Quincy 325 help

[R_Holiday]

So I got a great deal on a Quincy qt-54 compressor with no motor. Got a nos marathon motor and added a magnetic starter. I recently was shooting the breeze and started reading about the 325 compressor. The itch hit and I went on marketplace and got one for what seemed like a fair price. I can’t tell the generation since it’s missing the label with the serial number. Compared to the vids I’ve watched it has some stuff going on that I don’t see in the vids by rotarycomptech. Here are some pics. Can anyone tell me if it’s just a newer model as the reason it looks so different or if someone just Frankensteined it to make it work? Also, how can I tell the ROC with no label if even possible?


https://www.garagejournal.com/forum/threads/quincy-325.541870/

 

[MacMcMacmac]

You can dump that long oil pressure pipe off the end of the pump and put a gage into the top port, or in the little elbow right on the end of the pump case.

The loose end of the airline on the top of the head near the flywheel goes to the top port of the hydraulic unloader valve on the side of the crankcase. The lower port on that valve gets connected directly to the tank.

The air pressure gage on the cylinder head unloader is mostly useless since it will only show pressure when the unloaders have been actuated at shutdown or if oil pressure drops.

The pressure gage in the front of the cylinder head is useful for troubleshooting valve problems, but if it shows a steady 40psi or so, remove it and put in a 60psi relief valve.

The tube with the rubber end on it is just a vent line for the air being exhausted by the unloader. You can toss that, or plumb it into a 1/4" NPT port in the top of the head right over the LP inlet valve if it has one.

The ****** sticking out of the inspection cover is a mystery to me. It looks like some sort of homebrew mod.

Some say the ROC is stamped into the end if the crankshaft, but I have never seen it, and would be irrelevant if the crank had been swapped out.

 

[R_Holiday]

Thanks Mac for all the info. I got it most apart. Having some trouble getting the connecting rod caps off at the moment. I’ll probably just start fresh with all the piping since it seems to need new setups anyway. Check out the pics. It looks like it’s been rebuilt before and inside the crankcase looks pretty good. 16 is stamped on the end of the crank so I’m gonna just run with a ROC of 16 for it. Hopefully the crank wasn’t replaced with the prior rebuild. The ****** on the inspection cover was definitely added. I’m assuming it was just for venting. The ****** is a quick connect so who knows.

 

[MacMcMacmac]

Yes, the end caps are snug. The best technique for me was to tap the rod bolts up through the cap.

 

[R_Holiday]

Yes, the end caps are snug. The best technique for me was to tap the rod bolts up through the cap.

I’m gonna try that when next I get up mess with it

 

[R_Holiday]

Yes, the end caps are snug. The best technique for me was to tap the rod bolts up through the cap.

Got the caps off. I’m no expert but I think the cylinders look good, pistons look good, and crank journals look good. Got a full tune up kit coming also.