Water/oil pump chain tensioner | FerrariChat

Water/oil pump chain tensioner

Discussion in '365 GT4 2+2/400/412' started by Al Campbell, Dec 22, 2020.

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  1. Al Campbell

    Al Campbell Formula Junior
    Owner Silver Subscribed

    Nov 22, 2013
    571
    Australia
    Yet another variance I have come across in the 400i engines. :(

    While disassembling the engine I'm rebuilding I managed to break the chain tensioner which was a plastic unit which had become very brittle over the last 40 years.

    It looks like the older engines had the plastic version which was mounted with a bolt and has a dimple that fits into the block to stop it turning.
    The newer one is metal, mounts on a stud and and is tensioned against the timing chain cover.
    It looks like both versions have the same replacement part number so I'm assuming I will need to upgrade to the newer version.

    Has anyone done this before?
    It looks like I will need to install a stud to mount it and machine the timing cover case.
    Is there anything else I'm missing?

    Cheers,
    Al

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  2. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    Hello phenolic chain tensioner was mentioned earlier by @Rifledriver. Replacing these with the newer style seems to be the usual procedure.

    If memory serves me well, the new tensioner is an of the shelf product from Ford, GM, or any of their likes.
     
    Al Campbell likes this.
  3. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall

    You are misquoting me. I spoke of a single internal part of the cam drive chain tensioner adjusting mechanism. .
     
  4. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    Your correct and sorry for the mix-up . On one thread you talked about this phenolic part, by no means you said the metal alternative was an "off-the-shelf" product. This is not what I had in mind, but what I wrote was confusing (obviously).
     
  5. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    Il Tifoso likes this.
  6. Al Campbell

    Al Campbell Formula Junior
    Owner Silver Subscribed

    Nov 22, 2013
    571
    Australia
    Just a word of warning to anyone updating to the later style water/oil pump chain tensioner. The old plastic unit was mounted with a 8mm bolt and the later metal type are mounted on a 6mm stud. As 6mm studs don't screw into 8mm threaded holes I had to machine up a stud out of an 8mm bolt that has 8mm thread on one end and a 6mm stud on the other. You will also need the stepped washer in the top of the picture that goes on the stud before the tensioner.

    Cheers Al
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