Removin smog from -73 240z

[Reverend]

My friend decieded he wont need the hidious smog thingy in his car and asked for my help. He has "euro" balance tube and wants to put it on place. It sure does look much better without, i used to have "euro" tube when i had SU's.

 

SO, the difference is huge, compared to -72 smog equipment (plus this is automatic). Tons of hoses and stuff. Are those two water pipes necessarry, can we plug them? We live in northern Finland so temperature wont be an issue here...

 

Basically, can we just strip all the stuff out?

 

 

[Stanley]

The water pipes are the supply and return for the manifold heater system, that circulates hot coolant through the intake manifold to warm it up in cold weather. It's supposed to have a hot = closed thermostat (so it shuts off when the engine warms up) between the rear of the intake manifold and the metal tube that goes around the rear of the engine, maybe it's there but I don't see it. It's probably good to have in cold weather. Problem with it is the tube that goes through the manifold gets rusty and leaks.

 

The air galley, that rusty pipe that connects to each runner on the exhaust manifold is the most difficult piece to deal with. Mine was leaking exhaust fumes everywhere, had it removed and the holes in the manifold welded up. There are other, more technical solutions that are nicer, search the site - there are photos of how others have done it.

 

The metal tube that's hooked to a tee (other side goes to the brake booster) is attached to the AT modulator on the transmission (with a crappy old 2" rubber hose that needs to be replaced if not done already, otherwise it will fall off and you'll think the tranny is shot). The AT won't work right without it.

 

The rest of those antiques can be trashed in my opinion, no place for them on the Euro balance tube anyway. What is all that stuff?

[Reverend]

You tell me How about the dual points distributor, can it be run correctly without the smog equipment? I've heard its only on automatic transmission models

[Reverend]

Just found out that i have asked these questions earlier too. We decieded to postpone the project till now.

 

http://www.classiczcars.com/topic/50267-removing-smog-need-assistance/?hl=smog

[Stanley]

You don't want that dual point distributor, expect hard starting, reduced performance, and an insanely difficult process to set dwell and timing. Easiest is use '70-72 new (from Japan) or rebuilt single-point, Euro-spec distributor. Single- point emission spec OK I guess. Or go electronic.

[Reverend]

So can we take off the second set of points and drive like that? I've started to dismantle all that smog crap, 2 green wires from the distributor goes into it. My friend says the car occasionally just stops and wont start till you wait a moment and try again.

 

Im afraid we do something irreversible if we deciede to hustle with the dizzy. He wants to have the car ready to drive as soon as possible... :/

[Stanley]

Doubt if removing one set of points would work but I don't know. Why not just order a rebuilt single point for a 70-72? It's about $100 USD. A-1 Cardone part 31-607 for the US spec., but if you get one from your local auto parts store I'd think it would be the Euro spec. model. A new Hitachi Euro spec from Japan costs $650 USD here, so if you get a rebuilt one and it's Euro spec please post the information. Maybe Nissan dealer in Europe can get you new factory one.

Edited June 10, 2015 by Stanley

[Reverend]

My friend just wants to get this Z running quickly. He also has stock 260z distributor, would that work?

[beermanpete]

Removing one set of points should be fine as only on set is used at a time. You need to remove the "retarded" points and retain the normal points. Also, there is a temperature sensor and perhaps some other control circuitry that selects which points to use. You might as well remove that stuff as well.

[Reverend]

We removed all the smog and installed 260z single point distributor. We have to block the weird pipe going to exhaust manifold from balance tube, it snapped just from the root and we cannot get it out...

[beermanpete]

We removed all the smog and installed 260z single point distributor. We have to block the weird pipe going to exhaust manifold from balance tube, it snapped just from the root and we cannot get it out...

 

It sounds like the EGR port. We plugged the EGR port on our 73 using a pipe plug. I don't recall the exact size but it is close enough to the correct size to tap for a 1/2" or 3/4" pipe plug without drilling larger first. If you cannot remove the existing fitting drill it out and tap for a pipe plug. See photo below.

 

The later manifolds use a differnt fitting and it is not quite so convenient. Fortunately, our later manifold was in good condition so I made solid plug to replace the pipe and ferrule. I used the original nut to hold the plug in. Sorry I don't have a photo of that.

[Reverend]

You don't want that dual point distributor, expect hard starting, reduced performance, and an insanely difficult process to set dwell and timing. Easiest is use '70-72 new (from Japan) or rebuilt single-point, Euro-spec distributor. Single- point emission spec OK I guess. Or go electronic.

 

We tried with single point distributor. It gave spark but just did not start, not even tried. Then we decieded "what the heck" and try with the dual points distributor. Starts right up, like a nanosecond after you turn the key and revs nicely. I dont know how this is possible as you stated it wont start and timing is impossible to find. We did excatly that, timing is now @ around 17 degrees and idles very smoothly..