The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: uglyfrank on 24.06. 2010 04:46
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Hello forum, I am happy to be part of this information forum on behalf of a crusty BSA owner/lover who has no access to cyberspace.
I/we hail from Healesville, Victoria, Australia. We are about 60 Kilometres east of Melbourne. The question is from my friend Taffy John. He has an iron head from a Road Rocket / Super Rocket, that he is trying to establish identification. His question is to do with the size difference of the inlet and outlet valves on the over standard size head. Is there a difinitive answer to this question regarding the size difference to the valves. I thank you, on Taffy's behalf, if there is someone who understands the question and can suppy the answer
Regards, Uglyfrank.
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Hi
If its an iron head its going to be off a Golden Flash. Rockets had alloy heads.
I dont understand what you mean by "over standard sized" head, but there were two sizes, the first known as "small fin" went on engines upto 1950 [I think]. Then BSA changed design and made the fins bigger, that was the size thru to the end. - maybe you have the large finned one.
The in / ex valves in the Flash were the same size, but the ex valves had a different material on the valves head.
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Hello and welcome to the forum!
In case it is a Rocket (alloy) head, lots of information can be found here:
http://atlanticgreen.com/a10alloyhead.htm (http://atlanticgreen.com/a10alloyhead.htm)
Cheers, Markus
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G'day Uglyfrank, welcome,
are there any casting numbers on the head ? This will help id it.
Can I call you fugly for short. *smile*
Cheers
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Hello once again all,
Thank you A10 Boy, MG and Muskrat for the useful communication. I am still feeling my way around this enlightening forum, so please forgive any inadvertent fopars. This head issue will be a steep learning curve for me in regard to the bike and also for Taffy and the computer. All information I will pass to John and we will eventually find the information he needs to continue with this love project. A picture may help in identification (which I will get and post) as well as and stamped numbers that I will provide if the link supplied by you MG draws a blank. So, onward to Taffy and glean more information and then return to add more pieces to this puzzle. I will try to make all things understandable in the level of information so together we solve Johns problem. Thank you once again Gentlemen and yes Muskrat I would be chuffed with fugly. Go Saints !!
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Hello forum family,
Taffy and I have done some more investigation about the head from his BSA. Current info is this.... the head is an alloy 650 head.
The serial number stamped on the head is 67-1126 with the letters AM stamped close by. The measurement across the flat of the barrel's width is 26cm. So if this information can help identify the size of the valves that may be being used are bigger than the standard sizethat is comonly used, then that would solve Taffy's dillema. The thought has just occured to me, and this will sound pretty silly, but I suppose if we can get measurement of the valvue in the head at the moment that would go a long way to determining if they are bigger or smaller than the commom size, yes?.
In the meantime; Thank you all for your help so far in this question and we look forward to finding an answer in the near future.
Regards and thanks on behalf of Taffy,
Uglyfrank
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G'day fugly, *smile*
Check out this site http://atlanticgreen.com/a10alloyhead.htm your's is either a '56-'57 Road rocket or '58-'59 Super rocket.
Cheers
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Here are details of BSA club of Victoria there should be someone near you to have a chat to for advise.
cheers Terry
http://www.bsa.asn.au/html/club/contacts.html