Log Splitter Pump Question

[robmunach]

I recently bought a used log splitter that was in a fire. It is an 8 HP, 32 Ton with a 5" cylinder and a Barnes pump. It appears to be fairly old. I replaced the hoses and the engine with a 5 1/2 HP Honda GX that I had laying around. I assumed that I would just have less pressure with this engine than with the 8 HP. 32 Tons is overkill anyway. I assume this is a two stage pump as the ram moves with reasonable speed. I do not know, however, if I am building enough pressure with this engine to get into the second stage of the pump. The engine will stall on large oak logs. There is a cap on on the pump that houses a spring and a ball - I assume this is either a relief valve or the valve that changes it to the second stage. If I cut some coils off the spring, will this lower my second stage cut-in pressure? I have heard that 650 psi is the standard setting which equates to about 5 hp required to hit the second stage assuming a 13 gpm pump (a guess).

Thanks,

Rob

 

[jd2305cd]

I am not sure, but if it works on all other logs then it maybe just undersized a bit. Cna you work it slowly and not stall the engine.. I know with mine when i get into the hard stuff i can just go slow at it and get through it. A lil forward, wait al lil forward wait. Luckily it only happens once in a while..

I built mine from scratch and used a 2hp electric motor. Its a high torque low rpm motor, only puts out about 1750 rpms. That 3 extra HP could really be making the difference, might be the right size for that pump anything smaller might not have enough ***..

 

[sizzami]

sounds to me like you have an issue with the relief on your valve it should not stall your engine if it cant push the pressure should bypass , but really that is a secondary issue to your power problem 5.5 hp should run 13gpm pump but is at the low end of range it is possible that the second stage of the pump has something broken and locked up so that when it tries to kick in it causes a dead head which would stall the engine I would tear the pump apart and see whats doing in there

 

[LD1]

a 13 gpm pump is pretty uncommon for a log splitter. They are usually 11gpm or 16 gpm. Given the 5" cyl I would guess a 16gpm pump is what you have.

I agree that you should never stall the engine. The bypass should open first. I have split some nasty stuff and had the wedge completly stop and not kill the engine(Huskee 27 ton 11gpm w/6.5 hp B&S)

The smaller engine may stall because it may not have the HP to make enough pressure to open the bypass, it depends on how the motor is rated (overrated/underrated). Since it's a honda you might be alright.

To figure the HP requirements ue the formula: (PSI x GPM)/(1714 x Efficiency)

If it is a 16gpm pump, the specs are 16gpm @ 650psi and 3.5gpm @2500psi (second stage) and 85% efficient

Which would require 7.13 HP to kick into second stage and 6.0HP to open bypass at the top end of second stage

If in the off chance it's a 11gpm pump (11gpm @ 650psi 2.9gpm @ 2500psi and 85% efficient)

You would only need 4.90HP to go to second stage adn 4.98HP to make full 2500psi on the second stage.

 

[Arkhermit]

I would check the pump out real good. You stated it had been in a fire, heat does wonderful things to springs and things. Something is probably stuck.