Pipe Connections

[HappyZ]

What is the large tube sticking out just below the front carb?

does it connect to the balance bar?

If so, do they have to be connected with a hose?

can they be plugged?

can they be left open?

[SteveJ]

It is for positive crankcase ventilation. There should be a hose going from that to the PCV valve at the balance tube. 

They are parts 3 & 5 on this page: https://www.carpartsmanual.com/datsun/Z-1969-1978/engine-240z-260z/emission-control-device.

Hose: https://www.thezstore.com/page/TZS/PROD/15-6211

Valve: https://www.rockauto.com/en/catalog/nissan,1972,240z,2.4l+l6,1209169,exhaust+&+emission,positive+crankcase+ventilation+(pcv)+valve,5052

If you plug the PCV, you risk pressurizing your block and finding out how weak your oil seals are.

[siteunseen]

If you decide to buy the hose from MSA call them and give your CZC.com member ID, 33599 I think and you'll get 10% off.

[HappyZ]

@siteunseen what is MSA?  I've seen it many times, but never asked.

[SteveJ]

Motorsport Auto - http://zcarparts.com/

[HappyZ]

Do most owners plug the PCV valve and put a breather on the crankcase, OR keep it original with the hose?

[duffymahoney]

Datsun Spirit plugs the bottom, then just a breather filter at top.  

[SteveJ]

46 minutes ago, HappyZ said:

Do most owners plug the PCV valve and put a breather on the crankcase, OR keep it original with the hose?

Most of the cars I have seen keep the hoses.

[jfa.series1]

Keep the hoses!

[HappyZ]

Thanks everyone...I'll keep the hose

[HappyZ]

@jfa.series1what header is that on the motor pic you posted above?  My header won't let me install my carb heat shield.

[jfa.series1]

That is the MSA 6-1 unit, no changes required for the heat shield install.