TL150 291ft/lbs trque, TL250 240 ft/lbs?

Discussion in 'Heavy Equipment & Pavement' started by trailmaker, Aug 4, 2008.

  1. trailmaker

    trailmaker LawnSite Member
    Posts: 66

    Anyone have any thoughts on why TK would drop torque down so much on the new model? I know they have a new Kubota engine in this model but what aspect of the new Kubota warrants the big drop in torque? :confused:
     
  2. northmiss

    northmiss LawnSite Member
    Posts: 12

    I notice the 250 is tier 3 compliant. Emissions requirements often lead to engine changes in heavy equipment. The difference in engine operating torque is substantial in these two models--198 foot-lbs at 2600 rpm on the newer model, 232 foot-lbs at 2200 on the older one, both figures being gross torque before accessory power loss is substracted. I didn't calculate net torque since that number isn't supplied on the 150 brochure.
     
  3. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Posts: 4,276

    The engine lost 39 cubic engines so what did you expect?
    Torque is 100% percent related too engine size.
    Hp is a derivative of torque and rpm.
    It acheives equal hp but needs more rpm too acheive it.
     
  4. trailmaker

    trailmaker LawnSite Member
    Posts: 66

    AWJ, my question wasn't why does a smaller engine have less torque, it was why would TK go with an engine that has less torque when usually you see new models trying to up all the specs slightly. Thanks Northmiss, it sounds like they made the change to get tier 3 compliance.
     
  5. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Posts: 4,276

    Unfortunatley engineers build skid steers and that was what they felt was the best match.
    Bobcat uses the same engine in there 330 series as well.

    Yanmar supplies all of the engines(Tier III) across the board so not sure why they did not step up on the big engine.
    Maybe it was not ready for production?
    On there website they no longer have that series engine listed.
     
  6. BIGBEN2004

    BIGBEN2004 LawnSite Senior Member
    Posts: 823

    Maybe the Torque rise is higher which sometimes makes up for a lower number. I know the torque rise is a rating that is never displayed in earthmoving equipment but is bragged about in the agriculture market.
     
  7. DUSTYCEDAR

    DUSTYCEDAR LawnSite Fanatic
    from PA
    Posts: 5,137

    i want more power
     
  8. northmiss

    northmiss LawnSite Member
    Posts: 12

    Torque rise appears to be 25% in the old model, about 21% in the new so there would appear to be no advantage here for the new machine. Hard to know how important torque rise is for the machines these days. My dozer will only lug down about 100 - 120 rpm under a heavy load so it really doesn't back very far up the torque curve, and it never ever lugs down to peak torque rpm, so these peak numbers don't seem very meaningful to me. Since there appears to be no difference in these two loaders' fuel consumption, the only thing I can guess at is emissions difference warranting the engine change.
    As far as AWJ's idea that torque is 100% related to engine size, that really isn't true. Many if not most manufacturers of heavy equipment will equip a given machine series with the same displacement engine and simply vary the turbo boost pressure (along with fuel delivery) to increase torque at a given rpm. The Deere 450J - 650J series dozers would be a good example of the idea. All have the same sized engines, but very different torque numbers.
     
  9. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Posts: 4,276

    Well of course not when you are comparing a non turbo too a turbo engine.
    Torque is 100% related too engine size.The larger the engine the more torque.
    Engines will make a certain ft/lbs per cubic inch and there is a maximum that they will make.Thats why we have bigger engines and not just bigger turbos.
    On the other hand Hp is a derivitive of torque and rpm so you can make the same torque but not the same hp or vice versa as in the case of the smaller Kubota engine.
     
  10. Nelson M Martin

    Nelson M Martin LawnSite Member
    from Ontario
    Posts: 190

    Most engines will max out the torque in the 1500rpm range. The higher the rpm the more H.P. but not exactly more torque. But depending on the fuel ratio vs cubic inch the engine will spec better on the torque curve. The difference in torque specs per cubic inch is when one engine has ...example 80 hp @2500 rpm or another engine will have 80 hp @ 2000 rpm ......
     

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