Some folks have asked on here about why the suction has to be up. As others have surmised, this is so any oil that makes it into the refrigerant circuit (from bypassing the rings) can return to the sump. As long as the compressor is oriented anywhere between straight up to 90° horizontal with the suction on top, the oil return port drilled to the front bearing will be at the bottom where the oil can drain back by gravity. It is perfectly feasible to reverse the valve plate and head as shown here, but that is not enough. You MUST plug the existing oil hole with a suitable sized set screw (with thread sealant), small cup plug, etc. The hole MUST be completely sealed, or you will end up pumping high discharge pressure into the crankcase and it will go BOOM! Keep in mind that for use as an air compressor, plugging the oil drainback hole is the only mod you need to do. You can run the compressor with the suction port on the bottom in a horizontal configuration as long as that port is plugged because it will prevent oil from the crankcase from dumping into the suction side, and in air compressor use you aren't sucking a refrigerant and oil mix into the suction, just clean oil-free air. I should also mention that less oil will go by the rings if the compressor is mounted vertically. If you are going to use the compressor for AC service you also must drill out the oil drain passage in the other side. Otherwise it will load up with oil until the crankcase runs dry and/or you slug the compressor with oil. If you don't have the tools, means, and/or knowledge to properly modify the compressor, then don't. Simply buy one with the suction on the proper side for your application. You can find them used, or buy a new one manufactured in the USA by T/CCI. Forget about the Chinese York clones. They aren't much cheaper than the American made units, and they aren't built very well.
So, the little vent hole going to the front main bearing, shown at the 5:57 marker, goes to the suction plenum, upward on a horizontally mounted compressor. My application is in a Ford car, mounted horizontally with the Suction port on top. Is this simply a balance / internal breather, or what is its function? It is opposite from the dowel pin orientation, so I suppose it has a designated position to be in, either up or down. Have you any input on this question. I haven't been able to find any manufacturer info on this matter..... Thank You....RooDog....
I believe it is a drain for the oil that would be flowing through the system. As far as i know, it goes down through the main bearing and into the sump. I also know, that regardless of orientation, if you're using it for an air compressor, you can tap and plug that hole and see no ill effect and even possibly a reduction of the amount of oil that ends up in the discharge.
Not 100% sure. All the stuff with on board air states so. If you feel like experimenting, put the suction side down and see if it blows less oil. Reprt back
@@bcouri1 Int the York service manual, tccimfg.com/wp-content/uploads/2016/08/TCCI-SM-8.5x11-2014-12-16P.pdf it is stated several times that he suction should be up. Perhaps it has something to do with the communication passage going from the suction plenum to the front main bearing..... I don't know how that functions in the role of a simple air pump, but some users plug said passage with a set screw. Seems the way to go to me..... ....RooDog....
