"Next time you look at a Pro-Stock car , see where they have the vents
in
the valve cover breathers routed to . Every time I see them , they have
them running all the way down and exiting the gases at the end of the
headers . "
They run them to the headers because the exhaust flow rate is so high
that they get good vacuum there, and the exhaust burns off the unburned
hydrocarbons that get past the rings because of the blowers.
On a street car, the egr is there for emissions only, it reroutes air
back into the engine to reburn a second time to clean up the exhaust.
The pcv system is actually beneficial-without it you would blow
gaskets out all the time (thats why they call it a positive crankcase
ventilation system) The engine pressurizes internally from the pistons
and crank churning, and the positive pressure is evacuated by a
controlled vacuum leak called a pcv valve. Without this system, your
oil would also become saturated with hydrocarbons and turn black faster,
because the pcv system reburns the vapors it pulls out of the crankcase
and heads. Installing the wrong pcv valve can also make your engine run
funny, because you have changed how big or small the controlled vacuum
leak is.
Patrick
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:09:47 EDT