Author Topic: 750cc A10 ???  (Read 1270 times)

Offline scotty

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750cc A10 ???
« on: 26.09. 2012 05:09 »
The post A10 750 cc alloy barrels on e bay got me thinking  ????

Granted ,the barrels in question resemble an armadillo climbing up a suit of armour and probably should be avoided  *eek*, but,
has anybody "pumped up" their A10 from 650cc to 750cc  (alloy or iron barrels) and if so what were your experiences ?
Was it / is it worth it for the extra 100cc of raw BSA power ?
Enquiring minds are curious of the logistics of such a conversion.

Cheers

Scotty



Scotty
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Offline JulianM

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Re: 750cc A10 ???
« Reply #1 on: 26.09. 2012 08:32 »
Hi Scotty,

I am doing a big bore a10 engine at the moment so an interesting subject.
In my day job I re-design old engines to get more power and one of my hobbies that is in cooperated is "stretching" engines, In general I have found it worth every penny as torque always increases if nothing else is changed, but usually it is the start of something really good.
My engine will be either 777cc or 798cc depending on our final bore size of either 76 or 75mm,   I am doing an 88mm stroke crank for it also.  I considered 90mm but measuring up, this would have needed rather special steel rods in order to give crankcase clearance.
With a standard cast iron barrel I would not go larger than 72mm (without liners) as the blocks are terribly weak anyway.  You can through bolt them as others have done but even then i think 72 would be marginal. 
There are new blocks now available from I think Norvin, but I have not seen one and don't know if and where it has been improved.
I am having a complete new block made from billet 6061-T6 ally with much thicker walls etc and Ceramic coated instead of liners to give max strength and heat dissipation. Head bolt spacing will also need changing slightly as the bore is getting a little large for safety, even at 74mm.

Watch my build thread for updates soon.

Regards,
Julian
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Offline Topdad

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Re: 750cc A10 ???
« Reply #2 on: 26.09. 2012 13:52 »
Very interesting Julian, look forward to hearing more about this also you've just answered a post I just made re MG 's earlier post about Norvin couldn't find it anywhere will now try to track 'em down regards BobH.
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Offline duTch

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Re: 750cc A10 ???
« Reply #3 on: 27.09. 2012 11:49 »
Hey Bob This should be it..
http://www.a7a10.net/forum/index.php/topic,5915.msg40370.html#msg40370

  In a reply email Mike said they have an ad in one of the mags- maybe 'Classic Racer' or something like that..?
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Offline Topdad

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Re: 750cc A10 ???
« Reply #4 on: 28.09. 2012 12:00 »
Thanks Dutch.regards bobH
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Offline wardleybob

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Re: 750cc A10 ???
« Reply #5 on: 28.10. 2012 18:48 »
I used to put datsan cheery pistons in my a 10 not fore power for cheapness

Online BSA_54A10

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Re: 750cc A10 ???
« Reply #6 on: 29.10. 2012 05:51 »
I used to put datsan cheery pistons in my a 10 not fore power for cheapness
As a general rule it is not a good idea to use water cooled car pistons in air cooled engines as they are just not robust enough.
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Trevor