I recently added a PCV valve to my 1950 Buick 263CI motor. I was wondering if anyone else has ever done this. I did it in a way that will allow me to restore everything to original condition. I used an AC Delco PCV valve that GM used on many of their cars from large V8s to 4-cylinder motors. It did drop the engine vacuum from 22 to 16 at idle which is to be expected because the valve does present a controlled vacuum leak. I do not know if this is considered excessive. I will post more information and pictures if there is any interest. Please comment. I know there are many of you that are considerably more knowledgeable than me.
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DIY PCV valve installation on a 263 CI straight 8
- Thread starter JC3
- Start date
Do it yourself project articles.
The PCV, will open up when excess combustion gases are in the engine and feed them into through carburetor base. Can you describe what was the concern for you to decide to install a PCV? Just to mention on my 60s car it has PCV on passenger side and a canister oil filtered breather on driver's side. So, just wondering if you would need the same so that your vacuum doesnt drop so low.
It would be good if you uploaded pictures with description of what you did and if you change something in the future update it.
All we currently have on site is this brief PCV conversion article, CLICK HERE!
All we currently have on site is this brief PCV conversion article, CLICK HERE!
Thank you for responding. There are no problems with the motor. I did a compression test, and all of the cylinders registered between 128 and 135. The motor has 90k miles on it but there is no noticeable blowby. The car idles smoothly and accelerates as well as a 128 HP motor coupled to a Dynaflow transmission can in a car that weighs nearly 5000 lbs. I read a book about Chevrolet stove bolt motors that stated adding a PCV valve help to reduce the possibility of sludge build up in the oil and other benefits even on newly rebuilt motors. The oil filler cap contains a filtered breather that uses an oiled stainless-steel mesh
I am curious to know what the vacuum reading on your cars is and the part # of your PCV valve. A friend of mine let me look at his 69 Camaro with a stock 350, but there was no manifold vacuum I could check.
Thanks for your response. I tried to upload pictures, but I got a message that the upload failed, and the site admin would need to resolve. Here is verbal description. The draft tube is removed, and I found a plug that fit in the opening. I attached a fitting that allowed me to connect tubing with a double flared end and the other end of the tubing to a vacuum hose that fit the base of the PCV valve. This was done because the draft tube attaches to the bottom of a fitting on the pushrod cover which would cause the PCV valve to be upside down. This fitting contains baffles to prevent motor oil from being sucked out. Another hose is attached to the top of the PCV valve, and the other end is connected to manifold vacuum. I am not sure if manifold vacuum of 18 could lead to problems. The car runs and idles great with this setup. I did adjust the carburetor to have a slightly richer fuel mixture as stated in the articles I have read. Also, I believe California requires at least some vintage cars have PCV valves installed. I live in Delaware so there is no such requirement here. Here is a link to a picture of a Buick straight 8. You can see the fitting and draft tube between the oil filter and coil.
https://s3.amazonaws.com/images.mecum.com/auctions/ch1014/ch1014-195841/images/ch1014-195841_7.jpg
On the carbureted vehicles unburned gases dirty the oil more so than vs. Late model cars with fuel injection, higher ignition spark and sensors that keep things tuned and running cleaner. Also, the dip stick has a seal that when torn lets dirt to sludge engine oil.
look at the recent post on manifold vacuum it has pics.
look at the recent post on manifold vacuum it has pics.
oldfoneguy
Active Member
I had a quick thought, have you blocked off the original crankcase ventilation? Without doing so you have just created a massive vacuum leak and are sucking in outside contaminants. 6" hg seems like a rather significant vacuum loss.
mgaugustine
Member
An excellent point. I second the motion. Not that anybody asked...
I've adapted many systems to a PCV system going back to the 30's
It can be done on the down shaft/outlet tube you just need to install some kind of blocker so there is not so much vacuum loss.
A PCV does many things many/most don't know about usually all for the good IF done properly.
Tom T.
It can be done on the down shaft/outlet tube you just need to install some kind of blocker so there is not so much vacuum loss.
A PCV does many things many/most don't know about usually all for the good IF done properly.
Tom T.
Thank you all for your responses. I have gone back to the original draft tube, but I have not given up the idea of a PCV valve system. Oldfoneguy's comment made me think and I remembered Buick used to crankcase breathers. I tried blocking off one then the other and then both with no change in the vacuum level. I also tried a few different PCV valves. I will be doing more research but keep adding any additional information. I was finally able to add a photo of the PCV valve installation. The PCV valve is hard to see. It is attached to the pushrod cover and is partially hidden by the clamp that secures it. I will redesign the vacuum lines to simplified it next time
Attachments
There are two PCV systems : closed and open.
On a seperate topic I have started to notice a repeat use of "DIY" in title of posts. That is okay, but only if you are using it in correct content. Otherwise everyone is abusing it like, "Help!," followed by question.
Everyone is DIY on the car forums. Most of the time if you title with "DIY" the expectation is that you documented a project and are publishing an instructing narrative of a topic that you perceive will help other DIYers. Usually, images with an explanation would be in the post for educational purpose. We have some sample DIY (DYI) posts on the forum in select areas.
On a seperate topic I have started to notice a repeat use of "DIY" in title of posts. That is okay, but only if you are using it in correct content. Otherwise everyone is abusing it like, "Help!," followed by question.
Everyone is DIY on the car forums. Most of the time if you title with "DIY" the expectation is that you documented a project and are publishing an instructing narrative of a topic that you perceive will help other DIYers. Usually, images with an explanation would be in the post for educational purpose. We have some sample DIY (DYI) posts on the forum in select areas.