Air Conditioning Question

[halokilller]

Hello,

 

I just bought a 71 240z with a l28et swap in it. It appears that all of the a/c parts are in place but I cannot find a switch to turn them on. I read that some 240z's had a/c installed by dealers and others installed aftermarket kits. What are common places to look for an ac switch?

[BluDestiny]

My 260z had the AC installed by the PO, and he had a switch under the dash board. 

[halokilller]

thanks, will check under the dash

[psdenno]

Sometimes under the dash to the right of the steering wheel and sometimes attached to the side of the center console by your right knee - always within reach from the driver's seat, so there shouldn't be too many places to look unless it wasn't installed.  Are you sure the A/C was completely installed after the engine swap or was it "a work in progress" and none of the passenger compartment components are in place?

Dennis

[halokilller]

what passenger compartment components should I look out for?

[Pharaohabq]

You're probably going to have to trace wires.  The "Stock 240Z" AC parts are pretty obvious.

[halokilller]

Underneath my emergency flashers, there is rotary knob, this might be the ac control

[Milenko2121]

you could always just follow the wire from the compressor back to your firewall and see where it pops out.

 

Mine goes through firewall near my pedal, to a switch under my steering wheel.

Feels so ghetto, but hey, I got a car from the 70's with working R12 AC in the desert, so I do not complain.

[psdenno]

what passenger compartment components should I look out for?

 A/C hoses running from the compressor through the passenger side firewall to the evaporator and wiring for the control switch which could be a toggle and a rotary switch or just a rotary switch with a click on/off function.

[halokilller]

Im trying to trace the wire from the ac compressor but it goes into a big wire loom, will have to investigate further

[Tony D]

The "Stock 240Z" AC parts are pretty obvious.

 

Sad to say, unless you bought a RHD 240, you don't have a "STOCK" setup. AC was only stock on RHD models. 260Z and Later models had several options, FACTORY AIR, PORT INSTALLED AIR (both the same units) and DEALER or AFTERMARKET INSTALLED AIR the dealers could use the NISSAN kit, which was the same as the factory, or the port...or choose an aftermarket kits from ARA, Frigiking, or other vendors. The main difference was the Nissan kits had the evaporators IN the dashboard being pressurized by the blower fan, while aftermarket kits put the evaporator UNDER the dash on the suction side of the blower fan. In fact, any 260/280Z can have the Factory Air installed by following the directions in the FSM, which had a section specifically dedicated to the conversion. The majority of the arrangements came with pneumatic controls on these kits, though some retained the wire-operated controls and not the vacuum diaphragm controls. I'm not sure where those were installed (port or dealer.) I like the wire actuated units, same components as non AC cars, save for the faceplate and switch for the compressor being integrated in the faceplate. If you have a York Recip, but in-dash evaporator on a later car (260/280) chances are good you will have the wire actuated controls and someone was mixing and matching parts to make a system up. All the Nissan stuff used the Sanden Rotary Pump under the distributor.

 

Anything you have in a LHD 240Z Vehicle, you are dealing with 'aftermarket' A/C.  Depending on who installed it, and whether or not they followed the manufacturer's instructions placement of some stuff and vary quite a bit. Some aftermarket installers bodged the job pretty good, others it looks almost factory.

 

The passenger side components inside the car would be the evaporator assembly that hangs under the dash into the footwell area. I have seen the A/C switches utilizing the unused stock location rockers, the small ARA-Style pod by the driver's knee, a toggle in the center console or steering column surround, or one that looks like the Hazard Switch that goes in the 'blank' opening on the dashboard. Keep in mind the ARA and Frigi-King units both used adjustable capillary temperature switches to control compressor cycling by Evaporator Outlet Temperature. Over the years people can tweak those switches, originally they were set with a stop to block the Evaporator outlet temperature to 35/36 Degrees F so you don't turn it into a block of solid ice....which they WILL do if your compressor cycles too long. Watch your center register temperature, you should easily get 36F center register temperature with the setup. The key is to not have ANY air sucked around the Evaporator bypassing it's cooling, or sucking air past the uptake gasket from the cowl, letting hot air into the cooled airstream diluting the efficiency of the unit. 

 

Components in the engine bay are generally the same... compressor can be a York Reciprocating on a bracket that surrounds the fuel pump, or under the distributor with AIR Pump Relocation, or a Rotary in either location.

 

They aren't so bad if you get them set up right, with louvers on the hatch window, I was able to maintain 70 degrees in the cabin on a 103F day. I suspect if I had limo tint with proper UV rating, it would be even colder. The key to mine cooling so well was fixing those air bypass leaks. Center Register temperature dropped from 60's and low 70's to 35F. The gasket between to plastic housing to the fan inlet really was letting hot air in there---as that suction efficiency is lost, it doesn't pull air over the evaporator and it just doesn't cool worth beans! That's why factory AC's ALL use the fan pressurizing the evaporator into the cooling ducts.

 

Mixy-Matchy of the stock L28ET Sanden Rotary Pump will interface well with any aftermarket unit, you just need to get some proper lines fabbed at a local hose shop. I tend to like the hard lines used on the 260's/280's along with the stock condensor up front. That lets you use most of the later model engine bay stuff for a real finished look out there, and standard replacement parts... you then just need the conversion fittings to the hoses that go through the firewall into the evaporator under the dash. The stock ARA Switch and fuse setup will actuate the stock compressor clutch just fine. I've done countless units like this. A nice touch is you use the factory aluminum bracket for the compressor. If you are set on retaining the stock AIR setup, you will have to find the bracket from a 260Z with factory air, or any of the L4's with AC and AIR (I got one from a 79 510 Wagon, it's the same bracket...) 

 

Good Luck!

Edited July 18, 2013 by Tony D

[Pharaohabq]

We knew that there was no stock AC, Thus the Quotes around "Stock 240Z" as intended to refer to dealer option installations.  I'm sorry I should have been more clear.

 

Your information about the different AC pumps and about Leakage around the evaporator is certainly valuable. I would love to see some pictures of where you're talking about since I'm going to need to rebuild my 240Z AC (York) system, as well as hybridize the AC system in my 280Z-VQ swap. I want to use the 350Z compressor, but the rest of the parts would be 280Z.  upgraded to modern refridgerant. I know a lot of cleaning out of the old system and new hoses, oil etc would be required.  I do have the Sanden pump that was on the 280Z, I may move that to the 240Z if it's better, tho the York is much more "stock" :-b  The VQ uses a different Belt or I'd have kept the Sanden connected etc.  My 240 has the AC toggle right of the steering wheel screwed under the dash.

 

Early S30 AC systems seem to be a mystery, in that there seems to be a variety of different systems for the same cars. I guess it would be hard to identify them all, but similar parts such as the common York Compressors may be good to document.  I know the York compressors come in different sizes.  for RockCrawling we try to find the 12" throw compressors to use in On Board Air applications since those move more air for refilling large tires.  I haven't looked but I'd guess the S30 York application is either a 4" or a 6" throw compressor. I wonder if we put an oversized compressor on a S30, how well it would work? Faster cooling? maybe..  more freezing up, probably likely.  That's conjecture.  what matters is Identifying what components comprise the systems and detailing what could be hybridized with what other AC systems.  More information on the ARA and Frigiking setups would be awesome.

[Tony D]

There WAS, just not on LHD Cars.... 

The 69-73 RHD (S30) systems used the same Sanden on the 260 and 280Z's. The York is a US-Based conversion, it's stock on a Ford, but clearly aftermarket on a Nissan. The newer pumps have better efficiency. Really the pump from a Geo Metro is more than big enough to run the system in a Z....and about the size of the Z's AIR Pump! Nice compact little unit. It cycles "on" slightly longer, but that can be countered with a larger accumulator. The 'hit' you take when it comes on is less, obviously since it's a lower HP unit.

 

What you get with longer throw, you get more displacement at the same speed given same cylinder size. That means it takes more HP. The newer systems using rotary pump technology use smaller units that impact the HP drain on the engine less (hence Geo Metro) but run longer. As with any compressor the more capacitance (accumulator/receiver size) the SMALLER the compressor you can use for a given load.

 

A bigger compressor doesn't necessarily cool faster. You can only use so much coolant through the evap to cool it to 35 and then hold. So with the FO system, that's  pretty much set. You cycle the pump on and off to get the accumulator to a set pressure for feeding through the orifice at that given rate. A smaller compressor runs longer, but uses less power doing so. A bigger compressor sucks hp, and then shuts off. Your pressure switch or cutout based on temperature better be accurate or indeed you will overpresurize, over cool, and likely freeze up the AC Evap in the car. You are better going smaller on the pump. As long as it shuts off occasionally, it's big enough!

[halokilller]

Wow, great replies, thanks!

[jtz54]

Just picked up a '70 240Z with AC. Not sure if it's factory or not but the condensor and dryer are in the car and the compressor is missing. I want to put in a rotary compressor and use R134A. Any wirte ups on this and maybe a source of parts? Thanks!

[Trevor]

If you want to do it yourself,

here are some educational resources.....start reading:

 

http://www.ackits.com/

http://www.autoacforum.com/