Inliners International Forums General Discussion Engines PCV?

Can an older 235 be converted to PCV? I was thinking an aftermarket air cleaner with the provision and an oil cap that accepts a PCV valve (Mopar style?), and block the downpipe on the passenger side (if that's what it is). I would think it would be just as effective and alot cleaner?

Joe, Yes it can. Actually Chevy offered that as an option on the L6 at least in 1955. You can add one by drilling a hole in the down draft tube at the top and insert any modern PCV valve and connect a vacuum line from it to the wiper vacuum port with a "T" fitting. Then attach a vacuum line from the air filter to the valve cover drilling approximately 9/16 inch holes in each and use some sort of appropriate nipple.

There is no reason you can't convert the 235 to a closed crankcase, PCV, system. You could modify the road draft tube on the right side of the block to take a breather style cap that has a PCV in the center of it and use a conventional breather up on the front of the valve cover, or put a breather on the modified road draft tube and use the PCV type cap on the valve cover.
Ford used the PCV in the oil breather cap in the late 60's and early 70's as did other car makers and the aftermarket offers them as well in chrome.
For the exact PCV valve I'd suggest using one for the later 230 - 250 Chevy sixes. You can connect the hose to the engine on an unused intake manifold fitting or tee it with an existing vacuum fitting of adequate size. Your idle will be slightly effected and will require some minor carb adjustments due to the added air introduced from evacuating the crankcase.

Even the Ford Flathead guys are using PCV's these days.

Mike G

2 Cents

My 235 has been modified with the road draft tube described above. I have always driven my 235 powdered truck like is a modern truck. I have on a couple of occasions I had to make an abrupt slow down while driving at freeway speeds. When that happens, I got a huge amount of blue smoke out the tail pipe. I believe that it was oil in the oil pan sloshing forward and being picked up by manifold vacuum. I did make some mods to the pan when it was off, like baffles and increased the volume to 11 quarts. That may account for the oil being picked up. Just 2 cents.

Luis