Draft Tube / Pvc Route Revisited / Question

[pflaming]

I have not changed my draft tube. Some have routed that tube back into the engine. Why and How?

[Don Coatney]

Check the resources link on the tool bar above. Go to downloads and look for factory PCV system.

 

PVC is polyvinyl chloride plastic pipe

 

PCV is positive crankcase ventilation

[JBNeal]

At some point, I will post more info on the PCV system I have installed on my '49.  I modified the stock draft tube with a fitting, routed some hard lines to a FF-Power Wagon PCV valve I found on eBay, then into the vacuum port on the intake manifold.  I also added a fitting to the oil fill tube, then routed some hard lines to a fitting I mounted on the top of the stock oil bath cleaner.  Both circuits are linked by the crankcase to vent volatile gases through the combustion chamber then out through the tail pipe, rather than venting directly to the atmosphere through the stock draft tube & oil fill tube breather cap.  There was a discussion about this with Grey Beard some time ago, I may have a link buried to it in one of my build threads found in my signature...at any rate, this system I have installed is based on the systems that DC is talkin'bout, and they work well.  I had a small backfire thru the carb on initial startup with this system installed, and it was clearly heard that the PCV valve slammed shut, doing its safety job...once the engine warmed up and ran for a while, no smoky vapors were observed venting from the engine compartment...parts of this system look something like this  
 

grey beard's thoughts on mopar flatheads

Edited January 30, 2014 by JBNeal

[MBF]

I did this modification a few years ago.  I immediately noticed how much cleaner the oil was staying between oil changes, and after dropping the pan and cleaning it during a gasket replacement after a valve job I was surpised that there was no sludge buildup in the lifter area or pan itself.  The 180 thermostat along with the filtered PCV system allows  the crankcase vapors and condensation to be removed via a constant vacuum instead of relying on road speed to vent the crankcase.  The PCV valve is basically a check valve to prevent a backfire in the manifold from igniting the crankcase vapors.  The key to efficiency from this update is that the engine must run hot enough to heat up the oil to a point that will allow it to vaporize any condensation that has been collecting.  I made my own system by cutting the tube off the draft tube and  welding on nipple.  From there I plumbed in a PCV valve to a vacuum port on the intake manifold.  For incoming air into the crankcase I used a newer styled valve cover vent plumbed into the air cleaner to make sure that any air entering the crankcase was kept as clean as possible.  There were several threads posted on this in years past.   Mike