Making a Cool 1971 Alfa Spider  

 

            For quite some time now I have been on a search to find parts to add air conditioning (AC) on my 1971 Alfa Romeo Spider.  The hot and humid Alabama summer days make it virtually impossible to have top down during the day.  I use my Spider on a daily basis and the addition of AC only seemed to be a practical addition to enhance the driving experience.  Now for the big question, should I try to locate an AC unit from a later Spider or try to the junkyard route and design my own system?  You probably believe the junkyard route would probably be the cheapest way out!  It might be but the modifications that would have to be accomplished to make my 1971 Italian Stallion would have been astronomical.  I decided to search eBay for a complete system.  At first I found individual components, bid on a few but never won.   Finally I saw a complete system from a 1981 Alfa Romeo Spider.  After numerous emails with the seller I decided to bid and won the system for $99, a real bargain as it turned out.  I got two big boxes packed with all kinds of packing and miscellaneous hardware, some of which I scratched my head on for some time.

 

          I laid all the components out, cleaned them up.  I then assembled the complete system on my garage floor and tested each component to verify their condition.  As it turned out, each component appeared to be functioning properly.  If you seek advice from a professional about converting to R134A, you’ll probably get the run-around.  I’ve been told that when you convert to R134A the head pressure goes way up and it does.  This is my 3^rd or 4^th conversion and I haven’t had a single problem yet other than the outlet temperature is a little lower than the R12 system.  Could it be that the professionals don’t want us to convert to R134A because they’re the only ones that can get R12 and charge you a minimum of $200 just to charge your system.  I do have to agree on one respect that R12 is better for your older R12 designed AC system.

            Now the fun starts.  What follows are my installation steps.  You’ll want to check out each of the components for functionality.  Ensure that your compressor freely turns.  Then check out the evaporator fan by applying 12 volts to it.  Next assemble the complete AC system together and don’t forget to check all those sealing areas.  If you have a vacuum pump, evacuate the complete system until you have a good vacuum and record the number and close the vacuum supply valve.  Check to make sure the system is still holding a vacuum.  I usually wait overnight just to make sure.  If the vacuum has gone down you need to find the leak source and make the necessary repairs before final installation.

The next step you’ll want to take is in preparing the car for installation.  Remove the hood, battery, alternator and voltage regulator.   Drain and remove the radiator and front grille.  If you desire, you can also remove the front bumpers to give yourself a little added working space.   You’ll also need to remove the center console and side panels for the evaporator installation.

 

This next step will require a cutoff saw, chisel and a grinder.  Saw through the gusset that mounts the battery tray to the frame.  Once the gusset is off you can repeatedly bend the tray until it breaks at the spot welds.  Using a hammer and chisel or grinder, remove the rest of the battery tray.

 

I installed my battery in a battery box that I modified prior to placing it in the trunk.  Battery boxes that you purchase are too high for the trunk and must be cut down.

 

 Relocated battery in the trunk.

 

Run the new cables from the starter, alternator at this time, just make sure and leave the battery disconnected when you finish.  I used #4 wire.  I found the best place to run the wire into the trunk was to drill my hole just above the fuel pump and install a grommet for the wire to pass through.

 

            The double groove crank pulley I acquired was from a 2 liter and had to be modified due to the difference in timing marks.  Verify this on yours and re-stamp all timing marks if required.  Install your double groove pulley on the crankshaft.

 

Mount the alternator you plan on using in position.  I recommend using a 1977 GM 1500 pickup alternator available from your local parts store.  You can’t go wrong at a cost of $22 with a built in regulator.  Check out the alignment of the alternator with the back crankshaft pulley groove.  This can be done by using a 3/8” rod of sufficient length to contact both pulley grooves.  Place the rod on the crankshaft pulley and check the line up on the alternator pulley.  Measure any offset and record the measurement to achieve your final alignment.  If you are using the alternator that I recommend, you need to Machine the alternator and fabricate an adjustment bracket.  I machined the bottom leg of the alternator and open up the through hole where it mounts on the front engine housing.  I fabricated an adjustment bracket and mounted it to the AC bracket.

 

   

Milling the modifications to the alternator.

           Now that you have the alternator and crankshaft pulley aligned we come to the compressor alignment.  Install the compressor on the mounting bracket and mount the bracket to the engine.  Check the alignment of the idler adjustment and the compressor pulley using the same method we used for the alternator alignment.  Make any necessary adjustments as required for alignment.

 

View of the alternator placement.

            Now's a good time to make the alternator adjustment bracket and weld an attachment bracket that supports it on the compressor bracket.

            Install the condenser, electric fan and dryer.  All these components mount in front of the radiator making the installation quite a joy.

 

I wanted my original fan to be installed so I fabricated a spacer for additional clearance away from the fan belts.  I used a piece of aluminum and machined it as required to achieve the right spacing.

 

 

Fan spacer

 

Install the evaporator-I really can’t elaborate on this other than to say that I hope you have one that fits as well as mine did.

 

            Drill firewall ac hose penetrations.  I used a template so that the holes would end up in the right place.  Make sure and install grommets for the hoses to pass thru.  The template shown below, lines up with the metal stamping on the firewall.  Drill the correct size holes for your grommets.

 

 

Firewall drilling template

 

 

 Template placement

 

Remove fresh air boots from the dash vents and stuff them with foam or you can remove them altogether and plug the cowl holes.

Install the evaporator assembly, associated ducting and outlet hoses.

Route hoses to evaporator, drier, condenser and compressor through the holes in the firewall.   Route hoses so that they won’t rub on any sharp edges.  You’ll need to disconnect the compressor, and drier hoses for flushing, so leave these fittings only hand tight.  My evaporator to compressor hose routes from the evaporator through the firewall then along the firewall to the drivers’ side and up to the compressor.  The evaporator to dryer hose routes along the passengers side fender well and connects to the drier.  Run the rest of the hoses as appropriate.

 

   

Hose placement

 

Run electrical wiring.  All I can say about this step is that you need to locate a place for a relay that will control the compressor and electric fan.  I have my electric fan wired so it comes on with the compressor.  Run a fused 12 volt line from your starter (positive battery cable) to the common contact on the relay.  I used a driving light relay available from any auto parts store.  This way you’ll have the maximum amperage available for the compressor clutch and electric fan.

I also added an idle stop solenoid that activates when the AC is on.  This is available at your local auto parts supplier for around $24.   Wells part number E440.  I fabricated a mounting bracket to attach it to the intake manifold.

 

 

 Idle solenoid placement

Now that you have all the components installed, the system needs to be flushed.  I used AC flush available from my local auto parts store.   Follow the directions on the container.   Remove the hoses on the drier and compressor to make sure you don’t flush these components.  Pour AC flush into open end of one hose if you don’t have a flushing system.  Put other hose end in a proper container and introduce filtered shop air to the assembly.  Repeat this procedure until all hoses, condenser and evaporator are flushed.   

Connect a vacuum pump to the low side of the system and evacuate for 1 hour.  Evacuating the system is an important step in that it removes moisture that could damage the system through internal corrosion.

Charge system according to your conversion kit directions.  I used the kit that comes with the oil charge.  Install the oil charge then add the R134a.  I used a scale to measure the required R134A quantity.  Nobody could tell me the quantity of gas my system required so I calculated it and came up with 37 ounces.  Outlet temperature should be in the 40’s when the outside temperature is 72.  Mine is 38 degrees.  Remember that the converted system operates at 80%-90% efficiency compared to the original R12 system.

Update:

I decided to try *Enviro-Safe refrigerant and I am totally satisfied with the results.  The outlet temperature went from 40 with the R134A to 34 degrees F using Enviro-Safe, plus you get the added benefit of lower system pressures.

*This is not a paid endorsement for Enviro-Safe or the distributor.  It is only a reference to the source that I made my purchase of the product.