Technical PCV valve

You are only partially correct. It is not just for venting pressure or emissions.

It removes combustion g***es that have made it past the rings. All engines, even when brand new, allow some by.

While that is indeed a smog issue, it is not the only reason that the PCV system is useful.

Left present in the oil, they cause the oil to deteriorate rapidly, leading to bearing wear and eventual failure of direct contact parts like cams/lifters, etc. A PCV system removes them almost instantly after they enter.

Also, and possibly more importantly, and one thing that your builder does not seem to understand, is that every single time the dew-point is reached where you live, moisture will condense out of the atmosphere, everywhere, including inside of your well-ventilated engine. A closed PCV system helps keep moisture out, and helps remove it as quickly as possible. That's something that a breather simply cannot do.

I put a PCV system on every single engine, from my lawnmower, to my Hemi, and everything else. I have engines out there that have reached the 200,000-mile mark and have not had, nor do they need, a teardown.

I don't know any experienced and qualified engine builders that recommend against a PCV system on a street-going vehicle, and I know a few dozen. None are crunchy granola eating tree-hugging hippies. All build engines that they don't want to see coming back on a truck, with an irate customer.

If you are planning on tossing out the coin to build a fairly uncommon engine, cheap insurance against premature failure is foolish to avoid.

 

yes there is

 

While we're on the subject...does anyone make a PCV grommet that fits tight...I've bought half a dozen different ones and they all fit sloppy at best....

 

If possible a breather with a hose fitting is the best. Then you can add a hose to the inside of the air cleaner between the filter element and carb. This makes it a closed system like mentioned. One photo shows the engine running and the PVC system I made holding paper before I turned it around. Its since been painted black.