Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - on older engine--should convert to PCV valve setup?
View Single Post
  #12 (permalink)  
Old 08-31-2010, 07:43 PM
redsdad redsdad is offline
Will I ever get it done?

Last journal entry: Hood
Last photo:
Join Date: Oct 2004
Location: Tulsa, OK
Age: 60
Posts: 1,052
Wiki Edits: 0

Thanks: 1
Thanked 4 Times in 4 Posts
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.
Reply With Quote