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Head gasket time

Discussion in 'Norton Commando Motorcycles (Classic)' started by Danno, Apr 1, 2019.

  1. Danno

    Danno

    Joined:
    Feb 7, 2010
    The SS clone's head gasket is starting to weep, so I think I'll replace it before it get worse. It's been 35 years but not a ton of miles since I buttoned up the engine after a rebore and new valve guides.

    I ordered a flame ring gasket from Old Britts and received a 1MM thick example. I thought the 2mm was considered they way to go, less prone to blowing.

    Got Jury Duty this week and I'm gonna use my juror pay to get a set of those elastic fluted head bolts from CNW. Also thinking about some beehive valve springs and slippery fork bushings from JS. One Q?; Are the 3 bronze thread inserts required to use the elastic bolts?

    Edit: Just read it was the .75mm gaskets that were superceded by 1mm, so I should be good with what I have.
     
    Last edited: Apr 1, 2019
  2. Hortons Norton

    Hortons Norton

    Joined:
    Oct 12, 2007
    Now that's funny! last time I did jury duty I think they paid $5.00 a day. Have the price on the CNW fasteners gone down?? Good one.
     
  3. ashman

    ashman

    Joined:
    Jul 11, 2010
    Have you tired retensioning the head down, if its only a small weep it might just need retensioning.

    Ashley
     
  4. Danno

    Danno

    Joined:
    Feb 7, 2010
    Everything's torqued to spec. Upon assembly, it was torqued, ran for a few miles and then torqued again while hot. Copper gasket was annealed and sprayed with aluminized silver paint. The weep is at the rear of the head/cylinder junction, likely starting at the oil drain hole. I wish I had included the fine copper wire around the cylinders, oil drain and pushrod tunnels.
     
  5. ashman

    ashman

    Joined:
    Jul 11, 2010
    I am picking up a 750 Commando today for a member Alan his head gasket is leaking, motor was rebuilt 5 years ago has a PW3 cam installed but hasn't been retorqued since that I know of so will give it a good clean tomorrow and retorque the head and see if its lost it tension it has a copper head gasket fitted, but if it still leaks after a ride the head will come off for new head gasket, he also has another oil leak somewhere that I will chase up for him and fix.

    Ashley
     
  6. Danno

    Danno

    Joined:
    Feb 7, 2010
    Well, I didn't get picked, so only one day's pay ($5?) + 16 miles mileage. Might be able to buy a couple of beers.
     
    Hortons Norton likes this.
  7. Danno

    Danno

    Joined:
    Feb 7, 2010
    Still wondering about the bronze thread inserts.
     
  8. gortnipper

    gortnipper VIP MEMBER

    Joined:
    Nov 11, 2013
    Are you talking about the three studs internal to the head or the four bolts next to the plug holes, as the waisted bolts I have from comnoz are those four. And they dont need the inserts, as the threads are the same.

    I think the three black internal studs do need the inserts, as the thread pitch is different than stock. But, they are not waisted.
     
  9. Jdub

    Jdub

    Joined:
    Dec 1, 2018
    Slightly off topic, but aren't our heads to be re-torqued cold?
     
  10. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 25, 2004
    I
    I am wondering the same thing, as the last time I did the hot torque I compressed the composite gasket down to nothing and it leaked, I think the torque will be too high if retorqued hot?
     
  11. Steves

    Steves

    Joined:
    Oct 16, 2016
    Mick Hemmings recommends using Wellseal with composite gaskets. Let it go tacky, retorque after 50 miles. I went this route recently. But as they say more than one way to skin a cat
     
  12. Danno

    Danno

    Joined:
    Feb 7, 2010
    Then the only waisted fasteners are those 4 outers? What about the center bolt?
     
  13. Danno

    Danno

    Joined:
    Feb 7, 2010
    Shouldn't be too high as long as you don't exceed the recommended number. I think checking it after heating the motor up is just a precaution in case something moves and loosens a fastener. Sure works on exhaust nuts.
     
  14. gortnipper

    gortnipper VIP MEMBER

    Joined:
    Nov 11, 2013
    I
    Pass.

    Jim waisted mine for free right when CNW made the shift in their kits, and I had recently bought a set that were unwaisted.

    IIRC, it was just those four, but a note to him or Matt would confirm.
     
  15. blaisestation

    blaisestation

    Joined:
    Apr 10, 2008
    cylinder heads should not be torqued when hot ! I always leave mine to sit overnight before checking any torque measurements ,or setting valve clearance etc.
    torqueing (spelling ?) an aluminium cylinder head when hot is asking for trouble.
    only my own humble opinion.
     
    Last edited: Apr 3, 2019
    kerinorton and Fast Eddie like this.
  16. Hortons Norton

    Hortons Norton

    Joined:
    Oct 12, 2007
    Purchased these to possibly give them a try? I have used these on my Buell but have no idea how they will do on a Norton. What have you found?? They look very well made.

    [​IMG]
     
    nortriubuell likes this.
  17. Bob Z.

    Bob Z.

    Joined:
    Mar 30, 2012
    Looking forward to your comments after installation. They look good in black.
    Why just one exhaust valve cover gasket?
     
  18. Danno

    Danno

    Joined:
    Feb 7, 2010
    Cometic has a pretty good reputation. 1.1 mm flame ring head gasket. If 1 mm is better than .75 mm, is 1.1 mm better yet?
     
  19. Hortons Norton

    Hortons Norton

    Joined:
    Oct 12, 2007
    Good question, I asked for a set and this is what they sent. Maybe the guy cutting them didn't know.
     
  20. oldbeezer

    oldbeezer VIP MEMBER

    Joined:
    Nov 2, 2017
    looking at the invoice it appears just 1 exhaust was ordered.o_O
     

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