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Identifying Heads & Barrels

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  • Identifying Heads & Barrels

    I have two 32A/34A-type heads and iron barrels. One, off my 24TE, has the spark plug on the right, with corresponding provision for a decompressor on the left of the head. The other has the plug at the rear of the head.

    My questions are, what is the second head off, and how can I tell the difference between 32A and 34A heads and barrels?

    Many thanks. Ian

  • #2
    To start with the 32A (road & trials) has a compression ratio of 7.9:1 & the 34A (scrambles) is 12:1 so will have a much smaller combustion chamber. As for configuration of heads, the 32A was used in a variety of applications, roadsters, trials, Bond mini cars, invalid carriages etc so the position of plug & decompressor can vary. I think most motorcycle applications had the plug towards the rear.
    As for barrels the 32A has a cut away where a separate Villiers S25 carb manifold bolts on, the 34A has a flange fitting for a 389 Amal carb. The size of the ports in the 34A will be larger.
    There were also other Marks ie 31A (7.4:1 comp) 33A & 36A (12:1 comp) & 37A 7.9:1 comp) which may have had different head configurations, so your heads may have come from one of these

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    • #3
      Ok John, thanks for that. The head and barrel off my 24TE are fine, it was the other 'set' I wasn't sure about. I will study the barrels, but at a quick glance they are the same, so 32A in all probability. The head with rearward facing plug is pretty damaged inside; I guess a piston or rings let go at some time; so needs welding up and machining a new combustion chamber. I seem to remember reading on here about doing just that, creating a top hat shaped combustion chamber with a wider squish band. I will do a search to see if I can find it, then do a search locally to find someone who can do it! Unless there is a clever welder on here who I can send it to, to do it for me....

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      • #4
        Originally posted by IanCordes View Post
        I have two 32A/34A-type heads and iron barrels. One, off my 24TE, has the spark plug on the right, with corresponding provision for a decompressor on the left of the head. The other has the plug at the rear of the head.

        My questions are, what is the second head off, and how can I tell the difference between 32A and 34A heads and barrels?

        Many thanks. Ian
        On the heads look for the number cast between the outer small fins on each side or stamped near the cylinder joint. On the barrels cast below the fins should be a number.Then check with the parts books.eg 31A barrel is C11588 heads B11910 is 33-34-36A 11765 is 31A/4SR

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        • #5
          Originally posted by IanCordes View Post
          I guess a piston or rings let go at some time; so needs welding up and machining a new combustion chamber. I seem to remember reading on here about doing just that, creating a top hat shaped combustion chamber with a wider squish band. I will do a search to see if I can find it
          The welding & re-profile of a cylinder head was by Rob in LL184 Aug 2015
          & LL185 Oct 2015 under the heading Anglian Improvements

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          • #6
            Thanks Stuart. I will have a look.

            Thanks again John.

            Ian

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            • #7
              Hi Ian ,the Villiers head in L/L 184 page 33 is the one Alan Nicklin modified for me he also did some work on the barrel as well , the difference to a standard head and barrel (32A) in performance is vast , also a good exhaust and silencer are a must , ask Dicky Faggetter he wanted to swop his Anglian for my TE .In the next L/L there should be an article on my bike with this head and barrel on .Couple of photos of head.
              Simon
              Attached Files

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              • #8
                Hi Simon. My spare head is the same as yours, or at least as it was, so a suitable candidate. Having just acquired a 20DC roadster, already I am thinking it needs more power. I could get 1/4" machined off the bottom of my spare 32A barrel, to up the motor to 250cc, then modify the head as per yours and Rob's. As you say, to capitalize on it some porting work, and a good exhaust would be needed. I don't want to change the exhaust on the roadster, so would have to accept the limitations. However, whilst I can swap the parts over, I can't do the welding or the machining, and 2-stroke porting is a black art to me! Where is Alan Nicklin located?! I will look out for your article in the next L/L.

                Cheers. Ian

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                • #9
                  Ian have sent you a PM . Simon

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