PCV and Smog systems removal '73 240z

[mandtw]

I am currently in the process of swapping out my '73 hybrid motor (stuff from whatever) with a '81

ZX motor , 5 speed and 4.11 rear end. I am keeping carbs instead of EFI. I will be using header type system for exhaust w/2 1/4". my question is what is the necessity of the PCV and smog equipment? I have studied various posts and articles but, have not come up with a definitive solution as to remove or leave. What impacts can I look to incur if I remove smog system. I have looked at various PCV diagrams and have noticed some of you have installed a breather filter, I would have to have to assume that the PCV valve was left going to the block vent. Also is it necessary to leave the tank pressurizing system hooked up? I would greatly appreciate any feedback. -Tom - stranded in California City.

[smg1404]

Unless you are trying to create a fully restored car, there is no reason to keep any of that Junk... Normally I would say park a trash can next to the car, and fill it up.... But some of the other members of this site may want those power robbing parts.... Just remember to plug any holes left in the intake system when they are removed, and everything should work out fine..

[dohc]

I've stripped everything off of the intake on my 260Z and it did actually make a difference, and also filled the bin pretty well :classic:

I wouldn't worry about any bad effects from removing it as the engine is probably so worked passed standard spec that they wouldn't help smog anyway!

R.

[mandtw]

Thanks for your inputs on the smog. Is the PCV system required for efficient ops? I have been told that it removes gasses that could cause corrosion or oil break down.

[jcdozier]

It's been awhile since I lived in California, so I don't remember many of the details of the CARB regulations, but you may want to check them before you remove too much of the smog equipment. As I recall, older cars are exempt from smog inspection but I don't remember the cutoff date/age for the exemption. An '81 engine may still require "smogging" for registration renewal.

There was some discussion here related to this several months ago, so you might find something by searching the archives.

I have removed much of the smog "stuff" from my '71, but I no longer live in California. If your engine qualifies for the smog exemption, pulling off the smog junk may help it run a little better.

[zmanofwashingto]

First of all, all of that STUFF is neccessary for you to pass underhood smog inspections. If you don't have to worry about such things, then by all means remove the smog systems. You should leave the pcv system operational though. It does in fact, keep the engine from building up more gasses in the crankcase, and that system will rob zero horsepower or efficiency. The AB valve system, the egr system, and the smog pump system all 3, do in fact rob some hp and some gas mileage, but it's not very much. Almost completely unnoticeable, but still every little bit helps. You can also remove the water flow through the carbs, and the smaller water line that runs through the intake manifold. It's the one that taps off of the center/top of the tube that runs behind the engine from side to side. Note that on that particular tube there are 3 outlets all total, and the one that goes to the carbs is a threaded in fitting, and you can use a regular pipe plug to fill that hole. Be sure to plug off the lines that go into the air cleaner from the systems that you remove. Keep on z'in.

Z man of Washington

www.zspecialties.com

[John Coffey]

Keep the PCV system! A pressurized crankcase causes all kinds of problems (including reduced horsepower.) Run a line from your valve cover to the air filter and run a line from the block breather to the intake manifold WITH a PCV valve.

[owenk]

stranded in California City.

Hey I feel for you I grew up in EAFB & California City 61-73 . Great place for hauling arse and sliding sideways on dirt roads! It was strange when I moved away and found out that auto part stores are open on Saturdays and Sundays!

Curnnetly my connection to CalCity is my Brother and my mom's home which I manage as a rental.

Hey is Monti's Auto Wreckers still in Mojave?

Proud? product of Mojave HS class of 73