PCV valve

[Ed Ernst]

I've seen a few of these on Ebay lately.  Color coded PCV valves.  I worked on many cars back in the day and don't recall these. Are these valves legit or ?

http://cgi.ebay.com/ebaymotors/1969-CAMARO-CHEVELLE-NOS-CV746C-PURPLE-PCV-VALVE-1970_W0QQcmdZViewItemQQcategoryZ34198QQihZ018QQitemZ280186217798QQrdZ1QQsspagenameZWDVW

[tom]

There was an article in the November Muscle Car Review recently that stated the owner searched for years to find the correct purple pvc valve on Ebay. Photos also show the correct FORD "Caution FAN" sticker on the radiator shroud.

I don't remember color coded valves, but my attention back then was not on the emissions stuff, so I don't know.

Tom

[asm69]

As part of my restoration I purchased a pcv valve for a 1969 z28 about 20 or more years ago and it is purple.
If I get a chance I will post a picture of it. Don't know if they came from the factory like that.

asm69

[Dave69x33]

Here is a pic of mine.  The purple color is faded, but the color was not real predominant when it was new.   I purchased this PVC valve from an AC Delco Store cheap....about 8 years ago during my restoration.

[Dave69x33]

These discussions lead me to see if my local AC Delco store still had any "purple" CV746C PCV valves left.  It was my lucky day; they had one left collecting dust for $4.08.

The purple valve on the right is P/N-6484525, made by AC Spark Plug.  The one on the left was noted as a std. issue replacement for SB Chevy, P/N-6423695, made by AC Rochester, which is a CV736C.

Hopefully some can confirm this, but it appears the PCV’s are "calibrated" with a coded, internal weighted check valve to work with specific engines based on their vacuum draw, etc.  The CV746C is coded with a "K" check valve, the CV736C with an "M".  See attached pic's.

The 1969 Camaro AIM calls for:
P473, UPC Z28, PCV P/N-6484699
P101, UPC C8 covering the std. V-8, PCV P/N-6484541
P281, UPC A7 covering the 396 V-8, PCV P/N- none given, and states "Production Part"
P94, UPC C1 covering the L-6, PCV-6424191.

The "purple" valve sold on eBay recently, listed the CV746C fitting:
68-69 Camaro (302)
70-71 Camaro w/special high performance (350)
69 Corvette (427) w/430 HP
70 Corvette (350) w/350 HP, (454) w/425 HP
71-72 Corvette (350) w/330 HP LT1, (454) w/465HP
73 Corvette, Camaro w/HP (350).

Can any one confirm the K vs. M coding and the application for the CV746C?

Thanks
 

[rich69rs]

Looks like, according to the AC Delco Parts web site, that the only PCV valve that they officially stock for a 1969 Camaro, all V8 applications, small block or big block, is the CV736C valve. 

Gone the way of one valve works for all applications regardless of available engine vacuum.