My old tractor had SS so shifting gears and clutching and going backwards was a PITA. My new one is hydrostatic, has a cab, and with more PTO HP than the front mount - it just flies through the snow now. It used to take me up to 2 hours to clean 3 driveways. Two weeks ago we had 8 inches of snow and I did 4 driveways in 45 minutes. Being warm and dry plus a shorter drive doesn't make going backwards as much of an issue any more!
Hydraulic Motor Sizing
- Thread starter Hilbilly
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My old tractor had SS so shifting gears and clutching and going backwards was a PITA. My new one is hydrostatic, has a cab, and with more PTO HP than the front mount - it just flies through the snow now. It used to take me up to 2 hours to clean 3 driveways. Two weeks ago we had 8 inches of snow and I did 4 driveways in 45 minutes. Being warm and dry plus a shorter drive doesn't make going backwards as much of an issue any more!
oldnslo
Super Member
The difference between men & boys is the size & price of their toys
If you are doing a chain drive make sure the motor you select has bearings rated for side loading.
It’s easier to get forgiveness than permission...
After some more reading and talking to the hydraulics guy at Princess Auto, I came with the best fit for my SS being a 6.1 cu in motor capable of handling 20 gpm and 2973 psi. According to my calc's this motor will produce 26 hp, 2887 in lbs of torque and run at 567 RPM. The bigger motors run at slower rpm's and still only produce 26 hp due to the limited flow of my SS.
I bought the motor and was going to install it with a sprocket drive system but opted for a direct drive, just in case the motor had an issue with side loading. I couldn't find a coupler to go from the 6 spline to the 1" motor shaft, so I made one using the weld on sprocket hubs I bought. I drilled some alignment holes in the 6 spline hub and the 1" hub, then made some pins to fit the holes, put them together and welded the perimeter.
Here is the coupler in progress.
Here is a pic of the temporary install. Had to give it a try.
It works, but not great. Pretty sure the lack of HP is the issue. It only throws snow about 20', maybe 25'. It also bogs down fairly easily. I think it will be ok for blowing snow to the same side of the driveway that I'm working on. Probably not for throwing it across the driveway and I'm not sure if it will work well with heavy snow. I'm going to make an SSQA mount for it anyways and then give it a go. If nothing else, I can use it for most snow blowing, just go a little slower. At least I can drive forwards. If I need more power I can still use it on the back on my tractor. The hydraulic motor and cross brace come off the blower by undoing 2 bolts and then I can put the driveshaft back on. Simple, easy swap.
I bought the motor and was going to install it with a sprocket drive system but opted for a direct drive, just in case the motor had an issue with side loading. I couldn't find a coupler to go from the 6 spline to the 1" motor shaft, so I made one using the weld on sprocket hubs I bought. I drilled some alignment holes in the 6 spline hub and the 1" hub, then made some pins to fit the holes, put them together and welded the perimeter.
Here is the coupler in progress.
Here is a pic of the temporary install. Had to give it a try.
It works, but not great. Pretty sure the lack of HP is the issue. It only throws snow about 20', maybe 25'. It also bogs down fairly easily. I think it will be ok for blowing snow to the same side of the driveway that I'm working on. Probably not for throwing it across the driveway and I'm not sure if it will work well with heavy snow. I'm going to make an SSQA mount for it anyways and then give it a go. If nothing else, I can use it for most snow blowing, just go a little slower. At least I can drive forwards. If I need more power I can still use it on the back on my tractor. The hydraulic motor and cross brace come off the blower by undoing 2 bolts and then I can put the driveshaft back on. Simple, easy swap.
Looks good.
Sounds like you might not be getting the flow/pressure you think at your engine RPM. You can try going to a smaller displacement hydraulic motor to get more PTO speed - PA is great at letting you returns stuff.
Is that an inline flow restrictor? Have you tried plumbing the motor direct without splitters or flow valves?
Sounds like you might not be getting the flow/pressure you think at your engine RPM. You can try going to a smaller displacement hydraulic motor to get more PTO speed - PA is great at letting you returns stuff.
Is that an inline flow restrictor? Have you tried plumbing the motor direct without splitters or flow valves?
That us a cross over relief valve, just in case I jam something in the blower. It is supposed to send the pressure spike back to the reservoir and hopefully protect the gearbox. I used an inline pressure gauge to set the relief valve at 2900 psi. The motor is only rated for max 2973 psi continuous pressure and the SS supposedly operates at 3000 psi. If I go to a smaller motor I will get less torque and I'm thinking this motor is a little on the weak side. Seems like I have to trade something off to improve something else. More speed means less torque. Less torque means go slower. I hear you about PA. They are great to deal with. I think I need more flow but can't get it from this machine. i'm also thinking that the long 1/2" hoses may not be big enough and are too small. That will result in higher pressure losses but not sure if that would make a big difference for such a short run. I also set the pressure close to the motor. So that may not make any difference.
Rustyiron
Super Member
You Canadian guy's sound like you have a great resource at this "Princess Auto":thumbsup:
oldnslo
Super Member
1/2 hose at 15 GPM is approximately 5 PSI per foot pressure drop. This does not include any fittings.
Ya we have one good resource....... but you guys have hundreds, lol.
I talked to the hydraulics guy at Princess Auto about this. I'm concerned the hose is too small. I finally got to give it a good run today. I made another, better temporary mount. I was anxious to give it a real try with the new snow. I think this will work well enough for me. I ran down the entire driveway in some pretty heavy snow. I'm guessing it was blowing the snow about 20' tops. Good enough to work for me,, since I don't have to back up. But there is a concern. About 1/2 way down the driveway I could tell the hydraulic lines were getting hot and I thought I could smell hot oil. I stopped and touched the steel aux hydro lines and they were so hot I could not keep my hands on them. Back up to the shop and check the hydraulic tank level and sure enough it was low. Filled it up and went at it again but the same thing. The lines are getting too hot. I think it is because they are too small and the velocities are very high. Something like 22 fps according to a graph that PA had in a brochure. I could put larger lines between the aux connections but the lines from the SS to the connections are only 1/2". Seems kind of dumb to me.
