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  1. #81

    Join Date
    Nov 2018
    North Carolina on Jordan Lake
    Quote Originally Posted by TimeBandit View Post
    Do a bit more deeper searching on this forum ... as I remember reading other past threads where folks said they had no issues updating everything but the crank.

    Side-note: Might also consider swapping the automatic for an aftermarket MCCT. Not saying it's the core issue, but OEM tensioner can be quite aggressive IMHO, as it does not let-up whatsoever due to the ratcheting mechanism - aka results in a very very constant tight chain.
    With a manual setup, one can set and maintain the prescribed tension slack min/max.
    Could running too heavy of a weight of oil which results in and higher oil pressure causing the automatic tensioner to ratchet too tight? This could be the cause of broken or overly stretched timing chains? Could also the dilution of water in the oil, the chain`s lack of oil and overheating of the chain with the overaggressive OEM tensioner be a cause?
    Last edited by cjk6119; 12-04-2019 at 11:14 AM.

  2. #82
    TimeBandit's Avatar
    Join Date
    Jun 2016
    Tampa Bay
    How much more psi given what weight oil? Would that really amount to THAT much more tension?? IDK. POA group 4 synthetics are the most weight-stable over temp changes - aka get way less watery at engine temp - thus would be more likely to affect tension - yet not correlation has been drawn. And I heard the opposite theory too - momentary-loss of oil pressure might temporarily slacken/jump the chain, yet the ratchet-mechanism (one-way characteristic) does not allow the tension piston to back-off, aka introduce slack - not even for one split millisecond.

    Rather, the one coorelation has been the vortex. I heard some theories on the cam lobes on the vortex engines and induced chain vibrations.... could the ACCT incrementally take up vibrational-slack until too-tight. Maybe. And/or the typical heating expansion and cooling contraction could also ratchet things up on the very tight side. Who-knows....

    Again, I'm not saying the ACCT breaks chains - else that be the case for all of us - rather that engines that have broke seem to have a tendency to break again, and perhaps switching away from a extremely tight setup could foster less overall stress on these apparently weak chains.
    Last edited by TimeBandit; 12-04-2019 at 03:09 PM. Reason: a misread

  3. #83
    Quote Originally Posted by yellow jacket View Post
    theres a turbo e85 fzr sitting in my buddies shop it use to b a 100+ mph ski at one time. it dropped a valve and messed things up. when he tore it apart the original builder only put the 16 style cam chain in and nothing else. it had the old style vxr cams. it gets new head, valves, pistons and newer style vxr cams with the 16 cam gears + new chain, and guides. with the old style crank.
    here's the turbo fzr which had only the 16 cam chain and guides. it broke off a valve,the chain was still in tack but the guides looked a little messed up. can't say how many hrs it had on the chain...cp pistons,faro valves,new style vxr cams with 16 cam gear,guides and chain.
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    Last edited by yellow jacket; 12-10-2019 at 06:25 PM.

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