Have you found this site useful? ...Help keep it on-line

Click a car to go to it's home page

   Emissions and Crankcase Ventilation 
   Breather System Design #2
   High manifold vacuum and rocker to cranckcase connection

   Emissions and Cranckcase Ventilation Issues

Home   Research and decision making    Standards and calculations    Exhaust scavenging     D-I-Y   
    My second design was geared more towards larger breather pipes, and attempting to control which pipe had how much flow and pressure in it.  This unit was made up of sqaure tube stock with multiple holes drilled in it. The idea was to direct the pressure from the rocker cover pipe, to the crankcase, and then pull air out another port, (pulling equally on both vents) and connected back directly to the intake manifold to maintain a vacuum in the crankcase at all times.


breathermodel2.jpg (12190 bytes)


This unit had a small verticle square pipe up the back that attached the larger second pipe, the screw driver handle is stuck down through (photo at left). The 'forward' tube is the seperator chamber in this design. The rocker cover vent pipe feeds into the pipe that sticks into the side (in front of the plier handles) of the rear box/tube.   

   This model unit worked well with the flow patterns as shown by the arrows in the next photo below, but....


     The green arrows show the air pressure flowing out of the rocker and into the side of the breather    box. The blue arrows, show the high vaccum direct manifold tap.  The red arrow show a secondary breather filter, incase the crankcase were to 'push' more air than the vaccum pipe could 'pull'.  The filter line has a PCV valve in it so the vacuum can not pull air in through it, but crank pressure could/can blow as needed.

     breathermodel1a.jpg (25472 bytes)

    I mentioned this setup worked, but....     What I mean is the pressure was reduced in the upper rocker cover, but I was still blowing oil out the rear lower crank rear seal. It was also hard to get the idle stable or the wide-band oxygen meter to read steady. And man! did this setup ever gunk up the intake! It was sucking oil into the intake big time!


breathermodel2filter.jpg (27297 bytes)

   A secondary 'output' filter was added to this version. The filter.  Again, the goal here is zero pressure build up in the crankcase. So I added a bracket under the edge of the brake differential switch on the bilkhead and mount he filter there.

breathermodel2filterpvc.jpg (6177 bytes)

I installed an off-the-shelf  PCV valve in the bottom of the filter. This was the largest i.d. PCV valve I could find and fit nicely into the hose as well as the bottom of the filter.

   Emissions and Cranckcase Ventilation Issues

Home   Research and decision making    Standards and calculations    Exhaust scavenging     D-I-Y   

return to Teglerizer's home Page©1987-2010
All material copyright© Teglerizer 1996-2008

last edited 

Hit Counter
hits since last reset

Paul's Triumph Home Page Paul's MGB Home Page Paul's MG Midget Home Page

index  Hit Counter