Originally Posted by DUTCH MAX HEADWORK
I think that oil return line is important in both systems to remove oil from the bottom of the evaporator to prevent oil logging of the evap. On the POA eliminator each time the compressor stops the refrigerant has a chance to pool in the low spots, the evap being one of them. Too much oil here cuts down on EVAP efficiency.
When you start your recharge, charge by weight. When you get close to having a full charge watch your low pressure side. I think your best vent temps will now come in with about 30 psi or slightly less on the suction side. I can see adding the Schrader valve will improve vent temps a bit, but think you'll still see a slight drop off in performance at idle. We shall see.
For some reason, I thought you were running electric fans, but now I see you are running the stock fan set up. To me, that's a good thing. You should be running the 772 fan. Hayden makes a HD and severe duty fan clutch, these will come on sooner and also offer more flow at idle. Not 100% sure they are available for this application. The cost is more noise and less fuel efficiency. The payoff is more flow through the condenser at idle. Bob, Robinls5, is a big fan of the late model Suburban fan clutch. Personally I think your numbers are fine, but these parts are another step up to chase that Dragon you've been chasing.
I wish you would have asked about the Schrader valve before you removed it. It's been 10 years since I installed a POA eliminator kit, I'm trying hard to remember if it had the LP SCHRADER valve in the oil return line, I 'm pretty sure it did, but not 100% sure. If someone has one on a shelf maybe they can check it out for us???
Thanks Al, yes, I also wished I asked you about the LP Schrader valve...
Yes, I am running the original stock 7 blade curved fan with the Hayden heavy duty fan clutch, NOT the severe duty.
When I got back from travel, I was low on freon.... I found the leak, the low side schrader valve on the POA was leaking, and the cap would not hold it back. I got a new cap with an o-ring and it holds pressure and "pops off" when I unscrew it, but, it looks like I will have to monitor this low side schrader valve --- I am hoping it will fix itself now that I got the cap to hold pressure...
Well, everything is ready now - LP schrader valve, and I believe I have roughly 46 oz of so of freon... Here are my new numbers this morning. I started with a cold car, 85 degree garage - than went up past 90 degrees after 15 min.. I ran two house fans on the condenser, started the Chevelle and ran it from cold start for 15 min... Engine was at 1500 rpm. I like my numbers... What do you think ?
Low side, high side, center vent temp.
32, 125, 48 deg
31, 125, 45 deg
29.5, 133, 43 deg
28.75, 133, 43 deg
29, 140, 42 deg.
30.75, 156, 43 deg.
31.5, 167.5, 44 deg
32.5, 167.5, 44 deg.
32.5, 170, 45 deg.
32, 170, 45 deg.
34.5, 175, 47 deg.
The garage was about 95 deg. after all this... about 10-15 min. of running. I then knocked down the RPMs from 1500 to 950 RPM and let it settle for a few min. This is what I got:
Car warm after 10-15 min. of running:
Idle - 950 rpm, low side - 38, high side - 167.5, center vent temp - 49 deg..
I am thinking I am pretty close..., what do you think about my numbers and the freon quantity ? Thanks.