348 Cylinder Head Torque | FerrariChat

348 Cylinder Head Torque

Discussion in '348/355' started by 348steve, Dec 24, 2018.

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  1. 348steve

    348steve Karting

    Jul 18, 2018
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    Stephen G
    The torquing instructions in the Ferrari shop manual makes reference to the use of a 90 degree angled adopter to be used during torquing down the heads. Torque it to 60nm then turn each an additional 90 degrees. The only problem being that you can't do that with the adopter, so they tell you how to do it incrementally using a special angle measurement tool? Why would someone use this adopter, there appears no reason for it?

    They also go on to talk alternatively about the simple use of an "S.P.S. type wrench" using 70nm? Ya, that seams obviously more appropriate!

    Any ideas?

    What do you use for torque targets on the head studs?
     
  2. Dave rocks

    Dave rocks F1 World Champ
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    Torque + angle has been a fastening strategy for quite some time. It's also my understanding in these situations it's not geometricly possible to swing the full angle in one sweep.
     
  3. 348steve

    348steve Karting

    Jul 18, 2018
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    I get the point about the strategy, I just don't get the point of an adopter that keeps you from being able to run the 90 degrees in one throw. You need to see the tool to understand my question. Photo attached.

    Why would they propose the use of such an adopter?
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  4. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Because they are Ferrari. Just to cause more controversy has anyone measured the length of the adapter and it's effect on the initial 60nm of torque? :)
     
  5. spider348

    spider348 Formula 3

    Nov 3, 2003
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    I don't recall if the head nut locations on my former 348 but on my former 355 the head nuts could not be accessed without the 2 part tool. I purchased the Hill wrench. Excellent quality!
    Also used an Angle Torque Wrench for 90 degree requirement.
    As a point of reference, I scribed each head nut at 90 degree intervals. Marked the head to confirm 90 degree turn. A bit overly cautious!
     
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  6. yelcab

    yelcab F1 World Champ
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    Overly cautious but excellently done. If you read the workshop manual carefully, the specs of 90degrees is actually quite loose.
     
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  8. yelcab

    yelcab F1 World Champ
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    The 348 head tool is a carry over from the QV and 328 heads and that is how it is. Going to the 5V heads, the nuts are moved to the outside of the heads but access is equally restricted and there is no way to swing 90 degree in one go either.
     
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  9. yelcab

    yelcab F1 World Champ
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  10. Dave rocks

    Dave rocks F1 World Champ
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    This tool is on our development list as we plan to make one strong enough to remove the nuts and I happen to have a very good material selection in mind :) As Mitch states, the clearance on a 355 is very minimal and I'd be surprised if you can swing 25 degrees in one pass.
     
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  11. Rifledriver

    Rifledriver Three Time F1 World Champ

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    The adapter is required to be able to use a torque wrench on the nut. No other way known. The design of the head is what limits how far it can be turned each time, not the tool. The head design with cam, valve and port placement were the primary goals, not your convenience. If you can find some way in violation of basic physics to accurately tighten the fasteners with a higher degree of convenience by all means let us know, I for one am all ears.
     
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  12. Rifledriver

    Rifledriver Three Time F1 World Champ

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    Who cares? 60mm was was the spec with tool in use turned to a 90 degree angle. What it is at the fastener axis is of no concern to us.
     
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  13. yelcab

    yelcab F1 World Champ
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    I'll be happy to test it, but I don't know if you need the removal tool. The force it takes to remove the nut is very high and having to apply that over a longish C shaped extension gives way to busted knuckles. A cut off 15mm box end wrench works well enough.
     
  14. Dave rocks

    Dave rocks F1 World Champ
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    I should have clarified - I'm talking 355 which is the 2-piece tool. I'd design the tool to adapt to a longer breaker bar type piece as well. My ground down Snap-On works but I'd prefer something with more clearance.
     
  15. Rifledriver

    Rifledriver Three Time F1 World Champ

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    The factory did make one. They made one batch, enough for all dealers world wide at the time. All subsequent tools were made by another contractor and despite being very expensive, they are worthless. We told Ferrari many times they were completely incapable of doing the job but they really didnt care.

    I have a factory adapter to torque BB/TR case halves, a later production factory tool. The original was forged and broached. This one broke at partial torque first time I used it. Its cast and electroless nickel plated so you cant tell. . No conceivable way it can perform the job it was made to do. Very typical of Ferrari. People who are assigned to reproduce parts and tools have no idea of the job needing to be performed, just told "Make some that look like this".
     
  16. johnk...

    johnk... F1 World Champ
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    #16 johnk..., Dec 24, 2018
    Last edited: Dec 24, 2018
    With the extension/tool at 90 degrees relative the torque wrench the torqued applied to the nut is what is read on the torque wrench.

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  17. yelcab

    yelcab F1 World Champ
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    I am talking about the 355 tool. To remove the nut, I have a 15mm wrench ground to bit, cut off one end and slip a 7 inch tight fit cheater bar and it works … well enough. I can replace it for 10 bucks.
     
  18. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Hey Merry Xmas! Good to see you posting.

    It matters to DIY guys without the factory tool. I'm with Mitchel and I will make a tool in my garage right now to do the job. It is not that complex and much faster to heat, bend, weld, and heat treat a tool. I do it all the time...I don't have multiple cars to repair at the same time and thus keep working so waiting for the Snap-on truck or a delivery from Hill is a no brainer.
     
  19. SoCal1

    SoCal1 F1 Veteran
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    My new years evolution is to use the blue wrench more
     
  20. 348steve

    348steve Karting

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    Have we determined that you don't need one for the 348? I'll find out soon enough as the heads will come off shortly. Just curious to see.
     
  21. m.stojanovic

    m.stojanovic F1 Rookie
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    #21 m.stojanovic, Dec 25, 2018
    Last edited: Dec 25, 2018
    You need the "duck foot" tool (or something similar). The head nuts are under the top part of the head casting:

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  22. tbakowsky

    tbakowsky F1 World Champ
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    Made my own "L" tools for these. Torqueing down correctly is not an issue if you have a digital torque wrench with angle settings. Mac tools sells just the ticket..pricey but for a guy like me..worth every penny.
     
  23. johnk...

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  24. m.stojanovic

    m.stojanovic F1 Rookie
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    That is correct. As I initially did not quite understand your drawing, I have added some wording (I hope you don't mind). That is why it is necessary to position the torque wrench at 90 deg. to the foot of the "duck" when the length "1" will be zero and will not affect the torque reading/setting.

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  25. johnk...

    johnk... F1 World Champ
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    No problem. If it makes it clear to other it's ok with me. Just one more thing, when positioned at 90*, the angle phi will be zero and sin(0) = 0, and yes, l =0. It also applies to any extension used with the torque wrench. :)
     

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