Thank you for your question.
I can understand your concern with the air compressor not being able to keep up with the spray gun.
Most air compressor is rated for SCFM at 90 PSI and at 40 PSI. The SCFM at 90 PSI being smaller than it is at 40 PSI.
The average twin cylinder belt drive 60 gallon air compressor will produce about 12.4 CFM at 40 PSI and 10.2 at 90 PSI. It will also depend on the size and voltage of the motor. To increase out they may go up in horse power and turn the compressor faster to create more CFM.
I cannot see the manual for this model, so I cannot see what the output is. It seems to be quite old of an air compressor and it may no longer be producing like it once did.
I am surprised that your HVLP gun takes that much volume. My one quart HVLP spray gun only requires 7.0 CFM at 40 PSI or less.
I hope this information will help.
Thank you for using Manage My Life.