Yes indeed Brendan, the closed circuit system on the late B18 & B20 can make setting the mixture a little variable, so the 142 has a catch tank from the rocker cover & flame trap breathers instead - interestingly after years of use, there's still only a very small dribble when I drain it. Rob
@@amazoncars That's interesting. I have a standard B20A and can never get it to idle smooth as if its pulling too much vacuum through the orifice nipple on the manifold. I am planning on reducing the orifice size in the manifolf nipple to see if it makes a difference or plugging it and vent the rocker cover down to the road.
@@brendanhurley8780 Brendan, on the closed circuit breather there should be a wee valve just above the flame trap. This closes at low revs to prevent the mixture going too lean, and opens at higher revs to burn the crankcase fumes. Rob
The early b18's also had a center filler but they are pretty rare
And lets not forget the B36!
that is mostly a clean slate design. A v8 truck engine.
On your 140 B20 you have an unusual crank crake breather piping configuration. Is it rally specific?
Yes indeed Brendan, the closed circuit system on the late B18 & B20 can make setting the mixture a little variable, so the 142 has a catch tank from the rocker cover & flame trap breathers instead - interestingly after years of use, there's still only a very small dribble when I drain it.
Rob
@@amazoncars That's interesting. I have a standard B20A and can never get it to idle smooth as if its pulling too much vacuum through the orifice nipple on the manifold. I am planning on reducing the orifice size in the manifolf nipple to see if it makes a difference or plugging it and vent the rocker cover down to the road.
@@brendanhurley8780 Brendan, on the closed circuit breather there should be a wee valve just above the flame trap. This closes at low revs to prevent the mixture going too lean, and opens at higher revs to burn the crankcase fumes.
Rob