Quincy PTO driven air compressor

[Mattman]

Hey tanker yankers, what is the rpm at which a Quincy 4cylinder PTO driven air compressor needs to run at? There is very little information about these compressors.

Trying to get the rpm so that I will know what speed PTO I need for the transmission.

[Rawze]

if they had any brains, they would run them at 1650 or 1750 rpm but we know better.. most them are made for less than 1000 rpm like the complete morons who design such systems that know nothing about engines would design.


(the whisky is talkin tonite' .. just a warning.)

[Pigpen 2869]

When I worked at QC we ran them around 1100 rpm. If u are going to be using them on a daily basis and possibly several loads a day the Drum compressor is a better choice. Alot more money but they pump up a tank alot faster.

[Mattman]

The PTO determines the speed at which something turns. And there is several like more than 10 different speed PTO's.

Yes sir the drum type is way more expensive than the one I am getting for free.

I just have to come up with a PTO and PTO shaft parts.

[Pigpen 2869]

I ran a 100% one and bumpped up the rpms. Alot less vibration than the guys that ran the 130% ones. Spend the money on tubular shafts instead of the solid ones they hold up alot better

[Mattman]

Pigpen the PTO shafts that I will be using are the 1 1/8 hex. I have access to these shafts and yokes at little to no charge.

I had figured my PTO at the 135% or there about. What you said about vibration noise does make sense. I may need to re figure to the 100% PTO. I know some PTO shaft driven liquid pumps have around a 900rpm limit for engine speed with PTO engaged.

I wanted to go the hydraulic PTO route, but the cost got to the not feasible point very quick.
Probably only air off 1 to 2 loads per week. So not used much. The reason I could use a compressor is because the added time to unload with truck air is the difference between making it home and a 10 hour break within aight of the house. Also with plenty of air pressure/volume helps to clear a 3 inch hose of product.

[Rawze]

(07-10-2021 )Mattman Wrote:  ...
I know some PTO shaft driven liquid pumps have around a 900rpm limit for engine speed with PTO engaged.
...

that low rpm driving hydraulics under any kind of moderate loads is exactly why those typical car hauler trucks have such shortened engine life... just something to consider.

[Pigpen 2869]

Those solid shafts are heavy. Slip joints and u-joints do not last very long. Keep spares with you. The hydraulic setup is the cats ass but gets expensive.