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timing chain adjuster

Discussion in '365 GT4 2+2/400/412' started by SouthJersey400i, Feb 19, 2014.

  1. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    27,114
    Austin TX
    Full Name:
    Brian Crall
    It has been years since I did any work on these motors but back in the mid-late 80's I did quite a bit. I reviewed the thread and a parts book to refresh my memory and I have a few points.

    We did, in the old days replace chains routinely with very little disassembly. After a few tries with the cams in I decided it was just easier and less hazardous for the valves to take the cams out. Took time but not really difficult.

    As far as the tensioner goes mid production of the C4 it got a total redesign. The original is pictured in the C4 manual if memory serves. During 400 production PN 118321, the piece the adjusting screw bears against was upgraded from phenolic material to steel because the former were breaking. As you can see, time did not stop. They did make improvements.

    We never saw serious wear to the guides or tensioner rubber. If the chain was overtightened it caused failure of the small cage bearings in the idler sprockets, not the rubber parts. Rubber was the material commonly used by many car manufacturers then. I don't think anyone worried about it lasting 30 years. I suspect age and oil exposure is the culprit there.
    If those are to be repaired or reproduced I would suggest Teflon or some similar material. I would also check with restoration shops specializing in European makes or peruse Hemmings to see if such a repair service already exists.

    And finally some Ferrari lore applicable to that motor.

    The story was that Pappa Agnelli had a nephew in engineering school and that engine variant to the basic 365 motor with the long chain and the intake ports through the center of the head was his final project in school. Well being the old mans nephew it now needed to go into production to keep peace with the Agnelli's. It was decided to use it for a limited production car so it's impact, good or bad could be contained, hence the C4 and it's new motor design.
    At that point it is unclear if the production cost or Agnelli juice caused it to survive while the Daytona design died but I think either is possible.
     
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  3. wrxmike

    wrxmike Moderator
    Moderator Silver Subscribed Owner

    Mar 20, 2004
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    Michael
    Good story, hadn't heard that before.
    The 365/4xx carb engine is a masochists delight, access to the distributor is hopeless, too many sidedraft carbs, no room to remove the air filter elements, pathetic layout of the accessory drives for alternator(s) power steering pumps etc, monster chain that streches, all topped by the need to remove the engine to change the internal water pump bearing. What's not to like? :)
    When you look it like that, it does sound like junior's first engineering project.

    M
     
  4. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    27,114
    Austin TX
    Full Name:
    Brian Crall
    #103 Rifledriver, Apr 15, 2014
    Last edited: Apr 15, 2014
    Great cars with a Chevy motor.

    The modern chain driven motors aren't terribly different as far as serviceability goes. They are just newer so not many have needed to pay for repairs yet. They cant be bothered to put a water drain plug in them so I don't think they care about serviceability. And when Hyvo chains wear out there is usually a long parts list.
     
  5. kaiser

    kaiser Karting

    Dec 17, 2011
    73
    johannesburg
    Just a thought. Is the Colombo V12 an interference engine?
    I ask, because when I got my car, I got it partly because they could not start it. They thought the problem was the one fuel injection bank. Well, the one side was stuck, but more seriously, the cam timing was made at the wrong mark on the flywheel, and was about 75 degrees out on all four.
    While trying to replace the spark plugs, the last one on my tour, the rear right, was stuck absolutely solid. The short and long, and it WAS very long, was that I had to have the remaining sparkplug thread spark eroded. Which necessitated the removal of the one head.
    During this, I discovered that the spark plug had most likely never been replaced! and secondly, that one lonely valve on that side was bend. It was straightened and the head reconditioned.
    I then took compression tests on the engine, and 9 cylinders were up to spec, and three low. Upon pouring oil in the bores, they came up to spec as well, indicating the problem is rings, hopefully just stuck from 12 years of inaction!
    That indicates that the valves in the engine are OK, in spite of the wrong cam timing.
     
  6. Fritz Ficke

    Fritz Ficke Formula 3
    Rossa Subscribed

    Jan 3, 2006
    1,870
    Tucson, AZ.
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    Fritz Ficke
    Thanks for your advice and coming in on this thread. For you to share your hard earned knowledge freely is greatly appreciated, now if I can find lawyers and doctors who will do the same....
    Yes, I was at AMU service pistol from 95 to 98, My time in the active Army.
    I am sure we know many of the same people. I only got a 6 point rifle leg and that is as far as I got to double distinguished.
    Your private mail box is full, Fritz
     
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  8. 180 Out

    180 Out Formula Junior

    Jan 4, 2012
    997
    St. Louis, Missouri
    Full Name:
    Bill Henley
    Question: if my engine is not making any chain noise, should I leave the tensioner adjustment alone? I have a really strong if it ain't broke don't fix it rule.
     
  9. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    27,114
    Austin TX
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    Brian Crall
    I would leave that determination to someone who has a real history with them. Your idea of a normal sounding 400 motor and mine or Pat Ottis's may be very different.

    Besides a 400 goes through chains in much the same way it goes through gas. If you have been driving it, it's been stretching.
     
  10. 180 Out

    180 Out Formula Junior

    Jan 4, 2012
    997
    St. Louis, Missouri
    Full Name:
    Bill Henley
    Mr. Ottis's shop is just around the corner from me. I wonder if I could stop by and ask him to give the car a listen. It's a wondrous place. The other day I was driving by and out of the corner of my eye I spied a Testarossa being loaded onto a small car carrier. They let it warm up a bit, sitting on the broken pavement of 10th Street in Berkeley, then vrroom vrroom up the ramps it went.
     
  11. blkprlz

    blkprlz Formula 3

    Mar 24, 2007
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    Bruce
    +1!!

    :D LOL :D They're out there, you really have to pick through them…it's a lot of work :(
     
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  13. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
    414
    Missouri
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    Greg
    I also appreciate Brian's input. It is especially important for those of us who live well away from anyone who has ever heard a Ferrari running let alone knows how it ought to sound.
    I have a tick-tick-tick sound upon start up that seems to be an alternator bearing. I say that because the stethoscope is loudest on the alternator. This goes away when the engine is fully warmed. I am reluctant to mess with the tensioner as a result.
    From Brian's post about heat I think I am all right but the doubt is still there.
    Greg
     
  14. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    27,114
    Austin TX
    Full Name:
    Brian Crall
    The poly-flex belts are famous for that. Take the belt off and see what happens.
     
  15. alastairhouston

    alastairhouston Formula Junior

    Apr 19, 2009
    575
    Largs Scotland UK
    Full Name:
    Alastair Houston
    Hi Greg
    spray some wd40 or more classy Wurth lubricant directly onto the belt at the alternator and the tick tick will go away like magic.
    Regards
    Alastair
     
  16. Ashman

    Ashman Two Time F1 World Champ
    Silver Subscribed Owner

    Sep 5, 2002
    28,579
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    Like Brian and Alastair said, the ticking noise is the alternator belts. It seems to go away if you are driving the car regularly so I think that the belts take a "set" if the car has been sitting for a while. Mine made that ticking noise for a while right after I bought it and then, with much more regular use than the previous owner gave it, the noise seemed to go away, even after just starting the car. A couple of years later, I replaced the belts when I had the alternators rebuilt and never had a problem with the ticking after that.

    Also, I think that older belts are more likely to do that, maybe because the rubber has hardened a bit. It is not a serious issue no matter what and, as you said, it goes away after the car has been running for a while. The WD40 or other type of treatment may help.
     
  17. Ak Jim

    Ak Jim F1 Veteran
    Rossa Subscribed Owner

    Dec 23, 2007
    5,508
    North Pole AK
    Here's my question. What happens if the chain is too loose? In my car I originally thought that I had the noisy belt issue but then I realized it wasn't getting quieter when the car warmed up. I tightened the adjuster about 2/3 of a turn and the noise is now gone. I'm wondering what if any damage has been done to the engine.
     
  18. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,354
    Romulus, NY (Finger Lakes)
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    Ken Battle
    Somewhere in this thread one or more people said they could fabricate new pieces with better, more modern 'wear' material. Let's use this forum to decided who is the most capable and then I will ship him my old parts (free ship to US).
    Ken
     
  19. GT Jones

    GT Jones Formula Junior
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    Oct 15, 2011
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    Christian J
    ken, can you post up as few pics of the worn parts?
     
  20. blkprlz

    blkprlz Formula 3

    Mar 24, 2007
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    Bruce
    Ken;
    I know that b3tech (boyd bowdish) makes replacement chain tensioner pads, check to see if he can fabricate the adjuster pad too.

    Check b3tech's post #11
    http://www.ferrarichat.com/forum/365-gt4-2-2-400-412/151081-pros-cons-330-365-2-2s-400-412-a.html#post136737268

    PM him or contact him @:
    b3tech@earthlink.net
     
  21. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
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    Ken Battle
    #118 SouthJersey400i, May 17, 2014
    Last edited by a moderator: Sep 7, 2017
  22. blkprlz

    blkprlz Formula 3

    Mar 24, 2007
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    Bruce
    Wow, just noticed this Ken, you were down to nothing :eek:
     
  23. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,354
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Bruce
    If I knew what it was going to take top replace it; I probably would have left it in with a new chain!
    Ken
     
  24. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
    414
    Missouri
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    Greg
    "The primarly purpose of the tensioner is to take up the slack of the chain on the overrun, when the engine is decelerating and the chain is unloaded, because if there's too much slack in the chain, the undamped whip in the chain could lead to it skipping a cam gear tooth on the overrun."

    Mine is very quiet. Where I live I cannot get the engine to the red line in any other gear than low (TH-400). The guy I got the car from is an engine builder of mostly GM V-8s but also assorted Ferrari engines. His take is that it runs too well to have a chain issue. I have no paper records of any adjustments. It is an '84 400i.

    I have left well enough alone. If the chain skipping problem is upon rapid deceleration, am I not OK leaving well enough alone?

    Greg
     
  25. GT Jones

    GT Jones Formula Junior
    Silver Subscribed

    Oct 15, 2011
    667
    Lincoln, MA
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    Christian J
    Ken, Dave at SRI is interested in the project and I'm happy to facilitate. Can you contact Dave at ****************@aol.com to discuss sending the old pieces to his shop? PM if you want to discuss.
    Christian
     

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