PCV valve research...

[Roadster]

There seems to be concerns about the availability of the one unique PCV valve that is used on the LT5. Since we have a two valve system and they are a different size, it seems like it is difficult in finding one of the valve's in question.
Having a LS & RS, which is which, depending on which way you are looking at them. For our purposes and this may already be the correct way to identify them, I will refer to the LS as the driver's side and the RS as the passenger side. The RS is not a problem to purchase, but the LS appears hard to find.

When we did the plenum pull on the 94, I did not have the correct replacement for the LS, as most vendors do have a listing for the LS, but it really fits the RS. Go figure!!!
So I am still having my slight idle problem, and decided to make sure all hoses and clamps anywhere on top of the engine are secure and tight. Always do this before taking a long trip and at least every few weeks, whichever comes first. I get to the PCV valves and not only did the clamps need to be tighten, but the connector for the upper part of the PCV valves just lifted right off without much resistance. And it was a newer part. So keeping all of my old parts was a good thing to do, as I ended up reusing my original PCV upper connector. One thing that I noticed was that it was zip tied at the bottom to give a real good tight fit. I also removed the LS longer PCV valve and replaced with a regular RS one for now, and adjusted accordingly. Everything hooked and I thought maybe this is part of my idle problem, not so, but at least I addressed the loose connection. I would recommend to zip tie the bottom of the upper valve connector just to be sure you are getting a good solid connection.

I now am on a mission to find an AC Rochester CV 913 C "double hump" (as I will refer to the LS valve) for a LS replacement. Searching everywhere and researching again and again produced zero results. Finally (I hate giving up) I stumble across another "double hump" valve that has a different part number and will be here tomorrow. It is the same length which is 1 14/16" or 1 7/8" as the original, whichever you prefer and is an AC Rochester and another one (also to be delivered Wednesday) is an AC Delco. If they are correct I will then list the part number for those who are interested. But they be also getting hard to find.

The original LS PCV... CV 913 C from the 94....

[XfireZ51]

Have you thought of "sleeving" the connector?

[Roadster]

Originally Posted by XfireZ51

Have you thought of "sleeving" the connector?

No, to be honest I haven't. But that is an idea to be considered. For the time being the old connector is good and tight on the valves, you actually need a slight force to lift the connector off of them. The new one as mentioned came off with ease.

[Roadster]

Latest update for those interested....
I received my first AC Delco CV895C 25095452 today and it is a perfect match for the LS (driver's side) "double hump" PCV valve. Again the original number or earlier replacement number was CV913C. With that being said, it doesn't mean that you will get the exact valve in said packaging. Some sellers have shown the actual valve in their listing and some show the regular short valve. If you can find any and intend to purchase, it would be to your benefit to make sure and check with the seller that you are getting the correct valve. I have another one coming tomorrow and hopefully it is the same item.
Here are some pics showing the valves....

My original on the right with the new valve on the left. Exact duplicate...

A pic of all 3 valves with the far right one that is used for the RS (passenger side) valve. This is the one I temporarily used for the LS for a few days. That is the short one that usually automatically ships as a LS, but also can fit the RS when purchasing LT5 LS & RS PCV valves from most vendors or suppliers. The short one is the one that was listed for the LS and shipped from a previous purchase.

Installed on the correct sides.

Install complete....

[efnfast]

Why oh why would GM use two different valves????

[9T1 Red ZR1]

Tom,
Rock Auto shows V291 as crossing to the CV913C (one left in stock). I don't know if it is really correct though.

Bill

[Roadster]

Originally Posted by efnfast

Why oh why would GM use two different valves????

Don't know the answer to that one Steve, other than if you look at the configuration of the hose, you can notice where you insert the valves that it is offset. And due to that design, they needed two different length valves.
Maybe some of our LT5 experts can explain why!!!

Originally Posted by 9T1 Red ZR1

Tom,
Rock Auto shows V291 as crossing to the CV913C (one left in stock). I don't know if it is really correct though.

Bill

Bill,
I have ordered and received from Rock Auto and other vendors the V291 valve. I have about 4 of them now and each one is the short version, not the correct one at all. And you are correct, Rock Auto, ebay sellers and such do list the V291 as a replacement for the CV913C, but from my experience, that is not the case.
It would be good if there was a way to soak the old valves in some type of solution to eliminate the build-up that they accumulate over time so that they can be used again. I don't know if that would even be possible. It would also be good if we could find a manufacture to remake these "double hump" valves. But there may not be the demand or market that they would be lookin for.
I also found a listing for a certain Ford truck that showed a pic of the "double hump" valve in their listing. But when I asked what the size in length was, it was shorter that what we needed, it was just another "short" valve.

Anxious to get today's delivery, will update later today....

[efnfast]

I pour some gasoline in them, shake 'em up a bit and let them air dry. Don't know if that is an approved procedure or not.

[Roadster]

Originally Posted by efnfast

I pour some gasoline in them, shake 'em up a bit and let them air dry. Don't know if that is an approved procedure or not.

I was thinking more of soaking them in a parts cleaner solution for an extended time, or even spraying heavily with brake kleen. My luck using gas there be a spark somewhere and something would ignite and that would not be a pretty scene.lol.... Although the brake kleen is also combustible...

[Roadster]

Just received delivery of another PCV valve and it is the correct "double hump" valve with one slight exception. And that is the length, it is a tad shorter in height (I did not measure), which you can see in the pic. It should be no problem with the install.
Another interesting observation is the packaging, the one yesterday has the new type AC logo, while the one today has the old style AC logo. Well what difference does that make you might ask!!! If you get the newer style logo package, your CV895C valve is the exact height as the "original" valve which is stamped "AC ROCHESTER", while the replacement CV895C valve is stamped "AC DELCO".
If you get the older style logo package as I did today, your valve is stamped
"AC ROCHESTER", and again is a tad shorter. It appears that the original
CV895C valves were a shorter length to begin with and may not have been intended for the LT5. Although the stamped "AC DELCO" CV895C has the longer stem by a fraction.
The "AC ROCHESTER" CV913C valve has the longer and slightly different configuration stem. Either way, no biggie, they both work but are hard to find.
Also both style logo boxes have the same part numbers, apparently "Rochester" made the early valves and AC Delco made the later ones.

CV913C on the left, today's delivery of CV895C on the right. Notice the shorter stem.

Old style logo package...