Breathers/Oil catcher Tanks

[Biffo]

Has anyone out there removed the breather from the rocker cover to the inlet manifold/plenum and piped it to a breather filter/oil catcher tank ? I've heard it makes the engine run better/cleaner but some first hand experience would be re-assuring, especially what set up was used.

Cheers
Biff

[Jason]

What you're doing is venting the crankcase to atmosphere albeit via a catch tank. The oil vapourcondenses and that's what's "caught", ordinarily this would go into the engine and get burnt off with the fuel/air mix. So, in theory yes you have a cleaner combustion charge but quite what difference it makes I'm not sure - on a road car very little. The vapours still have to go somewhere so you can end up with a fumey little mess around your catch tank.
I used one for a while but soon realised that I had too much crankcase pressure caused, as I later found out, by knackered piston rings that were allowing far too much blow by.
If yoe're running a PI system, you need good engine vac and changing the routing of your breather will affect that.