Log splitter Engine replacement?

[RobbieBones]

I have a old 25 ton Yard machine log splitter which needs a new engine. The original engine was a 6 horse G&S a friend gave me a 5 horse B&S from a lawn mower. The shaft sizes are differnet and I understand I would need to change the lovejoy coupling on both the pump and the engine.

It has an 11gpm pump.

Questions:

How much slower will it run with the 5 horse engine?

If I find a 8 or 9 horse engine how much faster will it run?

What would need to be modified with the larger engine besides the anchor points?

Thanks Rob

 

[dex3361]

Since you are likely keeping the same hydraulic pump the 5HP will have the same speed but have less ton capability. If you go with the bigger HP engines your speed will be the same (as the RPMs of all these engines are 3600RPM max) and give you more ton capability before stalling the engine.

 

[yankeerider]

Have you owned and used your splitter for a long time? Reason I ask is I have a 20 year old Duerr splitter (rated 20 ton, I think) I bought new that is powered by a 5 hp B&S that has never really met a log it couldn't split. When they don't want to split the wedge just slices through the wood until the cylinder reaches the end of its stroke.

Two years ago, the pump seized, but gradually enough that it merely stalled the engine. I replaced it with (I think) an 11 gpm pump, and added a hydraulic pressure gauge. That revealed that my splitter never spends any significant time above a couple hundred psi.

Remember, two stage splitter pumps automatically transfer to low volume/high psi at relatively low pressures. That means that, unloaded, engine hp doesn't make any difference in speed. Once the pressure builds, your splitter valve relief may well kick in before the engine is overloaded.

You should only need to change the engine half of your Lovejoy coupling if the rest of it is in okay shape. Why not try what you've got?

 

[RobbieBones]

After looking for a used engine at the local yard machine dealer, I will be staying with the 5 horse. I think I need to change both halves of the coupling because the coupling I need for the 5 horse shaft is LO-90 25mm bore, which is larger (total outside diameter) then the Lo-75 5/16 bore that is on the pump. Yes?

Rob

 

[oldnslo]

After looking for a used engine at the local yard machine dealer, I will be staying with the 5 horse. I think I need to change both halves of the coupling because the coupling I need for the 5 horse shaft is LO-90 25mm bore, which is larger (total outside diameter) then the Lo-75 5/16 bore that is on the pump. Yes?

Rob

Yes, in this case you will need both halves of the coupling and the insert or spyder that goes between them.

 

[yankeerider]

Yup, just as oldnslo said. You need to match coupling outside diameters. The LO-90 is rated for higher torque transmission than the LO-75. I ended up changing up to an LO-90 simply because the local TSC only had that size in stock, and my pump half had been damaged. Since you're going from a 6 hp down to a 5 hp engine, the LO-75 would be adequate, if you could find the engine half you need in the LO-75 size.

 

[GE222]

I don't believe you will notice a difference going from a 6hp to a 5 hp engine. One reason was mentioned above in that the engine really only works when under high load conditions, also how small engines are rated in terms of power has also changed. For example, trying to buy a small engine now that actually has a horsepower rating versus a displacement size rating.

 

[Pete Judd]

All these engines are designed to run at 3600 rpm. So no pump speed difference on "no load speed" you may find that it might be straining a little more under a hard load, but your old engine was doing that as well. I think that I might be a wash between the old and the new.

 

[felix1952]

to replace the motor of a log splitter is only 3 screws ?

 

[Willie B]

30 years ago I was poorer than now. I built a wood splitter,( in VT a log is 8' or longer), from a mix of mail ordered parts and salvaged. The frame was from an old mobile home, 2 layers welded together, the engine from a dead lawn tractor, a freon tank for oil, wheels from a Pinto someone left parked too long in the woods. I replaced bearings and rings, the engine ran OK but always leaked a minute amount of oil at the top of the crankshaft, this fouled the points. Each time I wanted to use it I had to take off the sheet metal, remove the flywheel etc. run a piece of paper through the points, and reassemble. It ran fine, if I needed it the next day I might have to do it again. This was getting old!
I resolved to replace the engine. A friend had a not very old mower with a bad transmission.Adding a gas tank, discovering the starter was dead, adding a recoil unit, needing 75.00 worth of head bolts because of the gas tank, then we mounted it. It ran! It ran well! I stepped up to the valve, pulled the lever, and discovered the muffler was blowing on my leg! It was about two inches away! I couldn't help but get burned!
My son's buddy came along, said Torrie bought a bunch of hydraulic pumps. He has some 30 GPM single stage PTO pumps. $150.00 later I had converted it to 3 point hitch. It works so much faster, quieter and more powerful than ever. I can lift or lower for comfort. It is a joy to use.