Page 1 of 4 1234 LastLast
Results 1 to 10 of 33
  1. #1
    Bronze Member
    Join Date
    Oct 2004
    Posts
    50

    Default PT425 vs. PT1430 Mystery?

    There's lots of threads about comparing these two machines, but one thing that's always perplexed me is how the 1430 is able to generate 50% more PTO hydraulic flow than the 425 (12GPM@2500psi vs. 8GPM@2500), when it only has 5 more rated horsepower...

    Obviously one is a diesel and develops its power at a lower RPM, and the torque curves are different, but threads on this forum suggest the traditional pros and cons of gas vs. diesel fall down when you are talking simply about true developed horsepower being applied to a hydraulic pump at the engine shaft.

    So, where does the 1430 get its extra gusto from?

    OnTheWeb

  2. #2
    Epic Contributor MossRoad's Avatar
    Join Date
    Aug 2001
    Posts
    23,001
    Location
    South Bend, Indiana (near)
    Tractor
    Power Trac PT425 2001 Model Year

    Default Re: PT425 vs. PT1430 Mystery?

    I think the larger engine and higher torque allow it to push a larger pump at more GPM.

    Think of a gas engine pickup VS a diesel engine pickup. Even though they are near the same HP and displacement, the torque differences are huge. The torque is what can do the work.

  3. #3
    Super Star Member J_J's Avatar
    Join Date
    Sep 2003
    Posts
    16,711
    Location
    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: PT425 vs. PT1430 Mystery?

    Maybe the lift cylinders are larger, and therefore have more push and pull.

    GPM only changes the cyl speed.
    If both machines have the same pressure, The larger cyl will win ever time.

  4. #4
    Silver Member
    Join Date
    Nov 2004
    Posts
    171
    Location
    Thayer, MO

    Default Re: PT425 vs. PT1430 Mystery?

    Do the PT tractors have a single hydraulic pump that supplies everything or separate pumps for steering, drive, and implements?

    I have been looking for non-PT implements that could be useful with a PT425 but the choices are limited by the low GPM of the hydraulic PTO system. I would be willing to drive slower on stay on flat ground to get some of the larger attachments to work. Afterall, how fast or how steep does one need to drive/climb while power raking/rock picking.

  5. #5
    Platinum Member
    Join Date
    Nov 2002
    Posts
    781
    Location
    Eastern PA
    Tractor
    PT 1845, Bobcat A300, JD Trail Gator

    Default Re: PT425 vs. PT1430 Mystery?

    PT tractors have 3 hydraulic pumps:

    1. a variable volume pump for the drive motors;
    2. a PTO pump that drives attachments (8 GPM for the PT 425); and
    3. a pump for the lift, steering and quick attach systems.

  6. #6
    Banned RonL's Avatar
    Join Date
    Dec 2001
    Posts
    430
    Location
    Worcester, Massachusetts
    Tractor
    Caterpillar 416C IT, Caterpillar D3G, previously owned a Ford 1910

    Default Re: PT425 vs. PT1430 Mystery?

    The difference in hydraulic HP is less than 6 HP.

    RonL

  7. #7
    Super Star Member J_J's Avatar
    Join Date
    Sep 2003
    Posts
    16,711
    Location
    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: PT425 vs. PT1430 Mystery?

    Does this help?

    For a 425 to pump 8 gpm, at 2500 psi, it will require 11.6 hp

    For a 1430 to pump 12 gpm, at 2500 psi, it will require 17.5 hp

    HP=PSI X GPM / 1714

  8. #8
    Epic Contributor MossRoad's Avatar
    Join Date
    Aug 2001
    Posts
    23,001
    Location
    South Bend, Indiana (near)
    Tractor
    Power Trac PT425 2001 Model Year

    Default Re: PT425 vs. PT1430 Mystery?

    Yes, agree about cylinder size. 2500PSI is 2500PSI no matter how you slice it.

    However, the PTO goes by GPM. At 8GPM and 2500PSI you can only turn so much hydraulic motor befor the engine will bog down. If you put a larger pump on the 25HP gas engine, it won't be able to put any pressure behind that flow. So there comes a point when you have to increase the size of the engine if you want to run a pump that has enough GPM @ 2500PSI to turn the bigger motors in the bigger implements.

  9. #9
    Super Star Member J_J's Avatar
    Join Date
    Sep 2003
    Posts
    16,711
    Location
    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: PT425 vs. PT1430 Mystery?

    What you say is true, but let me take this a little further.

    The 25 hp engine is capable of running a 15 gpm pump if that were the only pump in the system. Since the 425 has three pumps, they had to compromise as to speed of turning, lifting, and turning the wheels, and PTO. The HP has to be divided.

    I am sure you have noticed that when going uphill with the implement running full bore, you will start to bog down. You are simply running out of HP. If you cut the implement off, you will gain some HP and may continue up the hill.

    My 1445 has a 13 gpm pump and two other pumps. I can run larger implement, and the wheel motors are larger to push the heavier machine around.

    In theory, the 425 could run the 15 gpm pump, if that is all it did.

    The fact is, if more HP is available, a larger pump can be utilized.

  10. #10
    Epic Contributor MossRoad's Avatar
    Join Date
    Aug 2001
    Posts
    23,001
    Location
    South Bend, Indiana (near)
    Tractor
    Power Trac PT425 2001 Model Year

    Default Re: PT425 vs. PT1430 Mystery?

    The 30HP diesel has about 20% more HP than the 25HP gas engine, but about 50% more torque.

    Our Kohler 25HP is rated around 39 ft. pounds of torque.
    I think the 30HP Deutz is rated around 60 ft. pounds of torque.

    If we hopped up the Kohler to get 30HP out of it, the 30HP Deutz would still pull it all over the place if they were hooked to the same driveline....I think [img]/forums/images/graemlins/crazy.gif[/img], because it has much more torque.

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.