Automotive Air Conditioning Information Forum

Probably oil and refrigerant release onto exhaust manifold from PRV pressure relief valva due to overcharge of oil and/or refrigerant.
hotrodac

Highly likely they're mufflers. I have one on my car's suction line and it's supposed to keep the reed valve noise from reaching the evaporator. Fails miserably, in my case. Here's a pic.

SD7 had discharge reed noise due to oil stiction with flutter caused by BOURNELLI effect (lowering pressure ...

Some of Your techanical comments are basically applicable to variable displacement compressor optimization and have little to do with fixed displacement comps or evaporator capacity.
Evaporator fin density is a function of evaporator air velocity, suck verses blow through evap, , heat transfer ...

Compressor built in mini oil separator can be rendered ineffective by wear particles plugging the oil return hole which would increase oil circulation throughout the system but only very minor effect on cooling. An indicator of compressor wear is a dark grey lube color caused by aluminum fines ...

BIG ears,
Some cars have a heat shield between the back of the comp and the exhaust (Civic). You could try that.
Liquid refrigerant condenses in the coldest place in a static system. In your conditions that is the evaporator where lube also collects. The liquid storage receiver is probably in the ...

Excellent history report and references to comp and txv designs. Your BIG ears cause concerns that most people never consider. Hard to hit the nail on the head by remote analysis w/o pressures.
1) 2000 Tracker had a small Denso evap matched to a sanden SDB very small 87 cc fixed displacement comp ...

Vacuum = a lot to do about nothing.
Modern compressor dual shaft seals have a outer elastomer above atmosphere pressure lip seal and a inner teflon compounded under atmospheric pressure
seal. The inner seal is often scratched during sloppy or dirty service replacement (w/o a proper shaft seal ...

Love Key Largo and scuba diving john Pennekamp coral reef offshore.
The R-4 is too much displacement capacity for most Vintage Air A/Cs and avaliable condenser "real estate" space.
Early SD 5H14 (508) used SP 20 PAG which was exactly same as GM PAG 100 single end cap lube. PAG 46 (SP15) double end ...

We could use the a/c system's old high volumetric efficiency Borg Warner York ( with back seating valves) that was mounted on the engine to evacuate the system on the side of the road. These old Yorks could squirt R-12 out the head gasket during liquid slugging, BW increased top dead center ...

Vintage Air's book "How to Air Condition Your Hot Rod" explains how to match system component capacities so that the compressor capacity (displacement/swept volume and drive ratio) is not excessive.
condenser energy rejection must match the evaporator heat absorption plus horsepower energy draw of ...