Originally Posted by yragat
Besides spraying oil out of the breather pipe is there any advantage to converting to a PCV valve set-up?
Do you mean the road draft tube? The one that exits the bottom of the car?
Run a compression test. If it comes out good, run a leak down test. If it comes out good, a PCV system will help you.
Here's why. All piston engines, no matter how well they are built, will have some blow-by past the rings. The blow-by collects in the crank case. At highway speeds, assuming it is not plugged up and you haven't altered the car in a way which will alter the air flow past the end of the road draft tube, the air passing over the end of the road draft tube will draw the blow-by out of the crankcase. Around town or idling, not so much. The blow-by will mix with moisture in the air and create acids in your oil. Results - sludge (or more frequent oil changes) and premature engine wear. A PCV system increases engine life because the "positive" in positive crankcase ventilation is just that; positive (and all the time).
If the engine fails a compression and/or leak down test, it probably doesn't matter.