Catch Can

[Dean]

Moved here to avoid poluting the Grimmspeed thread..

I am far from an expert, but have been thinking about this for some time.

I think the placement of the can and hose routing is critical to any solution, and failure to take those into consideration may well be the cause of many reported problems.

Even if a hose fills with oil, if that hose has a decent vertical component, the fluid pressure due to height should cause that breather to cease to breathe as it is no longer the path of least resistance. pressure should flow through internal passages and out another breather.

Scott's new A/O separator is very high relative to where I have seen some cans mounted on the passenger firewall. A passenger side vent run straight to such a can could have a very small vertical component and could even have a low point that could pool and then be bubbled into the can.

I am not sure of the routing since I have no full engine compartment to look at, but the stock lines that crossover on the intercooler may well be up there for just that reason instead of being low across the top of the block. There is not much higher you can get and not be sticking out of the hood!

Just something I have been considering for my rebuild.

[knucklesplitter]

Originally Posted by Dean

Moved here to avoid poluting the Grimmspeed thread..

I am far from an expert, but have been thinking about this for some time.

I think the placement of the can and hose routing is critical to any solution, and failure to take those into consideration may well be the cause of many reported problems.

Even if a hose fills with oil, if that hose has a decent vertical component, the fluid pressure due to height should cause that breather to cease to breathe as it is no longer the path of least resistance. pressure should flow through internal passages and out another breather.

Scott's new A/O separator is very high relative to where I have seen some cans mounted on the passenger firewall. A passenger side vent run straight to such a can could have a very small vertical component and could even have a low point that could pool and then be bubbled into the can.

I am not sure of the routing since I have no full engine compartment to look at, but the stock lines that crossover on the intercooler may well be up there for just that reason instead of being low across the top of the block. There is not much higher you can get and not be sticking out of the hood!

Just something I have been considering for my rebuild.

I think it's best to avoid "traps", ie. low spots in the breather lines that could collect oil. Some of the problems with the Crawford system that I have seen may have been due to trap areas.

As far as vertical rise in the lines I think that is good (if you avoid traps). It allows drain back of any residual oil maybe.