Cam Cover Breather Hose

[PortRS]

I’m getting ready to start my 310S (driven here from California and parked in December) and noticed this odd hose configuration; a PCV valve was required for SB100 certification. 

 

This was done with two different hoses (second photo), what is the correct hose for the cam cover breather? Do I need the PCV valve? Thanks. 
 

 

[MV8]

The sigma 125/140 is routed like that. There is a different induction system for the EU 120 where the hose runs down between the runners then toward the throttle body. The pcv makes a handy adapter for the hose size mismatch and you may need it anyway for inspections. I don't see any benefit to removing the pcv but the J20R3 is not correct. Both hoses can be replaced with standard low pressure fuel hose J30R6,7, or 8. ISO standard 4079 covers oil and water based fluid transfer so the 1/2 inch hose might be ok. If either hose gets soft and gooey, makes your hand black handling it or the hose sweats, replace. I don't know what parts stores you have but I would go to O'Reillys or NAPA to find 1/2 inch fuel/emission hose or the HELP section for a hose that can be trimmed to fit. Dorman may not list the SAE standard on their product.

[PortRS]

Thanks! My car’s assembly manual shows the hose going down between the runners, but not how the other end connects. And all the photos I found of US 270/310 builds also show the hose in that position. Can I route it that way and leave out the PCV valve?

 

 

[MV8]

I don't know how it connects underneath on the other models/engines. It probably connects to some point between the throttle body and the air filter. It is a vent that may leak oil at times. Also, pcv's don't work well when mounted horizontal. A breather tank is a common addition to a seven. It could be connected to that and keep oil out of the induction system.

Bureaucratically, if you live in an emission testing county, the annual registration required to drive the car on public roads in Portland may hinge on the outcome of an emission test. That test may include a visual inspection that requires a visible pcv valve and no breather tank (which vents to atmosphere). The pcv has come up on other forums with bike-engined-cars (BEC "locosts") since the donor bikes do not have an automotive style pcv system but meet the fed standards.