+ Reply to Thread
Results 1 to 3 of 3
  1. #1
    Registered Member
    , ,
    Member No: 60863 skim3544 is an unknown quantity at this point skim3544's Avatar
    Join Date
    Dec 2002
    Rep Power

    Yes | No

    M20 2.7L engine rebuilding

    Question about rebuilding Super Eta M20 engine.
    The Standard bore is 83.98mm, and I am thinking about boring out to 84.48mm.

    1) Where can I purchase the parts (Pistons, rings, gaskets,...)? Which brand of Piston is good (Mahle, KS, Maxsil,...)

    2) Would I need some type of high flow water pump after this conversion?

    3) Would I need a special head gasket (because cylinder size is larger)?

    4) what kind of performance enhance can I make while I am in there.

    thanks in advance

  2. #2
    Matt Hernandez
    , ,
    Member No: Matt Hernandez's Avatar

    Yes | No

    Re: M20 2.7L engine rebuilding

    1 wayyyyy too expensive, id just stick with stock pistons and get new TOTAL SEAL rings through top end performance for the 325i. You wont even feel the difference, the only reason the car will be faster is because your wallet is lighter. The cost to benefit ratio of oversize pistons on these engines is negligible. Stick with MAHLE or JE Pistons

    2 you dont need one, aftermarket is not available

    3 if you DO get larger pistons the headgasket needs to be purchased if they even sell them for a larger bore or you can modify an existing headgasket.

    4. ireland engineering billet camshaft, get a 272 with half a mm more lift. Cam is 325 plus shipping

  3. #3
    , ,
    Member No: TJ's Avatar

    Yes | No

    Re: M20 2.7L engine rebuilding

    1) well if you're going to buy new pistons then you might as well get oversize. Unless you know where to get cheaper off-the-shelf stock ones. But I called a couple of places about super e pistons and their price was higher than what I could spend getting a set of light-weight, forged pistons custom made (guess what I picked...)

    2) actually the eta engines use a larger crank pulley than the 325i so the water pump is driven at a higher speed if you're using that. Not sure if it's really helpful to have, it might just cause extra wear (to the pump) on a higher-revving engine.

    3) If your overbore is only .5mm then the stock gasket is fine. But Metric Mechanic offers M10 head gaskets for larger overbores so they might have something for the M20 also.

    4) change the cam like Matt says, and be sure to upgrade from the super eta valve springs and intake to the 325i ones

+ Reply to Thread

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)



Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
1e2 Forum