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General Discussion / Re: 20 years
« Last post by 78 Chevyrado on August 01, 2026, 11:55:42 pm »Today: A/C cools good enough at idle to make the windows sweat like a coke can. It'll freeze you out on max going down the freeway.
https://www.youtube.com/watch?v=ejjaXG5cwa4
I did the Sanden swap on the compressor. Buy whatever kit you like to mount a Sanden Compressor to your SBC. First two cheap off brand compressors died within months. Got a real Sanden and HD unit #4618HD. Got to learn how things work and why and read all the specs of everything. In short, more capacity than the usual recommended Sandens. Get a REAL Sanden that has a GV head cover on the back. A GV head will connect to the stock lines on a (my only experience) 78 Chevy C20. I assume it will connect the same to any C-series that has the original big Harrison A6. Had to shorten the hard line to the condenser about an inch so I cut the line and put an inline filter there. Did that not because I needed the filter, just because it was the easiest way to shorten the stock line with seals compatible with the Refrigerant and Oils. Other change was to use a ford expansion valve PN#F5XZ-19D990-AB. Got that R-134 system way closer than it ever was to R-12 cooling levels with the old Harrison compressor.
I always use Chemours R-134a with zero additives. I only use Chemours because I know they don't cheap out and add stuff we don't need. Those self sealing cans work great. Got one I last used 4 years ago and it hasn't lost any gas since then.
Alternator is a Mechman 170 amp Racing alternator for 63-85 GM - Natural Finish It costs a lot initially, but it costs less than buying cheap repops over n over again.
For the pulley set on it. get the pulleys off of an 87 TBI truck or some earlier TPI Camaros. I only got this idea because I had an 87 V8 truck and it had this odd pulley set. The pulleys are exactly the same as normal v belt pulleys EXCEPT the alternator belt is a 5 rib serpentine. Makes all the difference if you need more than stock charging.
I bought the underdrive set because they are machined properly. the stock stamped set I had before was way out of round and that made the alternator jump all around and act weird. after I got this set I don't notice any less on the power steering, but the ac only makes the engine drop less than 100rpm vs stock the ac made the engine drop almost 200rpm at idle.
https://www.youtube.com/watch?v=ejjaXG5cwa4
I did the Sanden swap on the compressor. Buy whatever kit you like to mount a Sanden Compressor to your SBC. First two cheap off brand compressors died within months. Got a real Sanden and HD unit #4618HD. Got to learn how things work and why and read all the specs of everything. In short, more capacity than the usual recommended Sandens. Get a REAL Sanden that has a GV head cover on the back. A GV head will connect to the stock lines on a (my only experience) 78 Chevy C20. I assume it will connect the same to any C-series that has the original big Harrison A6. Had to shorten the hard line to the condenser about an inch so I cut the line and put an inline filter there. Did that not because I needed the filter, just because it was the easiest way to shorten the stock line with seals compatible with the Refrigerant and Oils. Other change was to use a ford expansion valve PN#F5XZ-19D990-AB. Got that R-134 system way closer than it ever was to R-12 cooling levels with the old Harrison compressor.
I always use Chemours R-134a with zero additives. I only use Chemours because I know they don't cheap out and add stuff we don't need. Those self sealing cans work great. Got one I last used 4 years ago and it hasn't lost any gas since then.
Alternator is a Mechman 170 amp Racing alternator for 63-85 GM - Natural Finish It costs a lot initially, but it costs less than buying cheap repops over n over again.
For the pulley set on it. get the pulleys off of an 87 TBI truck or some earlier TPI Camaros. I only got this idea because I had an 87 V8 truck and it had this odd pulley set. The pulleys are exactly the same as normal v belt pulleys EXCEPT the alternator belt is a 5 rib serpentine. Makes all the difference if you need more than stock charging.
I bought the underdrive set because they are machined properly. the stock stamped set I had before was way out of round and that made the alternator jump all around and act weird. after I got this set I don't notice any less on the power steering, but the ac only makes the engine drop less than 100rpm vs stock the ac made the engine drop almost 200rpm at idle.
