Author Topic: Can A65 pistons be fitted to an A10 as direct replacement ?  (Read 2222 times)

Online Triton Thrasher

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BTW, did you guys read the small print on Bird's custard lately?

Does it no longer contain birds?

Online morris

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Does it no longer contain birds?

Well... yes but no but yes but of German origin...
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'52 BSA A 10 Plunger
'55 MORRIS ISIS
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Online bsa-bill

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a wild guess - "contains eggs"
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online morris

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a wild guess - "contains eggs"
Still no eggs. But entirely made in Germany with German milk... *shh*
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

Online bsa-bill

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Quote
entirely made in Germany with German milk..
They have no cows over there then *smiley4* OOPs another wedge in our relations with Europe

   Beriano - you must be wondering what on earth is going on, however the first answer to your post was really  definitive
Keeps us informed of your progress and pics
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Topdad

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good morning Morris, just read your post re chips egg and pickled onions plus ample doses of sauce mayo and speckled hen , I 'm not confused ,just grateful for the input if/when we meet i'll remember to stay well "UP WIND " from you!! if you order that .  *smile* *countdown* many thanks for the moderators leyway with this off topic banter ,cheers Bob.
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Online muskrat

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If you could fit A65 pistons in an A10 it would make about 750cc. A A10 crank in a punched out A65 can get about 900cc *eek* *work*
Cheers
 *shh*
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline Rocket Racer

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I,m new to this forum,following a recent con rod failure on my '48 rigid framed A10 (1950 engine) I am in the process of gathering bits for my rebuild. In this connection I have acquired A large journal crank and already have a spitfire cam if needed and also have thick flange barrell.New A10 pistons tend to be much more expensive than A65 pistons, as I intend to increase the compression can anyone advise if the A65 pistons will work as direct replacements.?.....many thanks in anticipation of a reply (hopefully)

Photos would be nice!
now given a thick flange barrel is big fin, you also mention a sports cam...what state of tune are you aiming for? Keeping the iron head?
Cake Street Classics certainly used to stock wiseco pistons.
I personally avoid JP's like the plague.
I had a ride on a mates cooking '55 flash on New Years Day, delightful. Smooth as. Not a go fast bit to be found on it. Quite a different beastie to my methanol twin carb track bike, but no worse for it.

A65 pistons not an easy solution, the stock flanges don't have enough meat in them to go beyond 72.5mm
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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Offline Gerry

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Hi Guys, JP pistons and rings are made here in Adelaide and sold all over the World. Haven't bought any myself from them but have purchased rings from them over the counter. Cheers. Gerry

Offline Gerry

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Hi again, Here's J P Engineering web address - http://www.jp.com.au/JPPistons.html  Cheers. Gerry

Offline Rocket Racer

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Thanks to a very wicked fellow forum member  *wink2* I've just bought some suitable pistons for my a10  *yeah*
certainly not under a 100 quid though

Can't wait to try these out   *respect*
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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Online Brian

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I had a look through my books and while I couldnt find 67-554 I did find 67-1554 which are 8.75-1 pistons. Looking at the tops of the pistons I think that would be about right.

I'm still searching but somewhere among my info I have listings for BSA pistons that go up to 14-1. I will find it sooner or later.

Online RichardL

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Brian,

I saw the listing from which RR bought these pistons. Seller was listing as 14:1,  which makes more sense to me than 8.75:1. My little dome-tops are considered 9:1 and there is a lot more piston above the top of the bore with these. I am assuming RR was looking for high compression, after all "R" number two is for "racer". (RR, I'm not trying to talk for you.)

Richard L.

Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020. This year it's a solo or pillion ride in dapper attire. Watch website at https://www.gentlemansride.com for details.


Online Brian

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The pistons in the picture certainly do appear to have high crowns but the valve recesses are shallow so I think the gudgeon to crown height is low. Maybe someone can identify the number on the top more accurately.

Offline Rocket Racer

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553 or 555 are 14:1 have yet to find ref to 554, but assuming they are 70.5 they look more dramatic than a set of 10.5's so I'm hoping they are as advertised 14:1 methanol pistons  >:D
Which should be very interesting...
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand