LRO: RE: Engine Balancing

From: Tackley, John (jtackley@dit.state.va.us)
Date: Thu Apr 05 2001 - 15:03:46 EDT

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    > Peter asked...
    "So am going to do a total rebuild. Just wonder if getting the
    thing balanced would be a good idea given the increase in power and to
    improve longevity."

    My response is long, so either get comfortable, or hit 'delete' now.

    Well, let's examine this situation...you will have gone to some considerable
    expense to improve the 2.25, perhaps to keep the truck an original LR or
    just because you like seeing the results (...or lack of same) of your own
    personal engine enhancement theories, whatever. We know from the
    experiences of others that it is possible to increase/improve on the stock
    7:1 comp. 2.25 petrol LR engine's (engines, not motors...motors only convert
    electricity to mech. energy, I was taught)HP and Torque curves and peaks.
    Also, there are many routes to that destination. You can increase such
    things as the compression ratio and the displacement by various means, (skim
    the head, change the pistons, bore the cylinders oversize, stroke the crank)
    etc. Simpler and less expensive methods of increasing HP/Torque can also be
    followed, such as increasing the air flow thru the engine by changing to
    higher flow carbs, cams, manifolds and exhausts.
    There are specific costs associated with each of these operations though,
    both in terms of parts and/or labor/machine shop time and otherwise.
    Horsepower by-the-dollar(or pound-sterling, if you prefer...)I like to call
    it.
    The enjoyment for me is to first determine the objective, then develop both
    a budget and a plan for the improvements/modifications, then estimate the
    relative costs of planned changes and then press on. Sometime you win,
    sometimes you lose, but there are no mistakes ever, only lessons.
    Will balancing a LR 2.25 have its benefits...abso-damn-lutely, and don't let
    anyone tell you differently...the issue is; Is the benefit worthy of the
    effort? Or, is it worth the relative cost? Isn't cost a relative issue to
    each of us? What seems expensive to me may come cheap to you, and so on.
    There WILL be a benefit, however slight it may be. Only you can weigh the
    facts and decide.
    When I, or rather my local machine/speed shop) did my 2.25 engine, we
    discussed each of these and other points, they gave me estimates of the
    costs and expected benefits, and then I picked a peddle, to stop or go; I
    made the call. I performed most of the above mentioned mods, and some
    others, including a port&polish of the head (which was bench flowed before
    and after to verify the increase/improvement in flow rates). This in turn
    was matched to flow rate specs for manifolds/carbs and I decided on APB's SU
    carb/Aluminum manifold combo. Add to that an AB header out of
    necessity...what goes in has to get out.
    I have not fired up this engine yet. In the future I plan to utilize a
    SuperTrapp exhaust, which is tuneable via 'discs' that are added or removed
    to change the flow rate of the exhaust system. Essentially, I used known
    techniques for increasing HP and Torque hot rodders have been using for many
    years and threw them at LR's 'tractor' technology engine because I wnated
    to. I am quite certain every one of the mods carried out will have its
    benefit, however slight, and to me, the relative cost (all tallied I spent
    less than $2500 for parts and labor)was well below the cost of a new Turner
    or other known quality re-built 2.25, and $300 of that total was just for
    re-assembling the complete engine and then standing behind that work. The
    guarantee I recieved from the shop was for 1 year/unlimited mileage, which
    commences the day I fire it up for the first time, which will be several
    months after it left their shop(this in exchange for paying them to assemble
    and test, ...yes test, not by actually starting and running the engine, but
    by 'spinning' it up to 500 rpm for a prolonged period of time and checking
    all the things they check to insure quality work). That all made good sense
    to me and seemed a good value, compared to other choices available to me.
    So, back to Pete's question, or rather my answer to it...will balancing have
    any benefit in terms of
    increased power and longevity...abolutely it will. If it develops more HP
    and Torque as a result of your chosen mods, will you not enjoy more
    smiles-per-mile because of them? Will you not rev the engine higher, or
    cruise at a higher relative rpm just because you can, as a result of those
    mods? I'm sure you will and those mods will allow you to do that with an
    increased margin of safety/longevity.
    However, Pete, only you can determine if the 'cost'of whatever you decide to
    do, be it in labor, parts or whatever cost, is acceptable to you.

    Good Luck,

    JT/ric



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