Added the compressor and Delco alternator
While waiting for the Hurricane unit to arrive, I decided to work on the installation of the compressor and alternator. I ordered the same Sanden type compressor from Nostalgic Air that LarryC used in his stock AC upgrade. It comes with a double pulley unlike the stock FI unit that has a single. I also ordered the stock AC water pump and the double pulley that goes with it. I also ordered the stock AC compressor mounting bracket that attaches to the block in place of the alternator bracket as well as the compressor mounting plates and bolts to connect the compressor to the bracket. I also got the stock alternator upper bracket for an AC FI car that connects to the cam box since the non-AC one is attached to the original water pump. I got the double pulley and shims that replaces the single pulley on the crankshaft, but I was able to work out a solution using only two V-belts instead of the three that the stock system uses so I will be returning that. Thanks to Matt at MWB for providing all of the used items and a new water pump.
I got the idea for the two belt set-up from LarryC, since his ’79 stock AC system only comes with a two belt arrangement as well as from Dennisrh, who posted on his thread about moving his AC system from his totaled Bertone to a non-AC one and only used two belts. Larry’s ’79 is carbureted so that uses a different water pump than the FI AC cars. From what I can tell, it positions the water pump pulley in a different plane than the FI cars, plus the compressor mounting plates and the upper alternator bracket are different as well in a carbureted car.
Here is the compressor bracket and water pump mounted, then the compressor mounting plates.
On top of this, I wanted to fit a Delco-Remy 12SI 78 amp alternator instead of the Bosch one. I saw the recent thread from old mech (
http://xwebforums.com/forum/index.php?threads/25810/) who did this on an AC FI car by using a hacksaw to modify the bottom mount on the alternator and then fabricated a custom upper adjusting bracket from ½” steel. I don’t weld, but I can cut, grind and drill, however, the thought of trying to hacksaw out a bracket from ½” steel did not sound like fun, plus I did not want to hack up my alternator case. If you ever need a new one, you have to return the exact same one to avoid the core charge. Granted it is not much, but still…. As Tony stated, if you get stuck and need a new one, it is much simpler to just bolt in the replacement. I wanted to figure out a way to mount it intact. Plus, I only wanted to use two belts so I was not tied to trying to make it fit the stock mount.
I initially tried to do this with the engine in the car, but that was not going well with the limited access. The engine was going to come out anyway for the car to go to the body shop in a few months so I had to detour for a few days to drop the engine. Much better! Of course, as I played with the arrangement, I would hoist the engine back into the car to make sure the alternator position cleared the sheet metal. I was frankly amazed that the mod that old mech did with the custom upper bracket actually fit in the car without hitting the top alternator mount on the rear of the engine compartment. Since the Delco alternator has the mounts at 12 and 6 o’clock, when you mount the alternator to the water pump as the stock is, it tilts the alternator rearward and positions the top mount towards the rear of the car, hence the need for the long curved custom bracket.
My first step was to mount the AC compressor with all of the stock brackets. As it turns out, the outer pulley of the new compressor lines up perfectly with the stock single crank pulley. Of course, it would also line up with the inside pulley of the double crank pulley so this compressor would be a bolt in replacement for the stock one. I wanted to run the second belt from the inside pulley of the compressor to the water pump and alternator like Larry’s ‘79, but the water pump pulley as mounted in a FI car has the outer pulley lined up with the outer crank pulley and the inner pulley lines up with the stock alternator pulley. I found that if I turned the pulley around and mounted it inside out, it moves the whole pulley inboard so that the outer pulley groove lines up with the crank pulley and outside compressor pulley groove, and the inside pulley groove lines up with the inside compressor pulley. There is a seat machined on both sides of the water pump pulley that fits perfectly over the water pump impeller mounting plate either way so Fiat must have designed it like that for a reason. From what I can surmise, this is how it is mounted on the carbureted AC cars. The clearance between the inner edge of the pulley and the snail engine mount is very small, but there. You have to take off the pulley to put the belt on. This is actually much easier with the pulley inside out because there is much more clearance to the passenger side of the engine compartment.
The other thing I found is that the timing bracket on the non-AC cars is different than the AC version. It has a slot cut out of it to clear the belt going to the compressor, plus it sticks out further to line up with the timing mark on the outer crank pulley. Dennis’s install ran the belt from the crank to the compressor and the water pump and by doing that, it clears the timing bracket. I PM’d Dennis to see how his two belt set up has been working and he said fine for the past year and a half. The only issue is he has to keep that belt pretty tight to avoid squealing from the belt. I surmise that this is because there is only about 90 degrees of wrap of the belt on the water pump so that has to drive both the pump and the alternator without slipping. I was planning on running one belt from the crankshaft pulley to the compressor and the second from the compressor to the water pump and the alternator so I had to cut a slot out of the timing bracket to allow clearance for the belt.
I decided to mount the bottom foot of the alternator to one of the upper mounting points on the compressor, which is how Larry’s X is. For the pulley side of the mount, I modified a bracket that was part of a conversion bracket set that I found on eBay for converting from a generator to a Delco alternator. I originally thought I might be able to use that to mount the alternator to the stock water pump mount, but it took up too much room. I took one of the pieces of that set and modified it with my trusty hacksaw and drill. One could make the same thing out of a piece of ¼” steel, but since it was mostly the right size and I had it, that’s what I did. As it turns out, when I mounted the alternator to the compressor like that, the fronts of the cases line up and the pulley of the alternator is perfectly aligned with the inside pulley grooves of the water pump and compressor. The gods were smiling on me that day.
When I first bought the 12SI alternator at auto parts store, I did not know which one to get and the gals behind the desk had no idea what a 12SI or 10SI was. I have read the thread about using a 10SI from a ’78 350 Camaro, but I wanted the 12SI due to the better cooling and electronics. The gals were very indulgent and after a couple of attempts, I got what I wanted by specifying a 1986 V-8. I wasn’t sure how I wanted the clocking of the outputs, but the one I got had the outputs at 9 o’clock. Once I started playing with it, I realized that would put the outputs right next to the exhaust manifold. At first, I thought I would have to go back and get one with them at 12 or 3 o’clock, but as I looked at the alternator, it looked pretty symmetrical to me. I took out the four bolts holding the case halves together and apart it came. It turns out, that you can turn the back to any of the four positions you want and then it bolts right back together. If you take it apart as I did, the brushes pop out, so you have to put those back in to put it together. There is a small access hole in the back to insert a small screwdriver to hold the brushes in place while you put it back together. For future reference, just remove the bolts, and twist the two halves to how you want it clocked.
It seemed like using just one bracket on the front would put a lot of torque on the bolt and mount when the belt was tightened so I wanted to have a second bracket at the rear of the bottom alternator foot. The stock alternator to water pump mounting was not far away and very substantial so I looked at that as a mounting point. I needed a curved bracket to clear the alternator case and leave room to pivot the alternator when changing the belt. I was looking at the new stock alternator bracket that I had acquired and noted that the curved portion end was the perfect curve I was looking for. I wouldn’t be using either the bottom bracket hole or the hole with the braised on nut for tightening the upper adjusting mount point on the stock alternator, so all I needed of it was the part with the hoisting ring and a place to drill a hole for a new upper adjusting arm.
Here are pictures the bracket that I made for the pulley end of the alternator as well as of the stock bracket next to the one I cut up to make two brackets for my needs. The lower curved piece fits nicely between the water pump mounting point and the lower alternator bolt. I cut down a ½” spacer to correct for the offset between the water pump and the alternator foot. I could have used a bunch of washers, but I this looks cleaner to me. For the upper adjustment, I found a nice 2.5” stainless adjustable Heim joint rod on eBay for $39.95. I drilled a hole in the upper bracket and mounted it so that it was close to parallel with the V-belt. I used an M10x100 mm bolt for the bottom alternator mount and an M10x70 mm for the mount to the water pump.
Now it was off to the auto parts store to get some V-belts. After some trial and error, I found two that worked well. The outer crank-compressor belt is a 10x840 mm and the compressor-WP-alternator belt is a 10x802 mm. Here it all is outside and inside the car. I think it should work well, but it will be next summer some time before (hopefully), it all gets put back together and actually fire it up. If anyone sees something I have overlooked, please chime in. I could not have done this without all of the ideas from Forum members.