Automotive Air Conditioning Information Forum

I think it would also be useful to get the temp of the pipe going into the cond and the pipe out.
Also, we need to know if the larger pipe goes into the top or the bottom of the cond.

We understand that you are frustrated. Most of us are from TX, NV, AZ, SC. DetroitAC works in the industry.
We ask lots of questions because we can't see or touch your system from our keyboards

well, currently using a red orfice tube which is between the blue and orange. It made little to no difference over the white.

started out with 36oz of r134 and it was undercharged. inlet and outlet temperatures were 10 degrees apart. At 48oz the inlet and outlet tube on the evaporator is within 3 degrees but the low side pressure is 51 at idle and 45 to 48 at 2000 rpms. It is probably over charged by couple of oz ATM, but that is not enough to make up 10 degrees or more inside the cabin.

As far as compressors, the ones you mentioned would require cutting out part of the cross member to fit. That is why i mounted it on top instead of the bottom. I can get mounting brackets for an R4 or the Sanden. That is it as far as i know. As far as pully ratios, the crank is stock ls2 and the Sanden is the stock 6 rib. They only sell the compressors with the one and getting a custom pully for the crank is not going to make a difference. Spinning the compressor a little slower or faster is the same as letting up on the throttle or giving it more. Neither is going to get me 10 degrees. And it is not a race engine. If it ever does more than 4500 rpms it will be by accident.

I may be trying to mix apples and oranges with the compressor and the rest of the system. But i would need to be confident an R4 will get me where i need to be before i waste 200 on a compressor, 220 on mounting brackets, 30 dollars on flush and another 50 bucks for R134.

at this point it looks like replacing the system with a vintage air system is the best option over spending another 500 bucks on a guess. It is a known performer, even as fragile as it is. But i don't give those plastic encased tiny little studs a month before they pull out. Maybe i will do it right before i sell it.

AC pros, y'all are talking, but......

which Sanden comes with the VA setup.....

DetroitAC wrote: ↑Tue Jun 28, 2022 2:28 pm There is a lot going on here, I haven't read it all but here's what I see.

Sanden 508 is a small compressor, 138cc which is tiny compared to say current production Tahoe 200cc.

Depending on which LS you've swapped in there are some really great compressors that will bolt right on. If it's an iron block truck LS, I'd choose a Denso 10S20 or something like that. LS1 came with Delphi v7, also great for a swapped setup.

How's your drive ratio to the Sanden? Measure the ratio of engine crank pulley diameter to compressor pulley diameter.

YOU HAVE NO IDEA HOW MUCH CHARGE THIS BLAZER NEEDS. You replaced almost everything, most of the charge when operating is in the condenser which you changed and the liquid line.

My feeling is that you have it overcharged. You have very little cooling going on, but high condenser pressures.

Determining charge on a CCOT system takes some patience. White OT is one of the biggest and you have a tiny capacity system at the moment. Start on the low end of sizes, maybe orange or blue. You operate at high blower, engine 1500 to 2000 hold it there, start undercharged but a reasonable amount. Add charge 1oz at a time, add more each time if you are way off. Evap out pipe will be warm and inlet cold when you are undercharged. When the evap out pipe is same temp as inlet, add about 4 to 8 Oz more. Record low side pressure, high side, ambient, vent temp.

I wouldn't waste time with that Sanden. Yes it was made in Texas, but I'd go for 200cc Denso

Informative!

tbirdtbird wrote: ↑Tue Jun 28, 2022 2:54 pm I think it would also be useful to get the temp of the pipe going into the cond and the pipe out.
Also, we need to know if the larger pipe goes into the top or the bottom of the cond.

We understand that you are frustrated. Most of us are from TX, NV, AZ, SC. DetroitAC works in the industry.
We ask lots of questions because we can't see or touch your system from our keyboards

Larger tube is on top and goes to the high side of compressor. Smaller one is on bottom and goes to the OT and then into the evaporator.

Temp of pipe in and out of condenser was also requested.
We are asking for standard diagnostic info, else we are just guessing....

hi
Sanden 7H15 common conversion compressor is 154.9cc = 9.45 cuin ,,,,, oil capacity 130--200ml pending model

Sanden SD508 compressor size 138cc = 8.4 cuin

Delco R4 comp size 164cc=10 cuin . oil cap 170cc