Hydraulic pump identification

[bc]

Hello guys. Bot a couple Chinese mini excavators which I'm posting about over in the crawlers and loaders topic.

The ff13 has a standard pump attached to the 13.5 briggs and stratton engine. The ff15r pump has an additional component added on the end but there aren't any lines attached to it so I don't think it could be a second pump. Will post pics below with the ff13 first. Thanks.

 

[moresmoke]

Looks like a double section pump. Can’t see if there are two lines on the back side. Not uncommon to have the suction port connected internally to both sections. If not, I wouldn’t put it past the Chinese to have both inlet and outlet internally ported together just to make a larger pump with common parts.

 

[bc]

Looks like a double section pump. Can’t see if there are two lines on the back side. Not uncommon to have the suction port connected internally to both sections. If not, I wouldn’t put it past the Chinese to have both inlet and outlet internally ported together just to make a larger pump with common parts.

Just one line in and one out.

 

[bc]

Been researching and I am guessing this is a two stage pump.

Question is does the extra stage translate into more digging power such as when pulling back on the dipper/stick with the bucket in the ground? Both have the same size engine.

 

[wp6529]

If it's a two stage pump as used on log splitters it means faster movement when under lighter load and the ability to shift to the second stage and produce more pressure i.e. digging power at a lower speed when needed. Something I'd consider a good feature on a smaller low HP machine.

 

[bc]

If it's a two stage pump as used on log splitters it means faster movement when under lighter load and the ability to shift to the second stage and produce more pressure i.e. digging power at a lower speed when needed. Something I'd consider a good feature on a smaller low HP machine.

Ok. When I start testing and comparing the machines to see which one I want to keep and which one to sell, I will see how they dig. One video I saw suggested to idle back the motor when using the tracks to move around to avoid the jerky movement.

The better pump is on the yellow excavator with no cab. If I wanted to swap them out, which I may do, I would have to cut a hole in the ff13 side panel so the pump would stick out a few inches. Tradeoffs are that the ff13 cab with fan is noisier than the open ff15r and the ff15r may dig a little deeper because of how the boom is mounted on the front. Another tradeoff is that the FF15R has joysticks on the seat by the armrests and the Ff13 has the joysticks in front next to the track control levers. Both have a pedal to operate the front blade and the other pedal would run an auxiliary such as hydraulic thumb or post hole auger.

I am looking for an auger to go with either one.

 

[wp6529]

I would definitely stick with the yellow one. I really like piloted joystick controls (have them on my backhoe). I wouldn't want a cab on that small a machine, too clostraphobic.

 

[Dusty MI]

I've got a towable backhoe. It's got a 13" bucket, and a 4' reach.
Nice for small jobs.

 

[bc]

Looked again. That is a double section pump as there was an outlet from each pump. Didn't trace them but it makes sense that one runs the tracks and blade. The other one would run the hoe.

Took them both out and dug holes in the garden. Both run kinda herky jerky. Operator learning curve is a big factor. Too muddy to do much.

 

[bc]

I would definitely stick with the yellow one. I really like piloted joystick controls (have them on my backhoe). I wouldn't want a cab on that small a machine, too clostraphobic.

Too early to tell for me. My arms are just above me thighs on the 13. Cab is very loud.

 

[bc]

Hydraulic pump question. I'm not sure of the pumps these machines have but if I wanted to do an upgrade, which of these 2 stage log splitter type pumps from Surplus Center would work with the 3600 rpm at full throttle briggs and stratton 13.5 hp engine? I'm not sure what size shaft the engine has.

Some things such as moving around and light digging would be done throttled down but goal would be more digging power with the hoe. A couple holes dug so far found they stall out with the relief valve kicking in with the bucket pointed down in the clay and pulling back on the boom or dipper/stick.

Thanks.

Surplus Center pumps

 

[BarnyardEngineering]

You need to know what you have before you throw money at upgrades. What you buy may be a downgrade.

There's a formula that uses GPM and PSI to determine HP, but you have to keep in mind that the real HP output of that "13.5HP" engine is nowhere near 13.5HP, and your calculations will result in real HP requirements.

HP = (PSI x GPM) / 1714

Working backwards, 13.5HP can only supply about 11.5GPM at 2000PSI. This is all under perfect conditions, the engine being able to produce its rated output, 100% efficiency. All "log splitter" theory.

Now that I've written it out, I'm thinking it's highly unlikely that you're going to realize any appreciable gains from a "bigger" pump.

Engine shaft is probably 1", but it's not relevant because the pump is coupled to the engine with a lovejoy style coupler.

 

[bc]

You need to know what you have before you throw money at upgrades. What you buy may be a downgrade.

There's a formula that uses GPM and PSI to determine HP, but you have to keep in mind that the real HP output of that "13.5HP" engine is nowhere near 13.5HP, and your calculations will result in real HP requirements.

HP = (PSI x GPM) / 1714

Working backwards, 13.5HP can only supply about 11.5GPM at 2000PSI. This is all under perfect conditions, the engine being able to produce its rated output, 100% efficiency. All "log splitter" theory.

Now that I've written it out, I'm thinking it's highly unlikely that you're going to realize any appreciable gains from a "bigger" pump.

Engine shaft is probably 1", but it's not relevant because the pump is coupled to the engine with a lovejoy style coupler.

Ok. I read something earlier about decreasing the volume to make things work better at max engine rpm. Maybe getting more pressure with less volume?

So you are saying putting a 16 gpm pump won't help (assuming it likely has one with less than half that)?

Have to put a pressure gauge on it tomorrow and see what it reads.

 

[bc]

Went to the Perplexty app which is a great AI app for asking technical questions. Here is what I found for pump sizing and about a 30 gpm pump.

To determine the largest hydraulic pump compatible with a 13.5-horsepower engine, use the formula: HP=GPM×PSI×0.0007. For a 13.5 HP engine:

• At 2,500 PSI: GPM=13.5x2,500×0.0007≈7.7 GPM.
• 
  
• At 3,000 PSI: GPM=13.5x3,000×0.0007≈6.4 GPM

This means the pump should output around 6–8 GPM depending on the pressure setting. Pumps exceeding this flow rate may overload the engine.


No, a 13.5-horsepower engine cannot power a hydraulic pump with a flow rate of 30 GPM at typical operating pressures. Using the formula: HP=PSI×GPM÷1714.

• At 2,500 PSI: HP=2500×30÷1714≈43.7  HP.
• 
  
• At 3,000 PSI: HP=3000×30÷1714≈52.5 HP.

This far exceeds the available 13.5 HP, meaning the engine would be overloaded and unable to drive the pump effectively.