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Norton Ranger 750 cylinder head

Discussion in 'Norton P11 Motorcycles' started by Ron L, Oct 8, 2019 at 5:53 PM.

  1. Ron L

    Ron L VIP MEMBER

    Joined:
    Feb 27, 2004
    My friend has Ranger 750 serial #129144 which is one number from the purported last Ranger (129145). Looking at the cylinder head it is the "Commando" casting as all Rangers, but the rocker feed is tapped on the side of the head like Commando rather than on the top of the cylinder head as most Rangers, including mine and my spare engine. The outer bosses on the top of the head are not milled or tapped. The rocker feed oil line appears to have been replaced with a homemade one, but the original was likely the same as the early Commando.
    My spare engine is about 50 numbers lower than his and my Ranger is nearly 80 numbers earlier.
    Has anyone seen a similarly drilled head? This appears to have been done at the factory as there is no evidence that the top bosses were filled or welded. Perhaps this was a mistake by the factory that was caught before the head was completed as a Commando. He has a couple other Ranger 750's, but none with this drilling.
     
  2. norton bob

    norton bob

    Joined:
    Nov 29, 2013
    I have an Atlas 67 and the cylinder head is such a poor looking casting (compared to earlier ) that I am convinced it was rescued from the reject skip when parts ran out . Anything was possible at that period.
     
  3. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    Replacement head possibly? It seems unlikely the factory would have made an "error" due to the fact that the Norton Mercury model was about to start production at this time. First Mercury was S/N 129147 according to the Norvil m/c site, and there were a few Atlas models produced after termination of the P11 Ranger also.
    BTW, Norvil m/c has one of these late 650 heads for sale (raw casting number 06-0380) which displays oil feed at the top. There are also pictures of Mercury bikes confirming this.

    -Knut
     
  4. Ron L

    Ron L VIP MEMBER

    Joined:
    Feb 27, 2004
    It's a possibility, but I would have expected the outer bosses on top of the head to be milled and tapped if the replacement was a Commando head. It clearly is a mixture of Commando and Atlas/G15/P11 milling/tapping. Just another mystery.
     

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