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Countach engine and engine bay refresh

Discussion in 'Lamborghini Supercars' started by sp1der, Nov 20, 2019.

  1. If you recall how much was the wear on the liners? We found mine to be minimal wear, a few are slightly out of round, and we found they have inverse taper? They are wider at the bottom rather than at the top.

    Did you end up re-boring to the next size up or considered that option?

    Finally, is there a link to a Dino manual online somewhere? I've been spending the last two weeks translating the first half of the Lambo L406 manual to English :)
     
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  3. I had a couple of scored liners, and the rest would have needed an oversize re-bore which sourcing pistons for became a touch tricky, so it was easier to get new standard size liners and new pistons. Will try and get the relevant pages of the Dino manual scanned.
     
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  4. Thanks Simon for the info. I have looked at the options with replacing the liners and the worry from the machine shop was that they are glued in and they need special handling to remove and replace with new ones.

    Also it looks like Lamborghini wants around 1000 UKP per liner! for these, but I think they can be had aftermarket for less (?).

    The shop I talked to was willing to bore/hone the block for around the same price and recommended we custom make the pistons + rings. In the US this appears to be around 2000-2500 UKP for the 12 pistons/matching rings and they would be made to the size of the overbore (+0.2 mm?).

    Do you have any concerns with this approach or any other recommendations?

    [Sorry I don't want to hijack your thread - we can take to PM but I think many would benefit from your wealth of knowledge]
     
  5. As yours is an LP400 there would be no issue with over-boring and going with oversize pistons, the liners on the 4.0L engines were shrunk into the block (the block was heated and then the liners dropped in), on the LP5000s they are a push fit at room temp with a spacer ring so are a bit easier to remove and replace. The shop needs to make sure they use a torque plate when doing this.
     
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  8. FYI bearing clearance is a function of the crank diameter. As a rule of thumb use 0.001 inches of diametral clearance per inch of shaft diameter. This rule works for a rotating shaft down to one inch in diameter. Below one inch use 0.001 inches of clearance.

    Cheers Jim
     
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