interference versus noninterference engine??

Discussion in 'Prime Main Forum (2017-Current)' started by bear15, Jun 3, 2017.

  1. Trollbait

    Trollbait It's a D&D thing

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    Timing chains are more robust than a bike chain. I would not worry about the engine being interference or non with a timing chain.
    I avoid timing belts, but more to avoid the changing requirement.
     
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  2. Redpoint5

    Redpoint5 Senior Member

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    41 posts and nobody ended up answering the OPs question?

    The reply need be no longer than 2 words; either interference or non-interference.

    Guess I'll have to search somewhere else to get the answer.
     
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  3. TMR-JWAP

    TMR-JWAP Senior Member

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    I'm going to have to change my original opinion....if you follow this procedure for installing a cam into the 2ZR-FXE (hybrid) engine, it has you put the #1 piston at TDC and then rotate the cam to line up marks in preparation for installing the chain. I can't see Toyo telling someone to rotate the cam if it were going to hit the piston.


    https://f01.justanswer.com/tracker40/51b686e8-3e65-421c-8344-1a6650c8533b_125.pdf
     
    #43 TMR-JWAP, May 16, 2019
    Last edited: May 16, 2019
  4. PT Guy

    PT Guy Active Member

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    Exactly. There are more important things to be concerned about. Follow the engine maker's recommendations for oil & filter changes and rest easy.

    About asking a service manager...don't get your hopes up. As I noted above, my old Tundra had an interference engine with a timing belt. The service writer and service manager both told me I was wrong. I had purchased the shop manual, and I had to quote them the section and page number to convince them (or at least quiet them). Toyota has...how many dozens of engine models and variants?...and nobody can know all the details about each. If the owner's manual doesn't list a requirement to change the timing belt (and ours doesn't), forget that section of the engine.
     
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  5. m8547

    m8547 Member

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    I have a 4runner with a similar 4.7L 2UZ-FE V8. The engine is interference, but there's been extensive discussion on the forums about it. Apparently the interference is marginal, so if the belt breaks in many cases it won't damage anything. But out of caution it should still be treated as interference. Of course there are many variations of even just that one engine, with different amounts of power and different VVT configuration, and probably other revisions over the years that we don't know about.

    Even with the timing belt, some people have gone double the service interval without a problem. And I can't think of many reports of the belt breaking. The maintenance schedule is extremely conservative (as it should be).
     
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