Newb question - I need help identifying these two hoses. The one on the left looks like a breather hose, the other some part of pcv. If the left is indeed a breather (it's oily) is it common to run this back to the air filter as this one does? Does anyone use a catch can for this as is done with other vehicles (like 2 others in my garage)? Thanks!

Aaron

Where do the other ends attach? The carb is a very non-stock (and not well-regarded) modification, so the attachments there won't really tell us anything.

--DD

Yeah, it's weber progressive (no comments please about how crappy they are!). The red hose ends up just north of the oil filler then into the bottom of the air filter plate - just an open hole coming out into under the filter element. The right hose goes into a junction that looks like vacuum hoses and into the same under-filter section though it has a plastic end with an o-ring seal. Hope this makes sense!?

By the looks of the photo the red comes off the PCV and is vented back into the air filter - common setup of the era.

The other hose in question is hard to tell in the photo and don't really follow your description, but it looks like you have vented heads based on the hose running down along the intake runners. So is the junction a T with hoses running to each head? If so, also common to vent the heads back into the intake.

Yes, a catch can be used in place of pulling it back into the intake which was done for pollution control in order to burn off the oil vapor.


- Scott

Actually I think the red hose is the head vent - here's from the other side.


Here's the typical vent setup on miata race cars - I'll just use a classier can

Chris at Tangerine Racing makes a new aluminum catch can with all the fittings. Not cheap, but a nice piece of kit as they say...

The red hose is connected to the PCV valve on the oil filler which vents the crank. Head vents connect to each head near the intake runners, on driver's side it is on cylinder two which is forward, on passenger side it is on cylinder 3 which the one towards the rear.

Based on your first photo, that looks like a head vent hose on driver's side just forward of cylinder 2's intake runner. My assumption is the black hose in question running to your air cleaner is connected to the head vent lines.

Ah, OK that makes sense now - the black hose goes to a junction, one for each cylinder as you say. So, I'm still assuming I can vent the pcv hose into a catch can? I don't know how it can do anything but foul up the air filter the way it is now