Bobcat 320 with Mulcher

[Digdeep]

Lots of skidsteers have hi-flow, many with nearly identical flow, yet everyone talks about how one brand is better than the others. It is easy for a hydraulic pump to put out 37 or 38 gpm without any load on the pump or engine. Lets assume that a T320 and an RC100 are cutting an 8" tree. All of a sudden there is as big load on that cutters hydraulic motor. Remembering that flow (37 or 38 gpm) is "speed" and psi (3300 in this case) is "power" it makes sense that the engine with more torque (the engine powers the hyd. pump) will run the cutter head better because as the pressure increases (load on the cutter motor) and the flow starts to decrease (once again load on the cutter head) the extra engine torque allows the hydraulic pump to maintain maximum flow and pressure. Engines bog down under heavy hydraulic load, and an engine with higher torque won't bog down as quickly. Torque is what turns things under load, flywheels, hydrostatic systems, tires, tracks, etc.

 

[radman1]

Digdeep
What you say makes sense, if the engine bogs down with the hydraulics under load. I have a bobcat 873 about 71 hp (duetz engine) and standard flow. I can't tell any change in the engine at normal speed if the hydraulics are completely under load. I can certainly kill the engine however, if I am digging. Granted, the other machines are high flow and somewhat heavier but they also have 40-45% more hp. If high flow can bog the engine down under hydraulic load, then what you say would be correct. I don't have any experience with a high flow machine. The engine hp even in these larger machines with high flow well exceeds the hp from the hydraulic system. With mulching it would seem, nearly all of the available hp is for the hydraulics. A little hp is needed to slowly move the machine, run the a/c, move lift arms up/down etc...

 

[Digdeep]

radman1
You are correct, not only does the engine have to power the Aux. hiflow circuit for a mulcher, but it must also provide the power to drive the hydrostatic transmission, A/C compressor, etc.

 

[jmfox]

If a machine has hi and lo flow is it always better to go hi? I'm thinking of getting a lo flow brushcat to keep the vibration down but I don't want to significantly cut down the chopping ability.

jmf

 

[Digdeep]

jmfox
Just remember that flow=speed. Most of the rotary cutters rely on the "tip speed" and the centrifical force of the blades for their productivity. Faster tip speed= more productivity. Of course psi and engine hp and torque help to keep the tip speed high when cutting into thicker material. The swinging blades on rotary cutters also help to keep the hyd motor from slowing/bogging down when you get into thicker material too.

 

[Mowermoney]

Thanks for all the input, guys. Since my original post, I have had the chance to demo an ASV RC 100 with a Carbide Cutter generation 2. I'm sold. I was able to demo it on my job so that I could compare it to the Cats. The grind was mure complete with one pass. Felling speed was faster, less stuffing, and the ASV moror compartment was much cleaner after a run than any machine I've ever used. I have'nt heard back from the Bobcat salesman, but he would be wasting his time at this point.

 

[DirtyWorks]

ASV has 38gpm and 3300 psi...unless Dirtyworks wants to tell you his secrets...

99 Hydraulic Horses !! I'll take on your Bobcat T-whatever head to head anyday. Especially when mowing uphill with the A/C wide open. Let the little chips fly!

This post ment to be fun, informational, and in jest. No harm was done to actual bobcats during this filming.lol