22 or 28 gpm pump?

[Isaac Carlson]

I am getting a 22 hp v-twin for the splitter and I need to choose a pump.
It is running a 4 inch cylinder and I want fast times without over-pumping the splitter.
I currently have 1/2" lines on it. I have looked at several charts for flow ratings and 1/2" is on the very bottom end for 28 gpm, but would it work without getting too hot?

 

[blades]

You are going to need to increase those line sizes with either pump as well as the valve if not at least 3/4" now. Using the 1/2 lines is going to cause a lot of heat, marginal preformance upgrade with the big pumps. Here is the real kicker -Likely that your cylinder only has 1/2" ports save some bucks going with 16gpm or have the ports on the cylinder redone to 3/4 or 1"( best). Its all about how fast you can fill& drain the cylinder. It would be possible to build a 11gpm unit that is faster than your proposal.

 

[Isaac Carlson]

The valve is rated for 30 gpm and has 3/4" through ports and 1/2" working ports.
I have bored the cylinder ports. I called Cross Mfg. today and one of their engineers said that the 28 gpm pump would be fine with the valve I have as long as the pressure and return lines on the valve are 3/4". He said the working lines would be fine at 1/2" as long as the fittings flow well.
I am currently using a cyclone style tank that I built some time ago and it is working very well at ~16 gpm. The size I am using is supposed to work up to about 40 or 50 gpm.
I have no problem putting a cooler on the return line if needed. I would not be running the pump at much over 2/3 throttle anyway.

 

[kennyp2339]

I'm real interested in this, I know more about tying my shoes than hydro's though so I will just be in the background absorbing the info

 

[Isaac Carlson]

This is not going to be a "this week" project. It will be more of a "try to get it done by mid summer" project. I brought the motor home today. It feels pretty good and I need to rewire the solenoid since the previous owner did it backwards and it needs a tank of gas and a new battery. I cranked it over with my jumper box and it sounded nice and smooth with decent compression. It is supposed to rain here tonight so it will have to wait until tomorrow to get unloaded.

 

[Jags]

After proving to myself that 3/8" ports on a cylinder can handle everything a 16gpm pump can push through it with little to no side effect, I would say that my real world experience would leave me to believe that a 28 gpm pump isn't gonna cause major issues with 1/2" work ports (I agree, returns should be increased to 3/4").
I actually did several tests and runs with the 3/8" ports on a 16 gpm pump with pressure gauges and IR thermos. Virtually zero pressure build up because of the ports and the fluid temps showed no signs of excessive temps when compared to my other splitter using the same pump with larger cylinder ports. YMMV but it wouldn't scare me in the least to run a 28 gpm pump as you describe.
Gonna be crazy fast cycle times, though.

 

[JA600L]

The heat is mostly generated in the pump not the cylinder or hoses. Running a cooler on the return line is always a good addition to get the reservoir temperature lower. Overheating the pump is a primary concern.