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Working on a 327 from a 53 Patrician. Has anyone tried changing the road draught tube coming out of the rear valve cover to a line with a PCV valve back into the carburetor base?
Thanks,
Bob J.

The system requires the carburation be calibrated because 20% of the air intake at idle is from the PCV. EGR is 7% during cruise.

Having PCV and EGR improve engine longevity greatly which is why the Clean Air Act was not ruled unconstitutional when the auto makers fought it. When the customer is benefiting from a law it can't be ruled wrongful seizure of property (cash). As Iacocca pointed out though, requiring each manufacturer to develop their own systems rather than a cooperative system was a total economic waste paid for by the customer. That was the doings of Congress and a perversion of anti-trust laws.

Those systems were known in the 1930's, but automakers did not want the cars lasting longer.

There is an older discussion here where it was done and might provide enough info to answer questions. Different year but essentially the same engine. If you do a forum search for PCV valve there are several other discussions where various suggestions, considerations, and pitfalls have been noted.

This is great. I am on my way. Thanks for the wonderful info Howard.
Bob J.

One other consideration before you fully commit might be overall crankcase ventilation. When the prewar 356 was introduced there was an issue with rusting valves after an engine sat unused for awhile. This was found to be due to obstructions to airflow both in and outside the block resulting in overall poor ventilation. Packard made several changes to the external air supply to the point of even adding a special air flow tube to direct fan provided air into the oil fill cap to force ventilation before the rusting was finally under control.

When the 288/327 block came along after the war most of the improvements were incorporated and that engine did not seem to have valve issues. No idea how much PCV might disrupt the normal ventilation provisions of the engine but with a car not driven often possibly bringing a rust issue back is something to keep in mind. With only a few who have done this conversion there may not be enough data to say if this will be an issue.

I have seen PCV systems that were connected to the air cleaner. This method would not interfere with air-fuel ratios. This method had the hose from the crankcase go into the air filter housing. I think they were before and after the filtering. If after the filtering then a anti-backfire valve would be needed.