by Ed Esslinger in The August 1996 RootesReview
Several weeks ago while working on my newest S-IV Alpine the weather turned hot and humid. I began to wonder how difficult and how cheaply and air conditioner could be added.
I don’t recommend using used parts, unless you have the tools and experience to test, clean and purge the used units. As I have air conditioned two Tigers with good results, and have the tools, I felt I could go the cheap way.
The first step is to locate the parts. A trip to my local wrecking yard produced a Sanden SD 505 compressor and a 9 inch condenser fan from a 88 Chevy Sprint. The condenser would also fit (10” x 20″), but a defect in the mounting of the compressor on this car causes the discharge plumbing to ruin the compressor (I found this problem on two cars). The price for the compressor and fan was $30.
I still needed to find a small condenser that would fit in the front of the radiator. A trip to another wrecking yard found one and a small under-dash evaporator unit. Cost: $45.
I did the following to make the S-IV more reliable before I installed air:
- Changed the electrical system and the tach to negative ground.
- Changed the radiator core to a 3-core heavy duty type.
- Installed a 165 degree thermostat.
- Installed a Weber-type carb.
- Installed a Ford alternator and regulator.
- Relocated the brake servo to the same location as on a Tiger.
- Installed an electric fuel pump.
- Had an additional belt pulley welded to the water pump pulley.
- Fabricated and installed a fuel pump block-off plate.
- Fabricated compressor mounting brackets. The front compressor bracket mounts on the front engine mounting plate. The rear (compressor) bracket (mounts) to the fuel pump studs and to the upper right oil filter base.
Connecting the system is a standard setup. I added a pressure switch (not cheap $40) to turn on the condenser fan when needed. Could save this money by having the fan run all the time when the air is on. The compressor and the water pump are (both) driven by the crankshaft pulley while the alternator is driven by the additional water pump pulley. Watch for clearance of the fan belt under the water pump outlet and lower radiator hose.
This setup will cause the engine temp to run 10-to-20 degrees above what it was. At 95+ my car is running 190 degrees with no problems. Good luck and stay cool.