PCV on '57 T-Bird

[Milt K from Pa]

Barners,
PCV valves came up here not long ago. Most T-Bird parts suppliers sell a kit for a PCV upgrade. I get smelly exhaust in the cabin and noticed smoke, probably from the breather tube, from under the car. If I install the upgrade kit, which has a plate installed under the carb with a pipe exiting, to suck-in the fumes. This vacuum source attaches to the valley pan via a PCV valve and rubber hose into a grommet, where the breather tube would have been. How will this affect the tune of the carburetor, must I install different jets to richen it up to compensate for the loss of vacuum?? Will the sucking in of the smokey air cause gunk to build up in the manifold or foul plugs??

Anyone with experience on this upgrade, I would like to hear from you.

Is this a good idea or not???

Milt K from Pa

 

[paul2748]

While I do not have this conversion myself, I know a number of TBird owners that have it.

The vacuum source is the plate under the carb. It sucks in the gases in the engine into the plate and they go into the combustion chamber to be burned.

It should not affect the carb to any great extent. You may have to adjust the idle screws. No jet change is required.

I have not heard of any adverse conditions as far as the plugs are concerned and ditto on any gunk build up in the intake.

Barners,
PCV valves came up here not long ago. Most T-Bird parts suppliers sell a kit for a PCV upgrade. I get smelly exhaust in the cabin and noticed smoke, probably from the breather tube, from under the car. If I install the upgrade kit, which has a plate installed under the carb with a pipe exiting, to suck-in the fumes. This vacuum source attaches to the valley pan via a PCV valve and rubber hose into a grommet, where the breather tube would have been. How will this affect the tune of the carburetor, must I install different jets to richen it up to compensate for the loss of vacuum?? Will the sucking in of the smokey air cause gunk to build up in the manifold or foul plugs??

Anyone with experience on this upgrade, I would like to hear from you.

Is this a good idea or not???

Milt K from Pa

 

[Milt K from Pa]

Paul,
Thanks for the response, makes me feel better about installing it. The others you spoke of that did install it, what was "THEY'RE reason for installing?? Was it the same as mine, odor in the cab?? Did it accomplish its goal??
Thanks again.

Milt K from Pa

 

[blucar]

I have responded to the topic about installing a Positive Crankcase Valve (PCV) on a Y-block engine many times. The subject can be very interesting at times, this is due to the fact that PCV's are one of the most misunderstood items ever put on an engine.
A PCV is not a governmental conspiracy to make the internal combustion engine run poorly, it is a devise intended to make an engine run cleaner, and thereby better.
The adaption of PCV's in 1963 cleaned up 95% of the emissions that an engine released into the air we breath. By it's nature, the best engine has some blow bye caused by compression slipping by the rings and into the crankcase.. As the engine ages, the blow bye increases.. The PCV recycles the blow bye back into the engine where it is burnt off and expelled through the exhaust... To a certain extent the introduction of the crankcase vapors into the intake system tends to act as an upper cylinder lube.
I installed a PCV system from a '64 Ford 292 truck engine on my '57 Bird in about 1974. California had adapted smog rules that required after market systems that did not work, one system was called "NOX" which eliminated vacuum to the distributor. advance. The PVC system I put on my Bird made my engine pass the CA tests..
The majority of the T-Bird engines I have seen have a hole in the valley cover for the draft tube, this is a good place to start the PCV installation. The hose used must be at least 3/8" and the PCV must match the CID of the engine, approximately 300".. The plate must be between the carb base and the manifold. The fill tube must have a cap that will allow air to be drawn through the cap and into the engine.
The 292 truck engines had a metal adapter that attached into the valley cover with a 1/4 bolt, the hose then attached to a pipe on the top of the adapter.. A pretty slick setup.
Many years ago we found that generally after a PCV was installed on an engine, the carb would need to be leaned out a bit, we have now found that the modern unleaded fuels are very lean, therefore the jet size has to be increased..
Scrolling back through the FB topics about a week of so you will find several contributions about PCV's...

 

[blucar]

I took a few minutes to go out to my garage to take some pix of the '64 Ford truck PCV system on my Bird.
As you will note from pix 4, the access port in the valley cover is located under the vacuum access into the rear of the intake manifold. The limited space makes the '64 truck adapter almost a must have item because the pipe exits with a bend to clear the fitting required to hook up all of the vacuum tubes needed for power brakes, wipers, etc..
Since a pix is worth a thousand words, I have attached four pix of my system...

 

[Milt K from Pa]

Blucar,
Thanks for taking the time to explain and to add some photos. I see you ran the vacuum feed from the front of the engine, and wrap it around to the rear. I believe the ones sold by the T-Bird venders have the nipple on the rear of the carb base. This puts it close to the input into the valley pan hole, where the road draft tube would be removed. The only difficulty is going to be routing the rubber tube around the vacuum lines and brass fitting, which is right in the way, to get to the vacuum nipple. I'll have a better idea after I get the parts.

Thanks again for the help.

Milt K from Pa

 

[paul2748]

With the installation of the PCV system, you get rid of the draft tube and resulting smoke, fumes and smell and sometimes oil drips. I think these were the reasons for the change.

Paul,
Thanks for the response, makes me feel better about installing it. The others you spoke of that did install it, what was "THEY'RE reason for installing?? Was it the same as mine, odor in the cab?? Did it accomplish its goal??
Thanks again.

Milt K from Pa

 

[Hot Rod Reverend]

The best conversion I have done for PCV on an early Y block included what blucar has shown in his photos, but the TRUCK parts I used from a 63 or 64 (can't remember) also included a METAL TUBE that helped to route the line cleanly from the spout on that adapter at the rear back to the front of the carb. It tucks in nicely parallel to the passenger side valve cover. When I get back in town, I will have to take a few photos of it. I had always assumed that it was OEM equipment, but I am not sure. At any rate, it placed the PCV valve at the front of the carb.

 

[blucar]

How I plumbed the PCV system on my '57 Bird, places the PCV closer to the original opening in the valley cover, in lieu of cluttering up the area in front of the carb. I also pointed out that the offset pipe coming out of the draft tube adapter routes the plumbing away from the vacuum port distribution fitting..
Placing the vacuum plate with the vacuum fitting to the rear of the carb will place the hose in a manner that will cause it to kink, thereby reducing the air flow...
The original '64 292 truck PCV threaded into the intake manifold in front of the carb. With a four barrel carb, there is no room for a vacuum port in front of the carb.
As I recall I used a GM or Chrysler style of PCV, that had hose connections on both ends in lieu of being threaded on one end...
With the air cleaner on my engine, the PCV and related hose can not be seen.

 

[Milt K from Pa]

Blucar,
Received my PCV conversion kit for my T-bird. Since I have the manifold and valley pan off for painting, one question has come up. Looking at the PCV valve, it appears to me that it MUST be mounted in a vertical position, so that the floating inner valve closes in one direction. I'm not sure there is enough room under the manifold for the PCV to plug directly into the grommet into the valley pan.

I'll find out when I'm ready to assemble, but is that true, it MUST be mounted in a vertical position???

Milt K from Pa

 

[blucar]

I would not suggest that you place the PCV under the intake manifold.. The PCV has to be accessible for servicing... A rinse in solvent from time to time to keep the valve clear.
I would assume that the rubber grommet you have for the opening in the valley cover is similar to the one used in a GM valve cover.. If this is true, the PCV is also a GM type that plugs directly into the grommet...
On a T-Bird this might pose a problem because of the vacuum distribution block at the rear of the manifold.
The valve in the PCV is spring loaded. it does not know or care what angle it is placed in. It does have to be placed so the vacuum flow is towards the carb, source of vacuum.
The purpose of the spring loaded valve is to momentarily shut the vacuum off under accelleration, and thereby provide vacuum for the vacuum advance in the distributor..
As I have said before, the PCV is a very misunderstood devise.. So simple, yet it does a big job.
The stock '63-64 truck 292 PCV did have a metal pipe that connected to a short hose that was attached to the valley cover fitting. The metal tube was then connected to the PCV which was screwed into the intake manifold via a short piece of hose..
As I have said before, there is no room in front of a four barrel carb for a vacuum port in the manifold.. The metal tube also looks out of place next to the T-Bird billet valve covers..

 

[Milt K from Pa]

Blucar,
You are correct, the PCV valve I received is ment to be plugged directly into the grommet placed in the valley pan. But the valve I received has no spring return in it. I can see a steel "slug" in it, which is quite heavy, and just falls which-ever way you hold it. It has a number stamped into the valve of "2055", Made in USA. Any way of tracking this number?? I can draw air through it from either end, by mouth, in any position. I see no "one-way" flow pattern through the device. Doesn't seem to be a valve at all. It will probably suck the fumes in all right, but closing during hard acceleration doesn't seem possible. I can surely run the hoses from under the manifold to get the valve to a place where it can be serviced. But, do I have a properly functioning PCV or not?? Am I right in believing you must have a proper valve for the size engine you are running??

Does it seem reasonable that the T-Bird dealers selling these kits have done their home-work before putting them out??

I do appreciate your schooling me on these devices, I've never had occasion to work on one.
Thanks again.

Milt K from Pa

 

[Blackpearleb434]

Hi, here is a link that explains in detail how the PCV system works.....

http://mgaguru.com/mgtech/engine/cv103.htm

You will always have air flow through the crank case its just dependant on the level of vacuum your throttle position provides...if it was completely blocked off you could have a lot of pressure build up in the crank case.

Cheers

 

[Ole Don]

When I installed my PCV, my cover was on the bench. I used a punch and hammer to move the baffle down a bit dirrectly under the big opening for more room. Then I installed a gromet from a 302 V8 in the hole, and the PCV in the gromet. I use an Edelbrock carb which has provisions for a PCV. Any PCV should rattle when shaken.