I'm reinstalling a carbed 13B and it's got two tubes coming off the oil fill neck. Previously, these were just open and uncapped, and some oil would come out, with no other problems. I am hoping to route them back to the intake manifold, probably with a PCV valve inline like on many other cars. My question is: why are there two of them? What do I do with the other tube?

 

welcome to the board.

what year/vintage is the engine? i'm at a loss because i can't think of any 13Bs that had two nipples on the filler neck itself. do you have a photo?

 

Not OP but the 12a in my '83 FB had two fittings. One on the filler neck and one in the cast center iron maybe 2" below. I capped the lower one off and attached the PCV to the upper fitting.

 

The lower one connects to the charcoal canister. The upper to vacuum to ventilate moisture. To mani with a pcv is how mine is as well.

 

That makes a lot of sense. Thanks for the the clarification.

 

yeah, that's what i'm familiar with as well. however, i've been around long enough to try not to take certain things for granted when someone asks certain questions, so i just wanted him to clarify is all. there are some parts out there that i've never laid eyes or hands on and i like to try to keep that in mind.