Rotation of air compressor

Bobg

Also, is the pulley cast with an angle to the spokes, like fan blades, designed to blow air over the compressor?

As far as the amount of air it will pump, capacity SHOULD be the same in either direction.

This is only true of single stage pumps be it 1 or more cylinders, a 2-stage compresser is sensitive to rotation as the charge from the low pressure stage is timed to arrive to the high-pressure stage during its piston down stroke. I made this mistake on my 1947 Ingersoll-Rand 3 HP compresser by replacing the motor and not verifying the rotation. Mine does have an oil pump as well and I ended up scoring out the high pressure cylinder as not only did it not receive oil it was also bucking the incoming pressure charge putting thrust on the wrong side of the piston.
It cost me $75 for the repair on a compresser I paid $20.00 for from an old time body shop, the tank insides were like brand new however as I pulled the 1 1/2 side plug off and looked. Also got the "automatic" water release dated 1947 and still works!

Hows your tank? If in doubt check it out on the inside!

Brandon