Posted By: Phak1 Replacement PCV Valve - Wed Nov 06 2019 01:52 PM
Having recently obtained a NOS Ventilator Assembly (3698844) for my ’59 235, I’m now looking to assemble the rest of the parts needed to complete the system. I’m not going to drive myself crazy looking for all of the original parts but instead I just want to get the system to function correctly. The ventilator assembly has a 1/4” female NPT thread. The original PCV valve has a 1/4” male NPT and it appears to have a tubing fitting on the other side. Its part number 1544935 as per diagram from RPO 417 sheet 1.00.

I’m looking for a replacement PCV valve that has 1/4” male NPT on the inlet side and a nipple for hose on the other. I think that would be the easiest option to hook this system up. But sizing the valve for the correct flow is my problem.

Any suggestions?

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Posted By: rfs56trk Re: Replacement PCV Valve - Wed Nov 06 2019 04:17 PM
Military vehicles used a threaded PCV valve. Take a look at the Kaiser Willys catalog. They show a valve with a male pipe on one end and a female pipe on the other.
Posted By: Wrenchbender Ret. Re: Replacement PCV Valve - Wed Nov 06 2019 04:23 PM
The small block Chevs from the mid 60's had a PCV valve on the back of the carb with 1/4in. pipe threads that screwed into the back of the 2 barrel carb.
Posted By: Hotrod Lincoln Re: Replacement PCV Valve - Wed Nov 06 2019 04:25 PM
Check Ebay for "vintage PCV valve"- - - -there are dozens of them listed, and a lot of them have male NPT threads. Pay close attention to the direction of flow- - - -the NPT thread is the inlet side on the correct valve.
Posted By: Phak1 Re: Replacement PCV Valve - Thu Nov 07 2019 04:04 PM
I thank you all for your suggestions. I was hoping that some of our fellow ‘Bolters” may have run into this and solved this issue. I have looked at all of your suggestions and they would all work to make the connections, but the flow is what I am most concerned about. To much flow and the engine and wipers won’t work properly and too little the system won’t evacuate the vapors. I suppose I may have to be the guinea pig and experiment with different valves. On Deve’s site, his testing for PCV valves said he was looking for 1 to 3 Hg vacuum measured at the oil dip stick tube to get the proper flow.

As to the direction of flow, I suppose where the valve is mounted doesn’t matter as long as the direction of flow is correct. Some of the valves I have seen the direction of flow is toward the male NPT thread. In this case the valve could be mounted at the manifold.

Your thoughts would be appreciated!
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