News

Torqueing for 308QV/328 Heads

Discussion in 'Technical Q&A' started by tf308, Jan 11, 2004.

  1. tf308

    tf308 Formula 3
    Silver Subscribed

    Dec 14, 2003
    1,091
    Virginia Beach
    Full Name:
    Tim
    I was looking through the service manual and it looks like the proceedure for torqueing the heads is different for the 2 models. Is one better than the other? The 308 used a special wrench L wrench (I used it to get the head bolts off) and is simply torqued to a certain spec; however, the 328 looks like it had an entirely different setup ( a special wrench that is turned another quarter turn??) Do any of you have experience with this?

    I noticed that my new elring gaskets have a reference for a 328. These are probably better updated gaskets, but I just wanted to clarify the proceedure before I continue on.

    Did any of you use the Gasket Cinch that James Patterson references in the Forza rebuild article? If so, did you just put a little around the water jackets?

    ps...The reason my heads were so difficult to get off, was that the coolant from the water jackets had seeped into 2 of the head studs. Over time the mineral deposits simply seized the head to the studs at this junction point. I sure hope these elring gaskets do a better job.


    Thanks.
     
  2. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    The reason there are two different methods for torquing the 308 / 328 cylinder heads is as follows :-

    308 heads have 11x1 mm studs and when assembling the heads onto the block the washer that sits under the head nut is assembled dry and is tightened to 10 kgm

    328 heads have 10x1 mm studs and when assembling the heads onto the block the waser that sits under the head nut is assembled with grease and is tightened using the "L wrench" as described in the manual to 10 kgm.

    It is not recommended by Ferrari or Elring to use any sealer on the face of the gasket, however it is done, but this is a personal thing down to the person doing the job. The gaskets are different from original as they donot contain any asbestos.

    My recommendations are use the tool AV498 not the "L wrench" on your engine, then after 24 hours retorque the heads again.


    MW
     
  3. yelcab

    yelcab F1 Veteran
    Consultant

    Nov 29, 2001
    9,072
    San Carlos, CA
    Full Name:
    Mitchell Le
    I have used K&W Copper Spray with great success. Just my personal experience, not suggesting you do one thing or another.
     
  4. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,562
    USA
    Full Name:
    Hugh G. Rection
    MW,
    I know the 308 series was supposed to have the head bolts retorqued periodically (or at least checked). On the 328 series, I saw a service bulletin, that mentioned a new process for torquing the heads (during manufacturing), which would (supposedly) preclude retorqing. They did suggest "checking" and reporting back if retorquing is necessary.

    What is the determination now? Are 3.2 engines in need of periodic retorquing? I know my independant Ferrari tech does it (at least at the 30k major or any car he has not seen before).
     
  5. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    If you follow the service schedule (Euro cars - not sure for US) the cylinder head torque should be checked at the 12,500 mile service and every 12,500 miles after that, basically every time the valve clearances are checked you should check the head torque.

    MW
     
  6. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    David

    What does it recommend in your service manual for US cars ?

    MW
     
  7. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,562
    USA
    Full Name:
    Hugh G. Rection
    MW,
    I don't know, as I don't have one, and I am not positive of the intervals my Ferrari tech recommends: at each major, or at each valve adjust. Upon reflection, it may be that he said he checks/retorques at each valve adjustment. I know on my 328, he said a couple bolts took almost 1 quarter turn to get to spec., at the last service major service. And it had been serviced only 5 or 6k miles previously (2.5 years) at a Ferrari dealer.
     
  8. Mark 328

    Mark 328 Formula Junior

    Nov 6, 2003
    510
    Orange, Ca
    Full Name:
    Mark Foley
    How do you retorque 328 heads?
    Don't they require you to torque to a figure then go another 1/4 turn?

    When you retorque, do you loosen and retorque and add the 1/4 turn or do you just retorque with a torque wrench to the figure in the manual?
     
  9. yelcab

    yelcab F1 Veteran
    Consultant

    Nov 29, 2001
    9,072
    San Carlos, CA
    Full Name:
    Mitchell Le
    The only way for the technician to be able to make that statement is for him to set the torque wrench at the specified value, put it on the nut and tighten it (without first loosening it) until the wrench clicks.

    So, my guess is he did not first loosen it. Which is probably not the biggest sin there is. It was also what I did when I checked my head nuts.
     
  10. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,562
    USA
    Full Name:
    Hugh G. Rection
    Actually, this is how you are supposed to check them. Set torque wrench to 52lbs, then if any move, loosen and retorque in the proper sequence...according to service bulletin 10-14, dated 9/86. Of course, I didn't ask my technician if he was doing it per procedure, or just as you surmise. :)
     
  11. ants2au

    ants2au Formula Junior

    Nov 19, 2003
    690
    Sydney Australia
    Full Name:
    Anthony

    Didn't someone say the orginal specs for 308 is dry torqueing. But you retorque, the washers are no longer dry. The engine has been run, and there is oil everywhere. Do you think this will affect the torqueing procedure? especially if you have to lossen a bit before retorqueing?

    Just a thought. I know the washer has 52 odd lbs on it, so maybe there will be no chance of oil going underneath it, but when you retorque, the turning motion will invariably draw oil under it.
     
  12. ants2au

    ants2au Formula Junior

    Nov 19, 2003
    690
    Sydney Australia
    Full Name:
    Anthony

    On dry bolts like the Fiat heads, the bolts as accessed from outside the heads. In this case, I always loosen by a 1/4 of a turn before retorquing to spec. They tend to stick with heat cycling.

    As for bolts/nuts in the oilways, see my other post.
     
  13. tf308

    tf308 Formula 3
    Silver Subscribed

    Dec 14, 2003
    1,091
    Virginia Beach
    Full Name:
    Tim
    In the Forza 308 article, James Patterson torques the heads with 30 weight oil. Do you think it really matters whether they are oiled or dry?
     
  14. jbcottrell

    jbcottrell Rookie

    Apr 8, 2004
    31
    Does anybody have the proper torque sequence for a 308? IE: Which bolts are torqued first?
     
  15. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    #15 Ferrari_tech, May 26, 2005
    Last edited by a moderator: Sep 7, 2017
    Here you go..........................
    Image Unavailable, Please Login
     
  16. Lawrence Coppari

    Lawrence Coppari Formula 3

    Apr 29, 2002
    1,840
    Kingsport, TN
    Full Name:
    Lawrence A. Coppari
    I assume the torque sequence is the same for a 328?
     
  17. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    Exactly the same.
     

Share This Page