VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 PCV Valve Installation

Ok, the "tranny" thread got a little off topic, and the more I have looked into installing a PCV valve, the more confused I am. (I want to install one because I would like to keep my engine looking nice and clean.) So, a couple of questions.

Will any PCV valve work so long as you can make a tight, stable fit around the hole? Are a freeze plug and grommet necessary?

If I want to install it in line, again, will any one work?

It seems to me the important thing is to have a good seal around the hole. After that, what else is important to keep in mind?

Thanks for your help.

http://www.speedprint.com/deves50/pcvinstall.php

I used the parts described in this link. Everything worked great . Keep that oil dripping flow tube in case you need to sell the car to a hardcore restoration guy. I wanted to put the PCV vavle INSIDE the flow tube and have the flowtube chromed but gave up on that idea. Just a thought. I think all the parts needed were $15. That's about what a good concrete cleaner costs if you decide to not do this...grin

With any PCV system, you need a place to draw the air in and a place to pull the fumes out. The Deves article doesn't talk about the intake and he also mentions that he hasn't tested it yet. One of the places that you will probably draw air from in a 37 will be the rear of the crankshaft at the oil slinger. That is because there is no rear main seal. I have added a PCV system to my 1951 216 and I added a double action fuel pump to make up for the vacuum used by the PCV. It turns out that the PCV system did not really affect the wipers at all.

I added the PCV valve to the top of the draft tube and I blocked the road tube internally. This gives a good mounting point and the valve is further away from the crankcase.

Thanks wauwazit. That is the same link that I posted in your tranny thread. Where did you get the parts? The picture of your PCV valve looks a little different that the the one in the link. Where did you find the PCV valve, and how did you install it? (Sorry if I'm asking too many questions, but it's the only way I know how to learn things.)

With most PCV systems on early model engines the air enters the crankcase through the ventilated oil fill cap or similar and the PCV valve mounted in the crankcase or rocker cover and a hose then connects to the engine side of the carb. The valve will close off by vacuum at idle and as throttle opened and vacuum decreases it opens. Later systems the crankcase is sealed and air intake is connected to air cleaner body between filter and carb opening.

Tony

I got everything from NAPA. Almost any PCV valve will work,just get one that fits the rubber grommet. Try it, you'll like it.
I had another oil leak, in the fuel pump. Under the pump there is a small pin that the flipper device attaches to the body of the pump. That pin would move from side to side and drip oil. A good place to look if you have a dirty engine. I bought a new double vacuum pump and got rid of that leak also. These engines do not have to leak oil, it's just a matter of finding the leaks.
I spent a afternoon under the car just tightening bolts and nuts that were loose. The Ball/Bell gaskets were my worst problem. That's a pain to take apart and replace because of the emerg. brake and universal joint being so hard to get back together. If you had a lift it wouldn't be that bad, but I don't.
Good luck with the PCV valve. If you don't like it, you lost $15. Save the parts and let someone else try it.
It's embarrassing to have an old car and not be able to park it without throwing an old rug under it to soak up the oil.

If your 37 motor is like the 38, the oil filler is part of the road draft tube. If you remove the tube you will have nowhere to put oil in. I am basing this on my 1938 216.

If a home made PCV system is added just plug up the bottom end of the road draft tube.
Adding the PCV system draws some vacuum which then leans out you fuel/air mixture so a slightly richer jet may be necessary. The PCV valve should be from an engine with about the same displacement as a 216.
The ideal place to have the PCV valve located in the rocker arm cover so as to draw the fumes out of that area as it is most prone to sludging up. Thats what Chevrolet did.

True. My engine is a 235 with a breather in the valve cover. I don't have an oil filter at all.