Designing A/C System Using Other Cars Parts?

[HusseinHolland]

Finished the compressor mount . Tacked in place

[HusseinHolland]

Worked on the AC lines from evaporator to firewall, sealing the box, and sealing the ductwork to the box. Fitted the dash frame to check all fitments 

have to crimp the fittings 

sealing foam for lines exiting the box

closed cell foam to seal box to frame attachment

test fitted evaporator box & dash frame

gap around duct housing

Even worse on the right

added a flange to mate with the Nissan duct, so I could seal the gap. Factory evaporator box must be taller & narrower.

extra thin foam on top half, due to angle of evaporator box

Added thick foam to the duct, to seal against the flange

 

then added thin foam to seal the facia vent to the duct

sealed now

Edited August 18, 2023 by HusseinHolland

[HusseinHolland]

Touched up the silver edging 

Test fitted the compressor & mount. It will have to be raised age least an inch. Rear lower mount sits on PS rack. Stock Datsun AC belt length will be OK (13x875). 

Have to figure out the best place to drill through for a harness for the AC stuff

Edited August 23, 2023 by HusseinHolland

[HusseinHolland]

reworked the mount plate, set all holes 1.5" below original; had to add an ear for the rear lower mount point. 

back in place, with earth strap for compressor

compressor in place. Belt could be 25mm shorter, but still have enough range as it is

belt alignment and clearance all around looks good

With that aspect done, I worked on the condenser mounting & high pressure hose fitting. Low press hose will be shorter

made standoffs (set 1.5" off the bulkhead) to secure the condenser, one with 3 M4 screws on the right, 2 separate ones one the left; upper with one screw, lower with two.

about an inch along the top. I will make seals to fill the space along the top, and down the sides of the condenser. 

rolled the lip in the bulkhead to make sure the high side line doesn't chafe

[Matthew Abate]

On 8/22/2023 at 9:57 PM, HusseinHolland said:

Have to figure out the best place to drill through for a harness for the AC stuff

@gotham22 posted photos of some places where things for the AC go through the firewall on my build thread if that helps.

https://www.classiczcars.com/forums/topic/51541-1973-rebuild/?do=findComment&comment=645520&_rid=30168

You should only need one wire, though, that goes from the AC thermostat switch to the pressure switch and then to the compressor.

Edited August 24, 2023 by Matthew Abate

[HusseinHolland]

1 hour ago, Matthew Abate said:

@gotham22 posted photos of some places where things for the AC go through the firewall on my build thread if that helps.

https://www.classiczcars.com/forums/topic/51541-1973-rebuild/?do=findComment&comment=645520&_rid=30168

You should only need one wire, though, that goes from the AC thermostat switch to the pressure switch and then to the compressor.

Hello Matthew - Loved the bracketed you worked up for your HVAC install, very clean work!

Couldn't see any pics with wiring, but that's OK. In my case it's not one wire as with the original setup, as there is also a Trinary switch added that is used for high press cutoff. I didn't mention it, however I'm also adding a Volvo (Bosch) Constant idle speed system they used back in the 80's with K-Jet V6 applications, prior to using Bosch LH2.xx systems. That requires approx 11 wires to pass from the cabin to the intake.

[Matthew Abate]

Thanks for the compliments!

That’s interesting about the constant idle system. I’m assuming that plugs into an ECU? I’m running Mikunis and a ZX distributor so don’t have a computer to control. I’m thinking of rigging up an adjustable servo actuator triggered by the compressor that would interfere with the throttle lever to raise the idle when the AC is on, but I haven’t thought it through yet.

I’ve integrated all of my AC wiring into my engine harness, which I am rebuilding now. Here’s the thread: 

 

[Patcon]

5 hours ago, Matthew Abate said:

Thanks for the compliments!

That’s interesting about the constant idle system. I’m assuming that plugs into an ECU? I’m running Mikunis and a ZX distributor so don’t have a computer to control. I’m thinking of rigging up an adjustable servo actuator triggered by the compressor that would interfere with the throttle lever to raise the idle when the AC is on, but I haven’t thought it through yet.

I’ve integrated all of my AC wiring into my engine harness, which I am rebuilding now. Here’s the thread: 

 

That sounds like the way the idle up was handled on some older cars in the day. When the compressor was energized it triggered a relay that actuated a solenoid that push on the throttle linkage enough to idle it up a couple 100 RPM's

[Matthew Abate]

Exactly. The only reason I’m not 100% sure I’m going to do that is that I don’t know where I will put the servo. Otherwise it’s pretty simple.

[HusseinHolland]

11 hours ago, Matthew Abate said:

Thanks for the compliments!

That’s interesting about the constant idle system. I’m assuming that plugs into an ECU? I’m running Mikunis and a ZX distributor so don’t have a computer to control. I’m thinking of rigging up an adjustable servo actuator triggered by the compressor that would interfere with the throttle lever to raise the idle when the AC is on, but I haven’t thought it through yet.

I’ve integrated all of my AC wiring into my engine harness, which I am rebuilding now. Here’s the thread: 

 

I'll take a deeper look through your thread, looks like you are going whole hog on that!

[HusseinHolland]

Much rain today, so only small amounts accomplished

First, I had to deal with the upper left rad mount. With the AC high side line placed directly in front of the bolt, there would be no access for rad removal without discharging the AC. Not a good plan, pretty much guaranteeing Murphy's Law will strike. So, I drilled out the rad fixed nut, and added an M8 rivnut to the bulkhead, so that one bolt is accessed from the bay. Did mean I had to remove a bunch of stuff to get the rivnut tool in there.

Figured out the condenser to rad sealing. Foam on the verticals, rubber seal along the horizontal lip.

Had enough of a window to prep, prime & then later paint the nose panel, before I get everything back together. 

After that I worked on mounting the AC fan to the condenser. I previously used 2 of these on my X1/9, they don't flow the claimed CFM, however it's enough for this purpose, and this will also go away with the V6 conversion anyhow. Added M5 rivnuts to secure the fan. Had to add an additional plate to make it work.

added waterproof AMP/TE connector, 2.3mm terminals 

also wired the Trinary switch, used a Sumitomo 4 pole connector here

 

Edited August 25, 2023 by HusseinHolland

[HusseinHolland]

Still plugging away at the AC components.

Condenser in, High side attached, made the #8 compressor line next

I made sure the AC service equipment could attach to the line fitting, there is plenty of clearance off the heat shields 

Before I did the low side to the compressor, I took care of the old PCVC hose. Volvo PCV hose for a 740 has the correct end ID's - just not the correct offset of the 90º ends, so I cut it in half & re-oriented it. Clamped after confirming fit was good (not shown)

then I made the low side hose from accumulator to compressor, has a 90º splice fitting to keep routing clean

added another M5 rivnut to the heart shield to add a support clamp for the new line

Had to add a second retain screw for the bulkhead fitting, so it would stay put when tightening the AC hose fittigns

Just have to finish cleaning the heater box, then I can install the evaporator & draw down the system to vaccum test. Still have to wire the system & condenser fan circuit

Edited August 27, 2023 by HusseinHolland