CV590 or CV590C Cross Reference

[Joe C.]

From what I understand, these were used for 1963-64 Corvettes with Fuel Injection. Were they also used in L79 engines? If not, then what was? If so, then I need a cross reference to a replacement Purolator that has the same characteristics as that used on the 1964 L76 engine. Configuration is not a consideration.
Thanks.

[Mike L.]

Re: CV590 or CV590C Cross Reference

The CV590 PCV valve is a original for 1963-1964 only early FI units (375& 375R), the CV590c is a service replacement. If you have both valves together you WILL see a noticeably difference.

[Joe L.]

Re: CV590 or CV590C Cross Reference

From what I understand, these were used for 1963-64 Corvettes with Fuel Injection. Were they also used in L79 engines? If not, then what was? If so, then I need a cross reference to a replacement Purolator that has the same characteristics as that used on the 1964 L76 engine. Configuration is not a consideration.
Thanks.

Joe------


I'm not sure just what applications used the CV-590 during the 1963-64 model years. I have conflicting information. I believe that some applications during this period used a "calibrated orifice" instead of a valve.

In any event, as far as the CV-590 goes, it was used for some applications during the 63-64 period. The CV-590, GM #5649689, was discontinued in January, 1966 and replaced by the CV-590C, GM #6421934. I have forgotten just what the "C" suffix denotes but whatever it denotes, the CV-590C can be used in place of the CV-590 for any application originally using the latter. The CV-590 is of mostly "machined steel" construction while the CV-590C is mostly of stamped steel construction.

The CV-590C is now discontinued although I expect that will be plentiful on eBay and elsewhere. However, there is currently available from GM and AC Delco a replacement for this valve. It's AC Delco #214-2295 and also known as GM #19250958.

[Joe C.]

Re: CV590 or CV590C Cross Reference

Joe------


I'm not sure just what applications used the CV-590 during the 1963-64 model years. I have conflicting information. I believe that some applications during this period used a "calibrated orifice" instead of a valve.

In any event, as far as the CV-590 goes, it was used for some applications during the 63-64 period. The CV-590, GM #5649689, was discontinued in January, 1966 and replaced by the CV-590C, GM #6421934. I have forgotten just what the "C" suffix denotes but whatever it denotes, the CV-590C can be used in place of the CV-590 for any application originally using the latter. The CV-590 is of mostly "machined steel" construction while the CV-590C is mostly of stamped steel construction.

The CV-590C is now discontinued although I expect that will be plentiful on eBay and elsewhere. However, there is currently available from GM and AC Delco a replacement for this valve. It's AC Delco #214-2295 and also known as GM #19250958.

Thanks for the good info Joe.

Reason is that I eliminated the original .090" calibrated orifice (as well as the original intake, 2818 carburetor and a lot of other things) from my 1965 small block. My engine was originally an L76, and presently has a solid cam with idle vacuum comparable to the 1965 L76. It routinely winds quite high (7500+) and want to ensure that I have adequate ventilation at all RPMs.

I don't think that there is any published information regarding characteristics of the thousands of PCV valves that have been sold over the years. There is obviously a difference in plumbing, but I'm more concerned with operating characteristics.

I know that the 1965 SHP Corvette used the metered orifice, but I'm not sure about the 1964. Since I have no way of knowing the characteristics of different PCV valves, the second best thing I can do is to use one from an engine having similar characteristics to mine. The first two that come to mind are the 1964 L76, 1967-69 Z28, and the 1970-72 LT1. The '63 L76 used the Duntov cam which developed more vacuum at idle, so don't like that as a comparison. The original idea of using the 1963 PCV valve only is valid if this same valve was used on 1964 L76 engine with 30-30 cam.

I currently have a Purolator PV679 on it since it was fairly easy to plumb in using a hose into the oil fill tube and the PCV into the cut hose. Do you have an application chart for this valve as I can't remember why I picked it? Can you get the PCV valve numbers used for the early Z28 and LT1?

[Joe L.]

Re: CV590 or CV590C Cross Reference

Thanks for the good info Joe.

Reason is that I eliminated the original .090" calibrated orifice (as well as the original intake, 2818 carburetor and a lot of other things) from my 1965 small block. My engine was originally an L76, and presently has a solid cam with idle vacuum comparable to the 1965 L76. It routinely winds quite high (7500+) and want to ensure that I have adequate ventilation at all RPMs.

I don't think that there is any published information regarding characteristics of the thousands of PCV valves that have been sold over the years. There is obviously a difference in plumbing, but I'm more concerned with operating characteristics.

I know that the 1965 SHP Corvette used the metered orifice, but I'm not sure about the 1964. Since I have no way of knowing the characteristics of different PCV valves, the second best thing I can do is to use one from an engine having similar characteristics to mine. The first two that come to mind are the 1964 L76, 1967-69 Z28, and the 1970-72 LT1. The '63 L76 used the Duntov cam which developed more vacuum at idle, so don't like that as a comparison. The original idea of using the 1963 PCV valve only is valid if this same valve was used on 1964 L76 engine with 30-30 cam.

I currently have a Purolator PV679 on it since it was fairly easy to plumb in using a hose into the oil fill tube and the PCV into the cut hose. Do you have an application chart for this valve as I can't remember why I picked it? Can you get the PCV valve numbers used for the early Z28 and LT1?

Joe-----

The Purolator PV679 is configured differently than the CV590C. The PV679 is designed for an in-hose type of installation with 3/8" hose nipples on either end and is equivalent to Standard Motor Products V112. It was used on a large number of applications including, according to Standard Motor Products, 1966-67 Corvette small block. NO 1966-67 Corvette ever used a valve of this configuration. However, I believe that if this valve is used for 66-67, the PCV system has to be reconfigured for an in-line type of valve set-up.

All 1966-67 Corvette small blocks used valve CV-726C. This valve has a hose nipple on one end and an NPT fitting on the other. It is configured very much like the CV-590C.

The 1964 AIM shows no valve used for the L-76 application so, I presume, that means a "calibrated orifice" was used.

1967 Camaro with Z-28 used the CV-726C, same as all 1966-67 Corvette small blocks. The CV-726C is long-since GM discontinued. I don't know of an aftermarket replacement for the CV-726C. I expect that's why the PV679 and V112 are cataloged for that application (without mentioning that the system has to be reconfigured to use it).

All LT-1 used a different style PCV valve which inserted into a grommet in the valve cover. This is a CV-746C.

[Joe C.]

Re: CV590 or CV590C Cross Reference

Joe-----

The Purolator PV679 is configured differently than the CV590C. The PV679 is designed for an in-hose type of installation with 3/8" hose nipples on either end and is equivalent to Standard Motor Products V112. It was used on a large number of applications including, according to Standard Motor Products, 1966-67 Corvette small block. NO 1966-67 Corvette ever used a valve of this configuration. However, I believe that if this valve is used for 66-67, the PCV system has to be reconfigured for an in-line type of valve set-up.

All 1966-67 Corvette small blocks used valve CV-726C. This valve has a hose nipple on one end and an NPT fitting on the other. It is configured very much like the CV-590C.

The 1964 AIM shows no valve used for the L-76 application so, I presume, that means a "calibrated orifice" was used.

1967 Camaro with Z-28 used the CV-726C, same as all 1966-67 Corvette small blocks. The CV-726C is long-since GM discontinued. I don't know of an aftermarket replacement for the CV-726C. I expect that's why the PV679 and V112 are cataloged for that application (without mentioning that the system has to be reconfigured to use it).

All LT-1 used a different style PCV valve which inserted into a grommet in the valve cover. This is a CV-746C.

Here you can see my setup using the PV 679. The fit is perfect. It's the performance that I need more information about.

[Joe L.]

Re: CV590 or CV590C Cross Reference

Joe------


I've never found any performance specifications on these valves. However, I have found that certain valves are designed to work with engines producing low idle vacuum. The CV-746C is an example of such a valve.

Since I believe that your PV 679 valve is designed to replace (with system modifications) the CV-726C and since the CV-726C was used for all 1966-67 small blocks, I'd conclude that the PV 679 is at least capable of working with an L-79 level of performance.

[Joe C.]

Re: CV590 or CV590C Cross Reference

"1967 Camaro with Z-28 used the CV-726C, same as all 1966-67 Corvette small blocks. The CV-726C is long-since GM discontinued. I don't know of an aftermarket replacement for the CV-726C. I expect that's why the PV679 and V112 are cataloged for that application (without mentioning that the system has to be reconfigured to use it)."

"Since I believe that your PV 679 valve is designed to replace (with system modifications) the CV-726C and since the CV-726C was used for all 1966-67 small blocks, I'd conclude that the PV 679 is at least capable of working with an L-79 level of performance."


Joe,
According to what you wrote, the PV679 was used in an engine making much lower idle vacuum than the L79. Right?
If I read this right, then my valve should be what I need.

[Joe L.]

Re: CV590 or CV590C Cross Reference

"1967 Camaro with Z-28 used the CV-726C, same as all 1966-67 Corvette small blocks. The CV-726C is long-since GM discontinued. I don't know of an aftermarket replacement for the CV-726C. I expect that's why the PV679 and V112 are cataloged for that application (without mentioning that the system has to be reconfigured to use it)."

"Since I believe that your PV 679 valve is designed to replace (with system modifications) the CV-726C and since the CV-726C was used for all 1966-67 small blocks, I'd conclude that the PV 679 is at least capable of working with an L-79 level of performance."


Joe,
According to what you wrote, the PV679 was used in an engine making much lower idle vacuum than the L79. Right?
If I read this right, then my valve should be what I need.

Joe------


Yes, I neglected to consider the 1967 Z-28 application. So, I expect you do have what you need.

[Joe C.]

Re: CV590 or CV590C Cross Reference

Joe------


Yes, I neglected to consider the 1967 Z-28 application. So, I expect you do have what you need.

Alright!
Thanks for the verification.