Titanium Wrist Pin

Discussion in 'General Questions' started by Rockjaw, Sep 21, 2014.

  1. Rockjaw

    Rockjaw Member

    I ordered a titanium wrist pin for my 2 stroke 66cc engine..hopefully will stop some vibration on the Micargi

    Anyone know what else it will need? Do I need to buy bushings? if so which?
     

  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    You gonna need a new top end or maybe a whole new engine when that titanium wrist pin gets serious slop in a 100 miles or so........
     
    Rockjaw likes this.
  3. Rockjaw

    Rockjaw Member

    anyone? ...has this happend to anyones motor?
     
  4. jaguar

    jaguar Well-Known Member

    MBR, can you please explain how you think titanium, which is stronger than steel, will wear out faster than a standard steel wrist pin?
    No one has complained of such a miraculous event.

    If it still vibrates too much then you can buy a Jaguar CDI and if its still too much then take the crank out and drill bigger balance holes in it. Click on my signature link to read about it.
     
  5. darwin

    darwin Well-Known Member

    Don't you need a machine to spin the crank to get it balanced right, kinda like balancing a tire to determine where it's out of balance?..............titanium wrist pin should outlast the motor considering all other metals are softer that surround it.
     
  6. jaguar

    jaguar Well-Known Member

    no spinning other than normal engine use.
    the right size balance hole can be calculated. I think its around 12mm for the 66cc but its been awhile since I read my own info on it.
     
  7. Fabian

    Fabian Well-Known Member

    MBR, i am genuinely uninformed when it comes to the fitment and resulting wear differences between a stock standard wrist pin and a titanium wrist pin.
    Can you please short cut my learning curve by explaining how the two different types of wrist pins wear as well as interact with their mating components?
     
  8. crassius

    crassius Well-Known Member

    saw a thread in which that pin failed (even while using the matching bushing)

    titanium is stronger than steel, but much softer - you need a hardened surface for rollers to run on

    I doubt this is any good for our motors.
     
  9. Fabian

    Fabian Well-Known Member

    I have never has a stock standard wrist pin fail, so have never had any need to look for an alternative option.

    If titanium is softer than hardened steel needle rollers, it would be logical to assume that the titanium wrist pin would be the component that suffers an accelerated rate of wear, compared to a stock standard steel wrist pin, especially if you rev the rings out of the engine.

    .
     
  10. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Really?
    here are 2 miraculous pics of failed titanium wrist pins.
    I have more pics as I know of at least 4 failures like these.

    Titanium may be strong but the titanium wrist pins sold by juice are
    obviously not very hard and wear badly.
    the steel wrist pins are very hard and do not wear out.
     

    Attached Files:

  11. butre

    butre Well-Known Member

    strength isn't a factor determining wear in metal. Hardness is the one you're looking for.

    the titanium wrist pin ended up being the cause of my engine's failure.
     
    MotorBicycleRacing likes this.
  12. Fabian

    Fabian Well-Known Member

    That has been my experience with these engines as well as general automotive engines.
    I put preference on reliability over any marginal vibration reduction, and that's a debatable subject, considering a single cylinder engine cannot be balanced. It is by nature an inherently unbalanced design, unless equipped with balance shafts.

    When Jaguar designs a dual balance shaft system for these engines, then, and only then will i agree with him that the Chinese 2-stroke engine can be balanced by clicking on his """signature link""".
     
    Last edited: Sep 22, 2014
  13. Fabian

    Fabian Well-Known Member

    Additional information on engine balance and vibration.















     
    Last edited by a moderator: Dec 15, 2015
  14. jaguar

    jaguar Well-Known Member

    this place can make a quality wrist pin from titanium but at the high price of $150:
    http://www.paeco.com/Titanium Products.htm
    Best to try the Jaguar CDI and then balance the crank if that doesn't suit you enough.
     
  15. abikerider

    abikerider Member

    I'm not sure where you are getting your info from but titanium is weaker but lighter than steel. It's kinda in between steel and aluminum in weight and strength. I would definitely think it would wear more quickly than steel.
     
  16. Fabian

    Fabian Well-Known Member

    There seems to be conflicting information and physical evidence about the strength of titanium and it's wear properties, considering the site which is listed by Jaguar, saying this: The following new items, made from titanium, were introduced by PAECO in 1999. Titanium is a unique metal that is approximately twice as strong as steel, but only one half the weight.

    If that is the case, then how can something twice as strong as steel, be weaker than steel in wear properties, as evidence shows in MBR's photos.
     
    Rockjaw likes this.
  17. Rockjaw

    Rockjaw Member

    Only one way to find out..ill be the doner ...ill try the wrist pin and if it blows the motor..i have tons of engine kits ;) And I think I may be getting all of this vibration on my chopper because of the stem piece welded mount ..i may cut the stem off and try these mounts shown in this pic.
     

    Attached Files:

    Fabian likes this.
  18. butre

    butre Well-Known Member

    I've already found out, it's not something you should be trying. fix your mounts and your engine will stop vibrating
     
    Rockjaw likes this.
  19. jaguar

    jaguar Well-Known Member

    butre, two questions:
    1) how many miles before the engine started making noises due to wear on the titanium wrist pin?
    2) were you using a high compression head and if so which one and do you know the cranking pressure?

    I have emailed Trick Titanium for a cost on a wrist pin. This is from their web site:
    "Trick Titanium wrist pins with the DLC coating offer up to a 40% weight reduction over stock steel pins. We use Ti 17 exclusively in our wrist pin applications for its proven performance and increased durability over Ti 6-4. We have made an exhaustive effort to find the right blend of material and coating technologies to meet your needs. DLC is a carbon-silicon-diamond like coating that offers outstanding wear characteristics and hardness. It is the real deal!"
    So we can deduce that the type of titanium is important as well as the wear resistant coating.

    This site has a coating to use on wrist pins: www.carbonraptor.com/pdfs/Wrist_Pin.pdf
     
  20. butre

    butre Well-Known Member

    that wrist pin had 400 miles on it before it started making noises. I never tested cranking pressure but compression ratio was 10:1
     
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