PCV valves part #
Thread Starter
Racer
Joined: Mar 2014
Posts: 267
Likes: 24
From: Montevideo, Uruguay
PCV valves part #
Hello everyone
Maybe it's a stupid question, but anyways, here it goes....
I ordered a PCV valve for my 71 350cc 100% standard. The part number that I ordered and placed in the car is 19310788, but then I read somewhere that that part number is for a High Performance Engine, that the correct part number would be 19303069.
The engine runs perfectly, but should I change the valve despite that?
Maybe it's a stupid question, but anyways, here it goes....
I ordered a PCV valve for my 71 350cc 100% standard. The part number that I ordered and placed in the car is 19310788, but then I read somewhere that that part number is for a High Performance Engine, that the correct part number would be 19303069.
The engine runs perfectly, but should I change the valve despite that?
Safety Car
Joined: May 2001
Posts: 4,724
Likes: 1,628
From: Fairfax Virginia
Hello pifo1964,
The PCV is not a big issue unless your engine is losing oil around the PCV valve area or it is frozen in place (Internally). Remove the PCV and shake it, you should hear the valve move around inside. If not then I might replace it. The PCV is not totally unimportant and it is a good idea to use the Factory specified number for your particular engine unless If you want to play with the PCV there is a company called MEWAGNER.COM. Take some time and read what they have on their website and you will understand some of the engineering used to make the PCV and how you can customize one for your application.
It must be fun to have a Corvette in Uruguay. Are there many Corvettes down there? Can you still get good high octane gasoline down there? Expensive?
Best regards,
Chris
The PCV is not a big issue unless your engine is losing oil around the PCV valve area or it is frozen in place (Internally). Remove the PCV and shake it, you should hear the valve move around inside. If not then I might replace it. The PCV is not totally unimportant and it is a good idea to use the Factory specified number for your particular engine unless If you want to play with the PCV there is a company called MEWAGNER.COM. Take some time and read what they have on their website and you will understand some of the engineering used to make the PCV and how you can customize one for your application.
It must be fun to have a Corvette in Uruguay. Are there many Corvettes down there? Can you still get good high octane gasoline down there? Expensive?
Best regards,
Chris
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
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I'm not an authority on this. However what I do know is PCV valves are calibrated to different vacuum levels. When I put a bigger cam in my engine it now ldles at a lower vacuum level than with the factory cam. In the beginning I was having an uneven idle. I traced the issue to the PCV valve. I installed a performance PCV valve and my car has idled perfectly since. So, it does make a difference.
Thread Starter
Racer
Joined: Mar 2014
Posts: 267
Likes: 24
From: Montevideo, Uruguay
Hello pifo1964,
The PCV is not a big issue unless your engine is losing oil around the PCV valve area or it is frozen in place (Internally). Remove the PCV and shake it, you should hear the valve move around inside. If not then I might replace it. The PCV is not totally unimportant and it is a good idea to use the Factory specified number for your particular engine unless If you want to play with the PCV there is a company called MEWAGNER.COM. Take some time and read what they have on their website and you will understand some of the engineering used to make the PCV and how you can customize one for your application.
It must be fun to have a Corvette in Uruguay. Are there many Corvettes down there? Can you still get good high octane gasoline down there? Expensive?
Best regards,
Chris
The PCV is not a big issue unless your engine is losing oil around the PCV valve area or it is frozen in place (Internally). Remove the PCV and shake it, you should hear the valve move around inside. If not then I might replace it. The PCV is not totally unimportant and it is a good idea to use the Factory specified number for your particular engine unless If you want to play with the PCV there is a company called MEWAGNER.COM. Take some time and read what they have on their website and you will understand some of the engineering used to make the PCV and how you can customize one for your application.
It must be fun to have a Corvette in Uruguay. Are there many Corvettes down there? Can you still get good high octane gasoline down there? Expensive?
Best regards,
Chris
Here in Uruguay there are some Corvettes, mostly C4's, but you can find from all generations, including 3 or 4 C8 's. Personally, in addition to the C3, I have a C7 M7 Z51.
Regarding fuel, although refining is a state monopoly, the quality is reasonably good and using 91 octane gasoline it has not given me any problems.
The price is quite high, 1.8 dollars per liter, which gives more or less 6.65 x gallon
Best regards.
Pifo
Last edited by pifo1964; Mar 13, 2024 at 06:14 PM.
Thread Starter
Racer
Joined: Mar 2014
Posts: 267
Likes: 24
From: Montevideo, Uruguay
Thanks 4 Vette!
Mine idles perfect, I like it a little low, about 450-500 rpm in drive and about 100 more in P.
My doubt was simply because of the part number. I don't see any oil on the valve either, just a little bit of oil moisture on the part that goes inside the valve cover.
Mine idles perfect, I like it a little low, about 450-500 rpm in drive and about 100 more in P.
My doubt was simply because of the part number. I don't see any oil on the valve either, just a little bit of oil moisture on the part that goes inside the valve cover.
Race Director
Joined: Oct 2000
Posts: 12,613
Likes: 3,094
From: Shamong, NJ
The original PCV for 70-72 LT-1's was an AC Delco CV-746C - GM number 6484525, the base 350 and 454's used CV-736C (6423695). The only other application listed in the Corvette parts book for the CV-746C was the 68-69 L-88. The Z/28 302 and 70 454 LS-6 also used the CV-746C so there must have been a different flow rating for the value needed for high output engines like the LT-1?
Safety Car
Joined: May 2001
Posts: 4,724
Likes: 1,628
From: Fairfax Virginia
Thank you for the response pifo1964!
I personally am planning to convert my PCV valve to one made by the ME Wagner company. After reading the information they had on their web site I realized how the PCV was intended to work. Now that I understand them better maybe one might help my engine. I have always just replaced them with whatever number part was listed and never thought much about it.
On my 427 big block all a PCV does is keep the engine from building up internal pressure. I have taken the PCV out of the system and never had a hiccup or any problems. I don't think I fully understood what the original intention was and how they achieved it. I would highly suggest those interested to read the article as it is very educational.
Best regards,
Chris
I personally am planning to convert my PCV valve to one made by the ME Wagner company. After reading the information they had on their web site I realized how the PCV was intended to work. Now that I understand them better maybe one might help my engine. I have always just replaced them with whatever number part was listed and never thought much about it.
On my 427 big block all a PCV does is keep the engine from building up internal pressure. I have taken the PCV out of the system and never had a hiccup or any problems. I don't think I fully understood what the original intention was and how they achieved it. I would highly suggest those interested to read the article as it is very educational.
Best regards,
Chris
