Need log splitter cylinder

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Ashful

Minister of Fire
Mar 7, 2012
19,959
Philadelphia
Building a hotrod splitter, and can't find the cylinder I need. Clevis mount, 4" bore x 24" stroke with 3/4" ports. Excepting one trunion mount cylinder that comes up in my searches, all of the 4" cylinders I find have 1/2" ports, and all of the 3/4" port cylinders have 5" bores.

Any leads? What, no one wants to run 4" cylinders at 22 GPM? !!!
 
Thanks. I will check with them.
 
New cylinders are easy to disassemble. I guess you could always grind the fitting off, enlarge the opening, and weld on a new 3/4 fitting on the housing and reassemble and paint.
 
New cylinders are easy to disassemble. I guess you could always grind the fitting off, enlarge the opening, and weld on a new 3/4 fitting on the housing and reassemble and paint.
Yep. Just trying to minimize PITA factor, and I'm not 100% confident in my ability to weld a new fitting in without having to re-ream and hone the bore.
 
Yep. Just trying to minimize PITA factor, and I'm not 100% confident in my ability to weld a new fitting in without having to re-ream and hone the bore.
Weld the fitting from the outside and the inside will be smooth and clean. Cover the openings before welding.
 
I'm thinking I'd want to disassemble to do that. I'm wondering if the bore will go out of round, unless I heat it all 'round before welding the fitting.
 
I'm not sure what fitting you guys are talking about, but you can't machine it to accept a new fitting size?
These are the ports on the cylinder itself, which are currently 1/2" NPT, and need to be 3/4" NPT or equivalent for 22 GPM operation. Wall on existing bung is not thick enough to drill/tap for the larger thread size.
 
Yes, you would have to disassemble the piston first. You could have a shop change it out for you.
 
No need. I've rebuilt hydraulic cylinders in the past. I'm just trying to keep this project simple. If I can spend a few dollars on a new cylinder, to save a few hours of grinding, welding, and repainting, that's the way to go.
 
Interesting thought! Do you think I'd have to disassemble and get at the face of the end cap to enlarge the internal port there, too?

I really like the ergonomics of my clevis cylinder. They put the port at 45 degrees to the clevis, which puts the valve control at a real handy location. I'm going to see what Bailey quotes, but I'm leaning heavily toward just keeping my cylinder and limiting my upgrade to a 16 GPM pump. That will work with my existing 1/2" cylinder ports, tank ports, and valve.
 
-What shape is your existing cylinder? Is it worth modifying, or is it worn out or leaking or damaged rod?

-You could try SurplusCenter

-try a local hydr shop to weld on an SAE oring port at the 45 degree spot you want. They might have NPT.

-If you really like the 45 degree orientation, you won't likely find an off the shelf or surplus cylinder. Can you run a short hose or tube and mount the valve at the location you want?

-One off customs will be a LOT more money.

-Can you open up the hole in the tube? Sometimes they are not drilled as large as the fitting ID.

-If you really like the orientation, I'd run it as is and see what you get. 1/2 hole is not recommended, BUT, it won't affect the final forces at maximum pressure at all. It won't affect forces when the pump has unloaded to the low displacement/speed high pressure mode. In most case it won't affect the fast speed. It will increase the pressure drop to move the 22 gpm through the port, so when on high speed, that added pressure drop will cause it to reach unloading pressure and slow down sooner than you would like.
Pumps move oil by volume, and as long as it is below the unloading pressure it will still move at 22 gpm speed.
It WILL cause more heat as that pressure drop is converted to heat. However, if you don't hold the valve lever across relief and stall the cylinder, (i.e. You want to reduce the heat being generated across the relief valve) you might get by with the ports you have. More heat, more fuel, but it can run 140F easy, 160 F probably max. Most peope think 'hot' is when it feels hot, which can be 120 or less even.
I'd run it and see what the next step is first.
 
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Thanks, guys. In the end, the engine shaped my requirement, and negated the need for this cylinder. The GXV390 I'd want to run a 22 GPM pump is a little tall to fit on my current splitter carriage. So, in addition to cutting and welding ports on the tank, and cylinder, and upgrading all of the lines, valve, and cylinder, I'd also have to move the engine mounting plate. At some point, you just have to figure on building a whole new splitter.

So, for the interim, I'm going with a 16 GPM pump on a Briggs 21r707. This is an easy retrofit, as it will not require an upgrade to the tank, cylinder, or valves. I will simply need some larger lines, special fittings, and perhaps a larger hydro filter (still need to check that). This will give me an 8 second cycle time, not quite the 6 seconds I had originally targeted, but likely good enough.
 
Great decision!
Post some pics on how it came out please!
 
I will! Gotta find a local source for the engine, first. Don't want to deal with mailing it, on the off-chance something doesn't fit and I need to abort mission. Lowes and Home Depot both carry the engine, but not in the configuration I need: 21R707-0079-F1
 
Is there a local mower/saw repair place?
I got my engine thur such a place and it was defective , they took care of that as well!
 
That might be the route I have to go. Normally, I'd feel too bad returning something like a special-order engine to a mom-and-pop lawnmower shop, so I was hoping to find a big-box store that carried this model. But there is one local shop, who really screwed me bad on a Little Wonder leaf blower, where I swore I'd never shop again. Maybe they're a Brigg's vendor...