Tech 101: Venting Crankcase Pressure

By Jeff Smith

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April 5, 2026If you see the dip stick pushed out of its tube even after a short time running the engine, this is an indication that there is excess pressure building in the crankcase. This could be because the PCV is not functioning properly or is plugged. The advantage of a PCV valve in any street engine is that it pulls a slight amount of vacuum in the crankcase, which lowers internal engine pressure and contributes to reducing oil leaks. Valve cover vents do not necessarily reduce pressure in the lower portion of the engine. We’ve discovered that the dual flow, adjustable M/E Wagner billet PCV can contribute to reducing oil leaks by lowering pressure in the crankcase. You can obtain an adjustable PCV valve through MEWagner.com

 

• I continue to perform the oil analysis on Model A engines with and without PCV systems and will present my findings at the MAFCA Nationals in June in Pendleton, OR. I am using the ME Wagner pcv valve and an oil / air separator as shown. I vent the engine from the valve cover on the other side. It works great as proven by the analyses. Previous oil leaks are gone on the engines (including the new Burtz engines) with the pcv system installed. Internal corrosion (from a mixture of moisture and acid precursors from the oil and blowby) is also a big problem on these old engines and the pcv system removes the moisture to minimize acid formation. The ME Wagner PCV valve is adjustable to match the engines, some of which are modified. If you want to see the data, please let me know. Thanks.
  
• JEBBER99Jeff, you’re better than this!
  Half a$$ description of what a PCV valve does, zero information on how to install and adjust this PCV valve.
  We expect more from you.
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    • RonSEven more of a reason the article could have gone into more depth.
      I feel like a lot of the gearhead mags/websites are afraid to get too far into detail and scare away the folks who just wash and wax their cars.
      Maybe I’m longing for the old days of Mopar Action and the old hot Rod magazines.