S30 Vintage Air Gen II Mini Retrofit

[Dat73z]

Starting a Vintage Air Gen II Mini install thread.

 

Specifically this is going into my HybridZ, a 1973 240z which is a triple carb blowthrough turbocharged L running a FMIC, oil cooler, and retaining the stock hood springs and front valence. Factory dash, radio, and gauge mounting. Nissan Versa EPS. Wizard cooling AL rad with dual Spal fans. The same concepts would apply for any Z install, but packaging considerations may differ. 

 

Each post will focus on a specific aspect so hopefully it'll be easier to digest for the DIYer. I'll attempt to edit and add more details over time. 

 

Controls:

 

What I found researching is most either discard their OEM controls, or perform a partial retrofit where some OE levers are used, OE lever throws may be incorrect, and it seems everyone modifies their OE housing to accept an aftermarket blower switch. I wanted retain the full look and feel of the OEM HVAC controls including the OE blower switch and levers + lever throws. 

 

It's important to note that the Vintage Air unit I selected uses 4 switches. I also included the Vintage Air part #'s used as applicable: 

 

1. Fan (Off, Low, Med, High) - Rotary (OEM Switch Used) 

 

2. AC Thermostat (Off -> Cold) - Linear (11088-VUT)

 

3. Heater Temp (Off -> Hot) - Linear (11212-SUA)

 

4. Mode (Defrost, Upper Vents, Lower Vents, Upper/Lower Bi-Level) - Linear (11430-VUS)

 

For functionality and less to remember in the car what I'm going for is when all levers are to the right AC Thermostat is Off, heater is Hot, Vents are Upper/Lower Bi-Level. When all levers are to the left AC Thermostat is On, heater is Off, Vents are Defrost. So basically all left Cold, all right Hot. Note that the wires on the Mode switch can easily be moved around for any custom order of control, but it's important to get the mounting orientation of the AC Thermostat (bimetal thermostat) and Heater (potentiometer) correct to where you want them. 

 

I used 1/16" AL and SS tig wire for the linkage rods. For the Mode select I added 2 detent positions for a total of 4 including the factory 2 (chamfer the new holes a bit where the bearing rides for positive engagement and smooth disengagement). For the AC Thermostat I added an overtravel stop on the left/off position as I noticed even the OE lever would overtravel and crack the hvac control panel on almost every panel I've inspected so consider that an improvement over stock 50 years later 😆. 

 

For the bracketry I used some Home Depot scrap AL L stock I had left over from my wife's garden. I'll get those dimensions later. 

 

In the videos everything is dry with no grease so while things are already smooth with no binding they will get much better on final assembly. My plan is to black zinc coat everything but the issue I am having now is finding someone local in the Bay Area CA who will do zinc black chromate for larger parts. So perhaps I will run it patina as I'd rather not paint and have the sliding/friction areas gum up the grease. 

 

Pictures attached detail the arrangement, clearances, and function. 

Edited December 4, 2024 by Dat73z

[Dat73z]

Fan Switch:

 

I've mapped out the wiring and what I found was the vintage air switch has 5 terminals: 12v power, Fan L, Fan M, Fan H, and 12v switched only with Fan on to AC thermostat switch then onto the compressor clutch. 

 

The OE blower switch for my 73 at least has 6 terminals: Black (probably former ground) which is switched with Fan L, Fan M, Fan H, and a Red (formerly Blower 12v) + Blue wire (I believe unused in OE harness but for AC power) which is switched only with Fan on. 

 

So to go from 5 wire vintage air to 6 wire OE, I would split the vintage air 12v relayed switch power between the OE switch Black and Red wires (to power the fan and kick on the compressor clutch only when Fan on). 

 

Will update with better wiring drawing later unless someone else wants to help out. 

[Dat73z]

Center Vent:

 

Nowadays you can 3d print anything, but I wanted to use what I had on hand. And what I had on hand was scrap AL plate and 2.5" intercooler tubing. 

 

I tig welded the two components together and flattened the flange with a sanding block due to minor warpage from welding. Note that I found it's better to weld the plate to the tubing first before cutting the hole due to warpage. 

 

Edited December 3, 2024 by Dat73z

[Dat73z]

Compressor: 

 

For the compressor I'm using a Sanden SD 508 Compressor Double V-groove pulley Standard Finish (04808-VUA). Nowadays you can also get an electric compressor and mount it anywhere, but I decided to stay mechanical. 

 

There are dozens of Sanden SD 508 compressor configurations you can order, including rear fitting exits, and even custom machined rear caps. I especially liked the version where the charge ports for the high and low side were directly on the back plate but could not use that on my setup. I chose the standard top exit for packaging considerations as the turbo sits behind the compressor and I wanted to have the space directly behind to run a 4-5inch pipe from the turbo inlet turning down to the steering rack/front swaybar area of the splash pan to pick up cooler filtered air from under the engine bay. 

 

The compressor itself can be clocked, and the rear plate can be removed and clocked as well if needed so long as the centerline of the oil fill bolt does not exceed the 9:00 or 3:00 positions. I chose to clock around 9:00 to clear my intercooler charge piping and new ignition coil location. 

 

The mounting bracket is a ZSM Custom unit (a very quality piece, thanks to Zach) which I modified by milling the slots further to push the compressor back to clear my dual spals and engage the first row of the compressor dual row pulley (mating to Rebello spec BHJ dual row damper on F54 block). I have conveyed this information to ZSM Custom as well for future brackets. There are also several other bracket and fabrication options available but I decided not to go with any of those. 

 

I'll get some updated photos up of the final configuration later. 

 

 

 

 

Edited December 4, 2024 by Dat73z

[Dat73z]

Heater Lines:

 

For the heater lines I evaluated several options including AN, HS-79, and other fitting types. Ultimately I wanted more of an OE spec aesthetic so I purchased the following bulkhead fittings from Vintage Air: 

 

O-Ring Bulkhead Heater Fittings For 5/8 Inch Hose - Straight NO 10 Hose Fitting (34215-VUG)

 

90-Degree O-Ring Heater Fitting for 5/8-Inch Hose (121018)

 

I decided to run the OEM 240z heater hoses cut at the firewall and found that the bulkhead fittings were just slightly too long. So I cut them back to the base of the second hose rib from the top and bead rolled the tube right below the 3rd hose rib from the top to securely grip the hose. 

 

When installed on the firewall it really gives an OE aesthetic, especially running the trimmed OEM hoses. 

 

More details to follow. 

 

Edited December 4, 2024 by Dat73z

[Dat73z]

Evaporator and Cabin Unit:

 

Write this up later out of time today. 

Edited December 4, 2024 by Dat73z

[Dat73z]

Condenser and Dryer:

 

Writeup in progress

 

For the condenser I went with a half size parallel flow unit, which are popular with modified imports such as evos with space constraints due to large forward facing turbos: 

 

12 X 14 Superflow R-134a Condenser

 

On my s30, I have a large Setrab oil cooler mounted next to the condenser and a large intercooler in front which dictated the size and configuration. 

 

Similar to my oil cooler I found that due to space constraints routing softline would be borderline kinking even with looping the hoses around due to how tight things are in the cowl section. Looping the hoses and/or running them across the engine bay would have worked but that configuration did not look good to me. I also wanted to run the dryer off the condenser, retain the factory hood hinges, springs, front grille so basically all of this just made things even tighter. 

 

I concluded the cleanest approach for the most compact form factor would be to hardline the condenser No8 and No6 lines to the dryer along with bulkheading the connections at the radiator support. 

 

I used the following parts from Vintage Air: 

 

07323-VUC Standard Painted Drier with Trinary Switch and Mounting Hardware x1

Vintage Air 366100 - Vintage Air ProLine TiteFit Fittings x1

Vintage Air 366101 - Vintage Air ProLine TiteFit Fittings x1

Vintage Air 382680-MBA - Vintage Air Streamline x1

Vintage Air 12513-VCD - Vintage Air U-Bend-Em Refrigerant Lines x2

Vintage Air 125741 - Vintage Air Replacement Air Conditioning Hard Lines x1

 

Note for the No8 lines you can probably get away with one but I ordered 2 as I couldn't find the PN for Female/Female ends. Also as with all hardline work make sure you measure what you actually need and make wire templates before ordering material. I typically always order more length of hardline than I need as it sucks to be short mid-project. 

 

For the bulkhead fitting I retained the Vintage Air connectors but fabricated my own bulkhead plate to bolt into the existing s30 radiator support holes. I also swapped the position of the No6 and No8 lines to meet the angular requirements of the hardlines and also the softlines seemed to have better angles on the other side of the bulkhead as well. 

 

For the condensor mounting, I opted to soft mount with my usual choice of scrap AL and 1/8" high temp silicone sheet. I basically copied the Setrab factory soft mount arrangement which I had also fabricated for my oil cooler. Adding more detail and pics here shortly...

 

For the hardlines I typically work with stainless so my tools are mostly stainless instrument benders. What this means is for the tools I have on hand and materials, is the minimum bend radii for SS in the wall thicknesses I use is larger than what is achievable for the AL tube I used which isn't ideal for such a tight area. I didn't want to go out and buy a bunch of new hardline tools just for marginally tighter AL bends so to work around this, I had to rely on changing directions with minimal bends to make the angles required to fit the space. 

 

Note: If you have the AC line flaring tools disregard below.

 

When working with stainless I typically do AN style flares, although I have done bubble and others as well. The typical workflow for hardlining is to create the bends, then slip on the tube sleeve/nuts, then flare the connections. However, for the AL AC line apparently the flares are done on some large proprietary hydraulic machines. I did find what looked like a similar style of flare from Mastercool (not 100% on this and it was only the female side of some fuel push lock fitting) but the tool was like $500.

 

So I decided to use the pre-flared straight Vintage Air AL lines, bent them to shape, sectioned to length, then tig welded them back together. This is typical practice for AC lines esp for field repairs, and pre-flared tubing end sections are also sold for this. I think you can also braze or solder them but I've never tried that. Tig welding them was interesting as it was like welding around the circumference of a pencil but they welded really clean/easy unlike old oily castings. I also used 1/16 4943 filler which flowed really nicely. Machine settings were 70amps, pedal control, max freq, min cleaning action, 1/16 e3 sharp tip, #6 gas lens, 12cfh argon, 0.5s pre flow, 5s post flow. 

Edited January 12 by Dat73z

[Dat73z]

Line Branches: 

 

Write this up later out of time today. 

Edited January 12 by Dat73z

[Dat73z]

Refrigerant Charge and Service: 

 

Write this up later out of time today. 

[Dat73z]

Wiring: 

 

Write this up later out of time today. 

Edited December 3, 2024 by Dat73z

[Dat73z]

Misc.:

 

Triple carb idle up solution

 

Set a bunch of placeholders going to keep this post as a catch all. Open to any suggestions on what else I should add as I am working on this through the winter. 

Edited December 3, 2024 by Dat73z

[Dat73z]

Reserving post

[Dat73z]

Reserving post 2

 

Also have a bunch more pictures and videos to upload. Not sure why but I keep getting upload errors so perhaps I'll focus on the written aspects first. 

[calZ]

Excellent work on the switches. I'm excited to see the rest. 

[Dat73z]

Thanks @calZ. Big fan of your work.