valve

All------


I believe there were 2 types of labels. The early style is shown on the valve on the left of the attached photo. The later style is shown on the valve on the right. The early style label was printed on a very thin plastic material and glued in place. It was not very durable, at all. The later style (disc) is printed on some sort of thin, stiff, fiberboard. It is quite durable.

In any event, I do not think that either of these labels were on the valves used in PRODUCTION and I think that's why the PRODUCTION and SERVICE "long" part numbers differ. The Delco "short" part numbers (the ones printed on the labels) are the same for PRODUCTION or SERVICE.

[Bob J.]

Re: 1963 PCV Valve

The early label has not been seen on any car up till now that I know of.
Tony's Corvette in MD has an original car with the disc.
I have heard the 63 silver blue original conv from the 2010 national convention had the disc attached to the valve.
I have a NOS 590 valve in a 5-63 box with a disc.
If anybody has seen in person an early label on a 590 valve please speak up.
I honestly do not think the label was used on a 590 valve.
Bob

[Ronald L.]

Re: 1963 PCV Valve

The left valve is not a 590 and labeling would have been different on that style.

On the right valve... 590

I have a 590 valve with the real label which was intact on the valve, oily, and fragile.

The valve was taken off the car in either 67 or 68...and...the printing was NOT silver white.

[Joe L.]

Re: 1963 PCV Valve

The left valve is not a 590 and labeling would have been different on that style.

On the right valve... 590

I have a 590 valve with the real label which was intact on the valve, oily, and fragile.

The valve was taken off the car in either 67 or 68...and...the printing was NOT silver white.

Ron-----


NEITHER valve is a CV-590. I used them only as illustrative of the style of labels. The valve on the left is a CV-207 and the valve on the right is a CV-202. Both of these valves preceded the CV-590 in terms of time of release. Both of these valves were discontinued and replaced prior to mid-1966, so neither of the examples I have shown could be any newer than that.

The CV-202 shown in the photo is a later SERVICE example (later meaning after release but prior to discontinuation and replacement) as can be seen by the zinc plated body. However, I have a very early NOS example of the CV-202 which is black oxide and it has the early style label shown in my photo.

I do not see any reason why the CV-590 could not have used the early style label. However, it is possible that style label had been discontinued prior to the release of the CV-590.

My opinion would be that the style of label and/or the color of the printing was not related to the valve part number but, rather, was related to the time period that the valve was manufactured. I expect that the label style was used across the entire line of AC PCV valves during the period of use.