Hydraulics questions

[woodlandfarms]

Two questions... One asked by a friend of mine and my own. My PT is rated at 65 HP, but there has been lots of conversations here that it is really only about 35hp. A friend asked why the Hydrostatic tractors only have a 20% drop. I said it was because of the fact they still have transmissions and grears, that the PT is just pushing oil against motors... How wrong am I?

The second is from me. When the lifts go out on the PT, or more money flows in, I want to take out the FEL hydraulics and beef them up to something more along the lines of the 1445. Outside of the steel on the arms, is it just buying a hydraulic piston that is larger (say 2" instead of 1.5" diameter?) or is it something else I am missing?

 

[J_J]

Two questions... One asked by a friend of mine and my own. My PT is rated at 65 HP, but there has been lots of conversations here that it is really only about HP. A friend asked why the Hydrostatic tractors only have a 20% drop. I said it was because of the fact they still have transmissions and grease, that the PT is just pushing oil against motors... How wrong am I?

The second is from me. When the lifts go out on the PT, or more money flows in, I want to take out the FEEL hydraulics and beef them up to something more along the lines of the 1445. Outside of the steel on the arms, is it just buying a hydraulic piston that is larger (say 2" instead of 1.5" diameter?) or is it something else I am missing?

On the first question, what does he want to know, it is unclear. The total Hp of the engine, has to be spread around to run the tram pump, the steering pump, and the PTO, So in some situations, all the pumps are running at the same time. There should be enough available HP to run the machine. The cu in displacement size of the tram pump will be selected to use some of the HP, and the other pumps will use some of the available HP.
Maybe he is talking about efficiency, I believe that hydraulic motors work at about a 80 % efficiency. If you expend 10 hp to run it, the hydraulic motor, will only put out about 8 hp.

On the cylinder size. of course the larger diameter cylinder will give you more power. You are increasing the cu in displacement, and more surface area to push against. Just go the the tech help section of Surplus Hydraulics web site and put your figures in the required blocks. You will need bore size, pressure, and shaft size. Also keep in mind that the push side will have more capable lift in lbs, because the shaft on the other side of the piston is taking up space. If you look at cylinders ratings, you will see push lbs, and pull lbs. You will also have to match up length and end mounts.

Somehing else to think about, even if you replace the lift cylinders with larger cylinders, and you can lift a larger load, you will still be limited by the weight of the machine in order to keep all four wheels on level ground. What that means is that you will have to add extra weight to the back end, and will your front wheel axles be able to stand up to the extra lifting weight.

 

[J_J]

I reread your post and noticed that you mentioned piston size, The piston size has to match the bore. In order to get more power,you have to go to a larger cylinder which will have a larger piston. More surface area.

 

[woodlandfarms]

We were discussing grunt force, and that, using HP as a scale, the PT is lackluster for 65HP.

As for the upgrade on the FEL. I mean the whole thing, piston, sleeve, cylinder... for the life of me I cannot remember today what the name of all of this is..

As for weight, seeing as the my PT is 2 tons, and I cannot lift the rear when the front is weighted down, I have room for improvement.

From what Terry told me, the 1845's and 1850's had the FEL capacity deliberately reduced so that they can keep the 45 degree pitch. From what I understood, you can put 1200lbs and the end of the 1850FEL, raise it to 6 feet, and go tromping across a 45 degree slope with no threat of going over. Above 1200 lbs the bet is off.

For me, 2000lbs of lift would be more than enough. My issue is that with the grapple and bucket, I only have 700 lbs or so of lift capacity. Quite a bit for most stuff, but grab hold of a large log and just sit and spin. My buddies 25hp case lifted the log in question - no problem...

Carl

 

[cqaigy2]

As for the upgrade on the FEL. I mean the whole thing, piston, sleeve, cylinder... for the life of me I cannot remember today what the name of all of this is..
Carl

Hydraulic Ram?

 

[RegL]

We were discussing grunt force, and that, using HP as a scale, the PT is lackluster for 65HP.

As for the upgrade on the FEL. I mean the whole thing, piston, sleeve, cylinder... for the life of me I cannot remember today what the name of all of this is..

As for weight, seeing as the my PT is 2 tons, and I cannot lift the rear when the front is weighted down, I have room for improvement.

From what Terry told me, the 1845's and 1850's had the FEL capacity deliberately reduced so that they can keep the 45 degree pitch. From what I understood, you can put 1200lbs and the end of the 1850FEL, raise it to 6 feet, and go tromping across a 45 degree slope with no threat of going over. Above 1200 lbs the bet is off.

For me, 2000lbs of lift would be more than enough. My issue is that with the grapple and bucket, I only have 700 lbs or so of lift capacity. Quite a bit for most stuff, but grab hold of a large log and just sit and spin. My buddies 25hp case lifted the log in question - no problem...

Carl

Now it makes sense. I wondered why the 18xx tractors only had the same lift capacity as the 1430. If your loader is like mine it's probably kind of fast so I would think a bigger ram would slow that down some. Still leaves the question, is the loader arms, pivot points, etc. strong enough to take more weight.

 

[MossRoad]

You cannot compare the HP ratings of a PT to the HP ratings of a conventional tractor. They do not work the same at all.

A conventional tractor, even with an HST tranny, is not the same drive system as a Power Trac. A conventional HST has a hydraulic pump that pushes fluid that turns a hydraulic motor that turns a shaft connected to the range selector. Then the rear of the range selector turns a shaft that turns a differential. Those are all gears being turned by the hydraulic motor.

A Power Trac has a hydraulic pump that pushes fluid to four hydraulic motors. There are no gears in the system at all, anywhere.

The two types of machines and HP ratings are not comparable at all, in my opinion. You just have to get the machine that will do the jobs that you need to do.

I, for instance, like to get the chassis size narrowed down, then purchase the largest engine I can get in that chassis.

 

[ponytug]

Wow! If this were right, it would explain alot about the Power Trac specifications. If my math is correct, a 54" wide tractor that has a 30 degree slope limit, would have a center of gravity (COG) that is about 45" off of the ground. (Assuming rigid tires, etc.) i.e. contan(45/27)=30 degrees

On a 1445, that would put the COG about 14" above the wheels, which is clearly not the case with the FEL in the down position. In the up position with a full load, you'd have 1800lbs 7+ feet in the air, and a 3900lb chasis low to the ground. I could see how the combination might have a COG close to 45".

Talk about pucker factor! Not something that you'll see me trying.

Anyone who wants to admit having done something like this? Charlie Illiff had a second hand story of someone with the post driver on a 1430 that managed to tip it. A moving 500lbs, 8+' in the air on a 2500lb chasis...

We're looking for real world experience here!

All the best,

Peter

From what Terry told me, the 1845's and 1850's had the FEL capacity deliberately reduced so that they can keep the 45 degree pitch. From what I understood, you can put 1200lbs and the end of the 1850FEL, raise it to 6 feet, and go tromping across a 45 degree slope with no threat of going over. Above 1200 lbs the bet is off.

For me, 2000lbs of lift would be more than enough. My issue is that with the grapple and bucket, I only have 700 lbs or so of lift capacity. Quite a bit for most stuff, but grab hold of a large log and just sit and spin. My buddies 25hp case lifted the log in question - no problem...

Carl

 

[J_J]

HP is HP no matter how it is generated. Whether that HP gets to the wheels, is another question. You should know that some of it is lost due to hydraulic efficiency, and as I said in an earlier post, only a portion of that HP is applied to the wheel motors. So out of that 65 HP, the wheels may only get 35 HP. Does that mean that another machine is better. Not necessarily.
It all depends on how the machine is used.

 

[Charlie_Iliff]

From what Terry told me, the 1845's and 1850's had the FEL capacity deliberately reduced so that they can keep the 45 degree pitch. From what I understood, you can put 1200lbs and the end of the 1850FEL, raise it to 6 feet, and go tromping across a 45 degree slope with no threat of going over.

Carl

I've never gotten a bum steer from Terry, so I suspect there's a communication problem somewhere. If you ever want to test that thesis, make sure there aren't any innocents downhill of you.