The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Lightningpower on 12.11. 2015 00:39
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I looked for a while and found nothing before I posted this, so I hope this hasn't already been done.
Is it possible to build a comprehensive photo and spec. based identification thread for iron A7 & A10 heads? There seems to be several types out there, including Ariel ones, to lend a bit of confusion. Atlanticgreen has that great page concerning alloy heads, but he never finished the iron head section.
I cannot easily identify iron heads. Would anyone be willing to post post pics and measurements, with casting numbers and part numbers?
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G'day Lightningpower.
Here's the part #'s to get you started.
A7 1947-50 = 67-24, 1951-53 = 67-380, 1954 on = 67-1061
A7ST 1949 = 67-182, 1950-51 = 56-524, 1952-54 = 67-1063
A10 1950 = 67-250, 1951-53 = 67-1065, 1955 on = 42-0180
Casting #'s are one less than the part #. Small fin up to 53, large fin 54 on.
Cheers
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Ariel Huntmaster heads are compatible with the A10, the only thing with those you have to put huntmanter exhaust pipes on as they are set at a different angle. are flanged.
Regards TTJohn
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That's a help. Thanks. Does anyone know what the part / casting numbers are for: Ariel Fieldmaster, Huntmaster/Cyclone, and BSA Super Flash?
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According to my information the 67-1065 head was introduced with the swinging arm in 1954, the 42-0180 was introduced in 1960 with the new part number to coincide with a bigger inlet tract and a 389 carb. I've never seen a 42-0180 head stamped as such. There was a thread on this issue a while ago as I was interested in the 42-0180 upgrade. I don't think anybody on the forum at the time had a head stamped 42-0180 (or 0181) so the conclusion drawn was that all the later square heads were stamped 1066 but the later ones had a bigger inlet tract. Check this..... http://www.a7a10.net/forum/index.php?topic=9916.msg72822#msg72822 (http://www.a7a10.net/forum/index.php?topic=9916.msg72822#msg72822)