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365 gt 2+2 cam timing

Discussion in 'Technical Q&A' started by 12659, Mar 29, 2011.

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  1. 12659

    12659 Formula Junior

    Oct 6, 2005
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    mark
    #1 12659, Mar 29, 2011
    Question. The manual and the Roush/Riff tuning tips both show intake opening and exhaust closing at 13 degrees 15'. The flywheel attached to my car shows 22 degree marks for AA and CS respectively. I am inclined to believe the flywheel.

    Any ideas?
     
  2. tazandjan

    tazandjan Three Time F1 World Champ
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    Terry H Phillips
    #2 tazandjan, Mar 29, 2011
    Last edited by a moderator: Sep 7, 2017
    How about the data in the owners manual? Most of the early manuals had very complete engine data because that is all a lot of mechanics had. Checking the valve timing is done at 0.5 mm clearance, not the 0.20 mm and 0.25 mm normal clearances.

    Taz
    Terry Phillips
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  3. 12659

    12659 Formula Junior

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    #3 12659, Mar 29, 2011
    Thanks Terry:

    Yes, the manual is detailed and helpful. Strange thing about it is that the marks on the flywheel indicate a discrepancy. The marks show an opening @ 22 degrees instead of 13-15'.

    Had a similar discrepancy a while back, when I learned that the timing port is on the bottom of the engine. The manual shows it on top.... Therefore I question the manual.
     
  4. tazandjan

    tazandjan Three Time F1 World Champ
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    #4 tazandjan, Mar 29, 2011
    I would not worry about the photo too much. The same photo was used in the 250 GTE, 330 GT 2+2, 330 GTC, and 365 GTC owners manuals, but all the timing data was different. Typical Ferrari practice. You have a good photo, so why waste it? Especially since it just shows the PM mark. The difference likely rests with the valve clearance used. The 0.5 mm clearance for cam timing is designed to get you on a more rapidly changing portion of the cam profile than the standard clearance settings. Same thing for the Daytona, where you double the intake valve clearance to time the cams.

    Are you replacing the chain or what are you doing to worry about cam timing?

    Taz
    Terry Phillips
     
  5. 12659

    12659 Formula Junior

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    #5 12659, Mar 29, 2011
    Just doing a normal valve adjustment, and fluid change. I'll try the specified valve clearance and see what turns up, sorry for the pun.

    I enjoy doing this sort of work, and I always look for the absolute truth, which sometimes is hard to find. Last time it was the timing port. Ferrari forgot to inform those of us in the trenches that the 365 gets timed from the underside port, which makes the top port vestigial, or perhaps ornamental.
     
  6. tazandjan

    tazandjan Three Time F1 World Champ
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    #6 tazandjan, Mar 29, 2011
    Remember also, there are timing marks on the flywheel for full advance on the distributor timing. On my old Daytona, timing was checked at 5000 rpm with the quote timing at full advance/high speed was more critical than that at idle. The timing was set on that 365 at the bottom of the engine, too. In the 365 GTB/4 owners manual, they finally decided they did not need that old photo any further.

    If all you are doing is setting valve clearance, you can see the cam lobes for setting clearance as you advance through the cylinders.

    Taz
    Terry Phillips
     
  7. 12659

    12659 Formula Junior

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    #7 12659, Mar 30, 2011
    I have the clearances set, that's no problem. The flywheel marks that I am looking at are AA 22 and CS 21. On other Colombo engines, AA and CS usually refer to intake opening and exhaust closing respectively. Perhaps I am wrong.

    Anyway, I will try the 0.5mm clearance to see if that has the desired effect.
     
  8. 12659

    12659 Formula Junior

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    #8 12659, Apr 3, 2011
    Hi Terry:

    OK, it worked, I used the 0.50mm technique which put the timing marks on the flywheel within 2 degrees.

    There is a lot of contradictory info. floating around about how to check cam timing. On the other hand it just may be me..

    Thanks for the help.

    Cheers

    Mark
     
  9. tazandjan

    tazandjan Three Time F1 World Champ
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    #9 tazandjan, Apr 3, 2011
    Last edited: Apr 3, 2011
    Mark- Seems like every car is different. Daytona uses 0.10 mm. 308s and, I think, 328s use 0.50 mm, like your car.

    Taz
    Terry Phillips
     
  10. 12659

    12659 Formula Junior

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    #10 12659, Apr 3, 2011
    well, the truth has been revealed, thanks for helping to find the truth.
     
  11. Colin Angell

    Colin Angell Karting

    Jun 17, 2004
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    #11 Colin Angell, Apr 4, 2011
    Truth revealed?

    The manual calls for valve to start to open at 13 degrees 15 minutes with the valve clearance set at 0.5mm, but the flywheel is marked AA at 22 degrees. Which is correct? I don't think we've heard a definitive answer yet.

    Out of interst, if you set a pair of dividers to 33mm and place one leg on TDC the other leg will mark a position on the outside of the flywheel at approximately 13 dgrees 15 minutes, which could be useful if you have the engine in the car and cannot fit a degree wheel.

    Any 365 engine tuners out there?
     
  12. 12659

    12659 Formula Junior

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    #12 12659, Apr 5, 2011
    Indeed, what is the deal with 13 degrees 15'? For one thing it is next to impossible to get a 15 minute reading on a degree wheel. I had a side conversation with a pal that worked at the local Ferrari dealership here in town as a mechanic. He mentioned a similar technique. So, for the record I plotted all of the marks on the flywheel and went back to him with the results.

    There are no marks on the flywheel near 13 degrees 15'. My pal recommended following the AA and CS marks on the flywheel. His reasoning was that the factory assembled the engine on those marks. He also mentioned that in the 60's there was an awful lot of error in the printed material that came from the factory, for what it's worth.
     
  13. Colin Angell

    Colin Angell Karting

    Jun 17, 2004
    117
    #13 Colin Angell, Apr 5, 2011
    Well 15 minutes is one quarter of a degree, so probably not too difficult to get reasonably close if you have a large diameter degree wheel and these days it would be fairly straight forward to have a wheel marked off on a CNC machine at any angle you want, but there is a big difference between the two numbers. Which one is correct?
     
  14. Lee Eastell

    Lee Eastell Rookie

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    #14 Lee Eastell, Nov 22, 2018
    Hi
    I am in the process of replacing my timing chain and wondered in anyone has any idea where I could get hold of a workshop Manual.
    Thanks Lee
     
  15. Motob

    Motob Formula 3
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    #15 Motob, Nov 23, 2018
    What model Ferrari do you have? Almost all of the technical information is located in the owners manual.
     
  16. Lee Eastell

    Lee Eastell Rookie

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    #16 Lee Eastell, Nov 23, 2018
    I have the Daytona 365gtb4 with the 251 engine.
    Lee
     
  17. Motob

    Motob Formula 3
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    #17 Motob, Nov 23, 2018
    Lee, besides the owner's manual, Ferrari did produce a shop manual for the Daytona 365GTB/4, but it was only written in Italian. The late Angelo Wallace reprinted many of the early Ferrari shop manuals translated into English. You will have to find one of these in paper form. It is a pretty good manual, I recommend getting one.
    There is a seller on ebay that has copies of the Angelo Wallace manuals for sale. Here is a link to the Daytona 365GTB/4 manual:
    https://www.ebay.com/itm/FERRARI-365-365GTB-4-365GTS-4-DAYTONA-SERVICE-MANUAL-250-275-330-365-512-246-458/232541967493?hash=item362494d485:g:UlgAAOSwldRZ9fAA

    Why and how are you replacing the timing chain? The original chain was a one-piece design that requires complete disassembly of the engine in order to replace. Otherwise you can use a timing chain that has a master link in it and install it by breaking the original chain, connecting the new chain to the original and wind it in by carefully rotating the engine over.
     
  18. tazandjan

    tazandjan Three Time F1 World Champ
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    #18 tazandjan, Nov 24, 2018
    I have one of Angelo's Daytona translations and Brian is correct, very handy for the Daytona. Used it to build a distributor timer for the 4 sets of points and two distributors. Been meaning to scan it and provide it free to Daytona owners since mine is long gone.
     

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