2.0 Boring / Liner Replacement Experience | FerrariChat

2.0 Boring / Liner Replacement Experience

Discussion in '206/246' started by alfadino, Apr 30, 2016.

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  1. alfadino

    alfadino Rookie

    May 2, 2011
    1
    #1 alfadino, Apr 30, 2016
    Hello Ferrari-Chat Dino Group;

    Wanted to reach out for possible recommendations for machinist experienced with the 2.0 Dino block....

    I have a 2.0 Fiat Dino engine block that I had to bore out. The pistons on offer at the time which I purchased from Superformance were the 86.4mm JE Pistons.
    JE recommended bore size was 4-1/2 thousands over piston diameter.

    Once I got the block and pistons back from the machine shop and proceeded to start gapping the rings I discovered ring gap on the Hastings rings supplied with the pistons from Superformance were showing 30 thousands + where the required target is 14-15 thousands ring gap.

    Upon measuring the bore I find all 6 cylinders averaged 11-12 thousands over the 4.5 thousands recommended by JE.

    Already committed, I ordered from Hastings a new set of rings one size up that would get me a tighter gap to work with and proceeded to set them accordingly. Assembled the motor, installed and ran the car a couple years. Eventually unevenness to the idle slowly crept in and I eventually narrowed the culprit to No. 4 during a leak down test.

    Long story short.....

    If another bore step is needed, is it recommended to replace the liners if they are already at 86.4mm ? Or what is the safe bore size allowed for the 2.0 ?
    (I see Superformance is now offering 87.00mm pistons for the 2.0)

    2) If the liners need to be replaced, would the 2300 liner be worth considering for the 2.0 ?

    3) Can anyone recommend a reputable machine shop that has experience with these 2.0 motors for straight boring service using proper torque plates for boring these motors and that also has past experience in boring the block to accept the larger liners for the 2300cc conversion.

    Thanks in advance for any suggestions and contacts that anyone may have.

    Rick
     
  2. swift53

    swift53 F1 Veteran
    Rossa Subscribed

    Nov 17, 2007
    6,733
    E.S.
    Full Name:
    Alberto
    #2 swift53, May 2, 2016
    Hello Rick, I would post same message in the Technical section.

    Regards, Alberto
     
  3. dino clay

    dino clay Karting

    Oct 31, 2007
    185
    san mateo, cal
    Full Name:
    clay cavanaugh
    #3 dino clay, May 7, 2016
    piston clearance is supplied by the piston manufacturer, you must bore the barrels to the that size. I the pistons are 60.25mm, as put on the side of the box, that is the correct o.d. of the bore. You can add a half of one thousands of an inch to the clearance for safety but I put them right on the number. To hold these kind of clearances you must finish to size and then wait until all is at room temperature to do your final honing. I wait to the next day.

    I think you should stop and talk to your machinist until you proceed further

    clay
     
  4. dino clay

    dino clay Karting

    Oct 31, 2007
    185
    san mateo, cal
    Full Name:
    clay cavanaugh
    #4 dino clay, May 7, 2016
    sorry, I didn't read your entire post, these liners, actually,all liners must be installed above the surface of the block by some 0.003 thousands of an inch or head gasket problems will occur. Since your liners are used, this tolerence is probably not correct either. So,you must surface the block, install liners, and then surface the block with the liners installed to the proper peak up.Torque plates are a must. They are also a must for grinding the valve seats in the cylinder heads. I didn't believe that at first but I saw the results with my own eyes and I have been a machinist for over 60 years. You only get one shot at this job so do it correctly. I am in Germany for the rest of this month and you can call me when I return.

    650 430 4134
    clay
     

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