Kellogg 331TV Compressor Pump Issues

[pierre]

My latest craigslist find... mated with a true 5hp Dayton 1725rpm motor.

Acting a bit weird. It will steadily pump to 100-120 psi, then bog down to the point where the centrifuge unloader pulses off and on.

The belts are shot but still holding. I marked a line across them and the pulley. After running you can obviously tell they slipped, but it doesn't make any squealing noises.

It is geared to run slow... the pump's pulley is 18", motor is 5"... that makes it run at 480rpm. I wonder if it just needs more rpm's to get higher psi. I don't think its the motor straining - the current draw is about expected, measured at 17amps with a Fluke clamp on meter.

Also, while it's running, if you unscrew the oil fill cap you can feel obvious pulses coming from the crankcase. That can't be normal, is it? I didn't see a crankcase vent evident anywhere. There's a 1/4" copper line from the high pressure discharge side of the head to the unloader, but a separate line from the back of the head to what I think is the crankcase. Maybe a different kind of vent system I haven't seen before.

 

[454ragtop]

Might have a valve problem, just had to service the valves on mine a couple months ago. Thread here http://www.garagejournal.com/forum/showthread.php?t=333731

 

[pierre]

Thanks for the link. Can you feel any air / pulses on your pump from the oil fill hole with the cap off?

 

[Burgerkong]

Yeah the high pressure stage isn't working, probably valves.

 

[pierre]

Valves I can handle.... The pulsing crankcase air has me worried about something more serious.

 

[redmondjp]

Valves I can handle.... The pulsing crankcase air has me worried about something more serious.

This is perfectly normal - where does all of that air go inside the crankcase when the pistons are going up and down?

 

[pierre]

Good point, I guess I just never noticed it on the car engines I've worked on. It's probably much more obvious when the crank case is that small. Still unsure how that crankcase vent system works.

I got new belts on it - yay, no more slow down. Who would have guessed that was a failure mode for worn belts.

 

[AJ1978]

Did you ever resolve your issues with the pumping? Do not speed up this unit, it will run through the thick and thin at it's specified RPMS. These are great machines. I know a facility that can rebuild your head. This is one machine they are very familiar with.