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Leak Down Test (Don't Laugh!!)

Discussion in 'Norton Commando Motorcycles (Classic)' started by click, Jan 27, 2018.

  1. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Thanks for the oil recommendation.

    Only joking about the oil testing:) I can only imagine how busy you are in your workshop!

    From the video you posted there is some racket from the oil testing rig, look after your hearing!
     
  2. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    I knew your weren't serious.
    But some people don't realize this.

    The noise is not nearly as loud as the camera makes it sound.

    By the way, your parts did ship today.
     
  3. Deets55

    Deets55 VIP MEMBER

    Joined:
    Oct 3, 2013
    Jim,
    It’s pretty obvious that it took a lot of work to get click’s bike up to 880. I was courious to know if you start with a good engine at standard bore how much work would it take to get to 880 instead of going the 920 route using readily available parts (if these parts actually exist)

    Pete
     
  4. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    Click's project was more work because it was already a 920 with oversized wrist pins.
    Fitting the big wrist pins into the readily available JE 880 pistons was not a job I will be doing again.

    The 880 kit requires sleeves in the cylinders. The 880 sized bore is the largest I would use if you are looking for durability.

    The JE pistons for 880 bore are readily available. They come with the problems created by a high expansion forged piston in an air cooled motor.

    I can also get 4032 billet pistons on a special order basis. They are much more forgiving than the 2618 alloy pistons.

    Before I would spend the money for a big bore kit I would do a cam and big valve conversion. You will get a lot more bang for the buck.

    The power increase from a big bore kit without improving the breathing is very small.
     
    Schilling likes this.
  5. Deets55

    Deets55 VIP MEMBER

    Joined:
    Oct 3, 2013
    Jim,
    Thanks for the info.
    Pete
     
  6. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Great, thanks for the update.
     
  7. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Another minor update:

    Got the barrels and pistons/rings from Jim.

    I've cleaned the barrels as per Jim's instructions. Clean with soapy water, let dry then wipe with kiitchen cloth & engine oil until no more black marks on kitchen cloth.

    Fair amount of black 'stuff' on the cloth, took 3-4 rubdowns before the cloth was clean.

    Next stage is to make a board for holding the barrels, fit the rings to the pistons, fit pistons into the barrels then fit the barrels/pistons to the conrods!!!

    I know you guys like pictures so here's a very exciting picture of some buckets of hot soapy water & the barrels:)

    Cleanbarrels.jpg
     
  8. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Need help already :rolleyes:

    OK, I have the JE pistons & rings. I've gone to their site & looked at the install rings info. but it's not really helping!!

    There's 3 rings, ones black, ones a copper colour & the 3rd is the 3 part oil ring (see pics below)

    Does anybody have any better install instructions? For instance which one is the top ring, black or copper.

    They both have N50 on them, see pics below, do these face up?

    Also any help with the 3 part oil ring would be appreciated, especially any pics of a set installed.

    What else would anybody be doing than helping me on Xmas eve!!!

    By the way Happy Xmas to one & all on this forum and a very Happy New Year :D

    IMG_3984.jpg IMG_3985.jpg IMG_3986.jpg IMG_3989.jpg IMG_3988.jpg IMG_3987.jpg
     
  9. cliffa

    cliffa

    Joined:
    May 26, 2013
    Mmmmmm, Soapppy waaaaaatttter :oops:


    Happy Christmas Click !!


    Cheers,


    cliffa.
     
  10. Dommie Nator

    Dommie Nator VIP MEMBER

    Joined:
    Apr 2, 2013
    I had these instructions with mine.
     

    Attached Files:

  11. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Fantastic, I didn't have any instructions!, that explains which one is the top compression & which one is the 2nd scraper.

    Appreciate the help :)
     
  12. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Dont get tooooooo excited:p
     
  13. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    Copper colored is the top
    Black is the second
    Numbers, letters or dots always face the top of the piston.
    Install the oil ring with the side rails staggered one inch on either side of the expanders end.

    Merry Christmas!!!
     
  14. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Thanks Jim, have a good Christmas break.
     
  15. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
  16. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    Thought I had a few base gaskets in stock but I gave them to a mate over a year ago who was rebuilding his motor, he was suppose to replace them!!

    By any chance if anybody from Ireland is reading this and has an 850 base gasket lying around drop me a PM.

    I'm going to order some gaskets from the UK but I probably won't get them till 8/9th Jan!!

    I know there's different opinions about using a base gasket or not but the motor had one fitted so I just want to replace like with like.
     
  17. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    You don’t need it. Or more correctly, it should not be there on an 850.

    Putting it in just because it was there before is a strange logic matey... you’re not putting the other ‘errors’ back in are you!?

    Putting one in will only lose you a little bit of CR, that’s all.

    I’d press on without it.
     
  18. click

    click VIP MEMBER

    Joined:
    Dec 27, 2008
    I know we are talking about a very minor clearance difference between using & not using a gasket but could I have any issues with pushrods/tappet clearance etc? Sort of know the answer, just want to be sure!!
     
  19. Geoff Lather

    Geoff Lather

    Joined:
    Nov 18, 2018
    Its my soap and its my penis and I'll wash it just as fast as I like.
     
  20. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Be sure about what Click...? The 850 DID NOT HAVE a gasket from the factory. So, unless your pushrods have been shortened to accommodate the thickness of a gasket by the previous builder (rather unlikely I’d suggest) then by your own argument, you’re better off without one...!

    Jus’ sayin’...
     

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