Dealing with a disconnected smog system......

[uhoh7]

This is a 73 Z with 3 mikunis and a 6 into 2 header, which I have just got.

The valve cover vents into a k&n filter in the engine compartment--not connected to intake and I'm not positive if there is a PVC valve stuck in there.

The crankcase vents to a stinky filter/cover which fits over the pipe on the left front of the motor

The gas vapor return lines from the resevior enter the fuel vapor control valve, then 2 vacum sized hoses come out of that valve and are cut. They do not appear to be plugged.

Fumes are a concern, and I wonder what suggestions you guys might have to deal with these engine compartment contaminators?

Thanks

Charlie

[Ricklandia]

I'll give it a stab, without seeing a photo. I'm sure some meore knowledgable guys will correct me where needed.

1. Valve cover vent into K&N filter - that's fine. I believe that will draw in air to the crankcase if: (see #2)

2. The crankcase should be vented via a hose to the intake manifold at the center of the crossover tube. DOH! I forgot... triples (lucky stiff). The idea is you want to have the crankcase vented with an active pressure mechanism, ie. sucking air out on one end and sucking air in on the other.

Is there a free vacuum port on the manifold you can use?

Although it may not sound like it (sucking dirty, oily air into the intake manifold), good grankcase ventilation will actually make for better performance than without.

3. (Broke out the FSM for this one) The fuel tank vapor line should run into the (fuel) Flow Guide Valve (bolted to the fenderwell). The Flow Guide Valve has three markings on it A, F and C. The fuel tank vapor line goes into F, the upper port labeled A goe4s to the air cleaner (or any outside air source) and the post labelled C goes to the small port just above where your crankcase vent is (see #2).

The preinciple is that tank vapors vent to the crankcase when the motor is not runniing, NOT the air cleaner. When the motor starts, any fuel vapors in the crankcase get cleaned out by the positive crankcase vent systems (again, see #2).

If you want, send me a PM and I can scan the FSM pages for ya. I'm glad you asked, I'm sorta in the same boat; PO disco'd all the emissions stuff and I found the vent lines at the flow guide were reversed.

[uhoh7]

I apparently have an original Datsun Competition manifold and carby

setup. This according to Wolf Creek Racing who have seen good pics of the setup. I will have to look but I fear there are no unused vacum ports on the intake.

I have seen pictures where these vents are routed to a "dump can"

I am going to look for the "the small port just above where your crankcase vent is" Hope i can find that one!

Thank you so much for taking the time to reply

Charlie