CHOP CULT HOME
Email Password
Search
  1. #1
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Apr 2013
    Posts
    9,458

    Default B-29 engine fires, steel crankcases and interesting base flange nut washers.

    https://www.cycleworld.com/story/blo...ion-explained/

    Pratt & Whitney radials, which have forged-aluminum crankcases, retain their cylinders by studs and nuts. On the other hand, the cylinders of Wright’s big engines are retained by bolts which screw into the steel case—21 individual 7/16 NF bolts per cylinder. The late John Minnich, a Wright engineer during the war, told me that at the level of the intake port, just over a foot away from the cylinder’s upset-forged steel base flange, rod angularity at each firing caused the cylinder to kick sideways by twenty-thousandths of an inch. Because of that flexure, each base bolt sat on a part-spherical washer, fitting into a matching cup in the base flange. Without this feature base-bolt breakage was constant. Everything was constantly flexing. Try to imagine magnesium threads surviving such motions.

  2. #2

    Join Date
    Dec 2018
    Posts
    2,081

    Default

    And it is my contention that evo base gaskets leak because the rather tall cylinders rock back & forth on the very narrow base, and disturb the gasket. Earlier motors had larger base flanges, and did not have this problem.

    Jim

  3. #3
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2014
    Posts
    1,523

    Default

    That article was outstanding. I didn’t even know Kevin Cameron was still writing.
    The guy is brilliant.

  4. #4
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2014
    Posts
    1,523

    Default

    Quote Originally Posted by JBinNC View Post
    And it is my contention that evo base gaskets leak because the rather tall cylinders rock back & forth on the very narrow base, and disturb the gasket. Earlier motors had larger base flanges, and did not have this problem.

    Jim
    It is my contention that I drink more alcohol to ignore my tranny main seal leaks and cure them with more oil added to balance the system back out as well as my own mental health.

  5. #5
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Sep 2014
    Posts
    1,523

    Default

    It is also my contention to say that I believe if Harley would never heve foolishly improved the total loss oiling system , i would never had to explain the oil spots left on someone else’s driveway.

  6. #6

    Join Date
    Dec 2018
    Posts
    2,081

    Default

    It is my contention that a drip indicates that there is oil in the gearbox.

    Jim

Share This



Posting Permissions

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

Log in

Log in