Author Topic: Looking for Mk3 Barrels, Pistons etc..  (Read 2981 times)

0 Members and 1 Guest are viewing this topic.

Offline Benny

  • Member
  • *
  • Join Date: Jan 2012
  • Posts: 6
  • Location: Melbourne, Australia
Looking for Mk3 Barrels, Pistons etc..
« on: 23 Mar 2012 at 12:48 »
Hi Everyone,
I'm looking for Mk3 Barrels, Pistons, etc... to eventually convert my Mk3 (which has MK1 Barrels etc...) back to original.
It runs and performs great as is but would love to have them there to do, down the track.
Anybody know where I could get a Mk3 setup?.
I've just joined the London Douglas Motorcycle Club. Would they have any parts to suit?
Thanks,
Benny.

Offline David Lawrence

  • Senior Member
  • ***
  • Join Date: Sep 2011
  • Posts: 166
  • Location: Essex UK
Re: Looking for Mk3 Barrels, Pistons etc..
« Reply #1 on: 24 Mar 2012 at 21:35 »
Hi Benny,
Glad to here you have joined the London Douglas Club, as you are probably aware good barrels have been very scarce, such that the Club is in the process of making new ones, the first test castings are at present being machined, hopefully the production should be underway shortly, regarding pistons, these occasionaly become available but are scarce and the Club is awaiting quotations to manufacture pistons to the original specification albeit using the more modern low expansion alloys. Sadly production costs make both these items quite expensive but hopefully they will last forever!!
You do not mention if the conversion of your engine is fitted with early Mk1 heads, these are not  suitable on the later model, however if this is the case and you cannot source any in Australia we do have one pair of very good second hand ones in spares. I am not sure how familiar you are with the mark series, but if not sure the early heads have a more rounded rocker cover with the word DOUGLAS cast into it, later types are more kidney bowl shaped with no name.
Should you wish for further information please feel free to email direct.
Dave

Offline Benny

  • Member
  • *
  • Join Date: Jan 2012
  • Posts: 6
  • Location: Melbourne, Australia
Re: Looking for Mk3 Barrels, Pistons etc..
« Reply #2 on: 14 Apr 2012 at 18:52 »
Hi David,
Thanks for your reply. I look forward to the clubs reproduction of barrels.
I do have mk1 heads. It appears my mk3 has been fully set up with mk1 heads, barrels etc...I have not checked the pistons as yet but figure they'd be the high crown mk1 type.
It runs well but I think it may better converted back to original spec.
Any parts you may have to help me towards this I would be very thankful for.
Please let me know what is available and how I may purchase them from the club.
Cheers.
Benny.


Offline David Lawrence

  • Senior Member
  • ***
  • Join Date: Sep 2011
  • Posts: 166
  • Location: Essex UK
Re: Looking for Mk3 Barrels, Pistons etc..
« Reply #3 on: 14 Apr 2012 at 21:02 »
Hi Benny,
I think you are probably correct and the whole of the top end is Mk1 with the high domed topped pistons, the only parts suitable may be the actual cam followers assuming they are not worn. The Club has most of the rest of the parts you would require. I will email you directly in a few days after I check availability and prices with Patrick our post war spares man. I will need to check with those that know if the rocker blocks are interchangeable as the valve arrangement is different. It would be interesting to know if the carbs were later alloy type, some mark 1 models had all brass carbs, but they should be interchangable.
Cheers for now.
Dave

Offline eddie

  • Master Member
  • ****
  • Join Date: Mar 2006
  • Posts: 1655
  • Location: Hampshire, UK
Re: Looking for Mk3 Barrels, Pistons etc..
« Reply #4 on: 14 Apr 2012 at 21:15 »
Dave, Benny,
                   I think you will find the bronze rocker blocks are the same on all Marks, but the rocker arms are different on the Mk1's as the valves are set at a wider angle in the deeper heads.

  Benny,
            Regarding your other posting about the exhaust system - you can change the whole system over to the later Mk5 type with long pipes and barrel silencers, but you may find your machine has the wide type centre stand which will foul the silencers. I think you should be able to get a new narrow stand from club spares.

    Regards,
                 Eddie.