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Thread: ESE's works engine tuner

  1. #32296
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    18th May 2007 - 20:23
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    Quote Originally Posted by Frits Overmars View Post
    My approach for such operations: pull a piece of tight-fitting inner tube over the piston and gently (but not too gently; it's not your sister) clamp it in the lathe.
    This won't be sufficiently accurate for a complete ring groove fabrication, but it will do for the limited angle of rotation required to grind away the pin.
    My method is similar, I have had success using masking tape to make up for the taper in the piston. It is also possible by carefull positioning of the chuck jaws to compensate for the piston cam.

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    I have had some success filling away the ring peg with a slim file with the teeth on the flats ground off. Carefully grinding the file to the ring width and slightly radising the edges to protect the sealing surfaces of the ring land worked well.

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    The new peg was made from piano wire with it secured by bending the tip over into a hole like Yamaha did on their TZ's.

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  2. #32297
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    Click image for larger version. 

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    I had problems with Weisco forged pistons. If they got over heated in my air cooled engine the original ring locating pin would move further into its hole and allow the ring to rotate. I needed to find a more reliable way of locating the ring.

    Quote Originally Posted by Brett S View Post
    Another option I've thought about but never done is to drill into the underside of the crown behind where the original pin ends and then push the pin in below ID of ring groove.
    Brett's idea may work well, there seems to be plenty of room at the bottom of the Weisco pin hole to be able to punch the ring locating pin down a lot further.

  3. #32298
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    13th February 2016 - 09:21
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    Don't forget soft jaws. Tight, concentric and scratch-free.
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  4. #32299
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    19th October 2014 - 17:49
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    As an aside, when using tiny drill bits you can bump up the stiffness with a single flute version. I used one of those in carbide to put some oiling holes in case-hardened linear shaft and there was a distinct lack of drama during the operation (much to my relief).

    cheers,
    Michael

  5. #32300
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    27th October 2013 - 08:53
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    for the hell of it, i just might pickup one of these to see how well it removes the pins on some old pistons.. in my mind im thinking it could be the bees knees. chuck it up in the drill press jaws and just plunge down. essentially the same as drilling but the cutter is flat on the end with teeth and solid carbide so deflection would likely be nil. should mill the pin away in no time

    https://www.travers.com/4-flute-micr.../p/08-601-038/

  6. #32301
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    Quote Originally Posted by TZ350 View Post
    Click image for larger version. 

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    I had problems with Weisco forged pistons. If they got over heated in my air cooled engine the original ring locating pin would move further into its hole and allow the ring to rotate. I needed to find a more reliable way of locating the ring.



    Brett's idea may work well, there seems to be plenty of room at the bottom of the Weisco pin hole to be able to punch the ring locating pin down a lot further.
    I suppose officially the hole shouldn't be deep enough to let the pin go down too far if the interferance fit is wrong..
    I have had a customer with the issue before on a batch of IAME kart pistons and i suggested to work out where the end of the pin is(cut open a failed one to see pin length) and centerpop the underside of the crown to both stop the pin being able to go in any further and hopefully increase the interferance fit.
    I never heard back from him to know if it fixed the issue.

  7. #32302
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    22nd November 2013 - 16:32
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    Quote Originally Posted by Brett S View Post
    I suppose officially the hole shouldn't be deep enough to let the pin go down too far if the interferance fit is wrong..
    I have had a customer with the issue before on a batch of IAME kart pistons and i suggested to work out where the end of the pin is(cut open a failed one to see pin length) and centerpop the underside of the crown to both stop the pin being able to go in any further and hopefully increase the interferance fit.
    I never heard back from him to know if it fixed the issue.
    Jeez Brett, just where do you get all these good ideas from ?????
    "Success is the ability to go from one failure to another with no loss of enthusiasm.”

  8. #32303
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    Quote Originally Posted by TZ350 View Post
    The new peg was made from piano wire...
    That is my favorite source. The material is top notch, available in any diameter you need, and one string is enough to modify at least a hundred pistons.

    Quote Originally Posted by TZ350 View Post
    I had problems with Weisco forged pistons.
    Did you misspell that name on purpose? Never mind, now I can divulge that I've never seen anything good coming from them, without having to worry about lawsuits.

  9. #32304
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    18th March 2012 - 08:35
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    Funny thing,, you discuss moving the pin.
    I have the latest days tested moving one my self as i can´t find desired piston needed for my setup.

    I use a different approach, which i suppose is the 'best' way.
    I use Spark erosion to remove old pin.
    Click image for larger version. 

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    This leaves me with totally untouched ringgroove.
    And when pressing in a new pin i used my cnc mill, drilling a hole with a tungsten 1.5mm diam drilling mill.
    And the pin i made from an shaft of a 1.55mm drillbit.
    Small taper on the end that goes in first in the piston, then just press it in.
    I made the pin go all the way down in the hole i drilled, and by that forcing it to NOT move inwards into the piston, and as my ring closes the gap it won´t let the pin move outwards either.

    And, if worried about spark erosion might spark onto the sides of the groove, one can either paint the piston or mask it with some thin tape.

    Rgds
    Patrick

  10. #32305
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    Quote Originally Posted by peewee View Post
    for the hell of it, i just might pickup one of these to see how well it removes the pins on some old pistons.. in my mind im thinking it could be the bees knees. chuck it up in the drill press jaws and just plunge down. essentially the same as drilling but the cutter is flat on the end with teeth and solid carbide so deflection would likely be nil. should mill the pin away in no time

    https://www.travers.com/4-flute-micr.../p/08-601-038/
    I use a similar one, but,, be aware!
    They need about at least 3000rpm and about at top 0.02mm feed per tooth.

  11. #32306
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    13th December 2018 - 18:06
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    I believe I'm right that the top model has more balancing effect per rotational mass than the lower, and thats what we want right?
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  12. #32307
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    8th February 2007 - 20:42
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    The efficacy of a balance shaft is dependant upon two factors = m x r.
    If you take the whole mass as being at a single point then that mass at the radius squared is the rotational inertia.
    In the diagram it would appear that the bottom shaft has more eccentric mass within the same outer radius , thus will
    have more rotational ineria effect.
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

  13. #32308
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    Quote Originally Posted by wobbly View Post
    The efficacy of a balance shaft is dependant upon two factors = m x r.
    If you take the whole mass as being at a single point then that mass at the radius squared is the rotational inertia.
    In the diagram it would appear that the bottom shaft has more eccentric mass within the same outer radius , thus will
    have more rotational ineria effect.
    I'm not shure I followed, say lets design the two to do the same job- then the upper would give faster accelleration?

  14. #32309
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    Sure - less ineria = faster acceleration.
    But either you balance the crank properly or you dont - cant have both.
    A crank with no balance shaft simply moves the shake from the vertical to the horizontal plane as the balance % is increased.
    Balance shafts can eliminate the shake altogether, if thats what you want or need,
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

  15. #32310
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    Quote Originally Posted by wobbly View Post
    Sure - less ineria = faster acceleration.
    But either you balance the crank propderly or you dont - cant have both.
    A crank with no balance shaft simply moves the shake from the vertical to the horizontal plane as the balance % is increased.
    Balance shafts can eliminate the shake altogether, if thats what you want or need,
    I Don't intend to compromise the balancing act in any way, just better designed. Damn my minimalism. It must have larger diameter/length/density, but the more centered excentricity I think could make it possible to lose some inertia.

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