Newby from Perth (Oz) seeking A10 guidance/greatness

[BSA_Owen]

Hi All!

new to the forum and also new to A7/A10's although have always loved the look of the engines.

I am currently building a little A10 rigid chopper and need some help with sorting out my engine and gearbox parts, the bike is entered in a "build off" of sorts and I am rapidly running out of time.

Anyhow here's a pic of the mock up. It's an original rigid frame with semi unit A10 motor in bad shape. I have an alloy head I want to run (ideally if a complete A10 engine appeared in good condition in WA that would save some heart ache for me here)

anyhow thanks for letting me join and expect a fair few questions coming from me as I dive deep into the abyss.

-Owen-

[a10 gf]

have always loved the look of the engines

Yes !
Welcome aboard.

[scotty]

Welcome Owen

Nice looking rig you have there

Hours of fun

S

[muskrat]

G'day Owen. 
We have a few members over on your side who may be able to help. Put questions in the appropriate section and you'll get world wide response.
There is the odd (pun intended) member with a chopped A7/10.
Cheers

[duTch]

 Howdy Owen- good luck with it, should give many hours of fun....I grafted an ally head on my Plunger A10 but running a 389 Mono with air filter proved something of a challenge,  but that can be addressed in an appropriate topic if need be 

[Greybeard]

 

[Jules]

Hi Owen, should be a great looking machine when done, please post up when finished, but I reckon you'll need ear muffs with the megaphones so close to your head lol 

[WozzA]

Welcome Owen...  it looks like it's a early long stroke motor, with '56-'57 Ariel type hubs,
everything you need to complete her should be available, & I'm sure you'll get plenty of good advice from our experts on this forum. 

[muskrat]

G'day again Owen.
It looks like an early A10 motor to me.
Can't work out what is between the head and monoblok carb.
An alloy head will fit but the clearance for the cables is restricted, due to the more downdraft inlet manifold (carb sits higher).
Cheers

[Swarfcut]

Woz..It's a trick of the light. Early thin fin barrel, single piece rockerbox,  dynamo end of the timing cover pointing slightly upwards (Longstroke is flat). It is an early A10 type.

 Between the carb looks to be some kind of adaptor tract, directing the inlet to the left hand side of the frame tube. More style than function, but that's part of the charm of this sort of build.

 The bad news is that Owen's Alloy head won't match the thin fin barrel. It will fit as regards the holes, but will overhang the barrel, and as musko says, space around the carb may be a problem.

 Owen, Hi, Welcome, Nice Pipes!

Swarfy.

[BSA_Owen]

Thanks all for the warm welcome!
There is indeed a swept intake adaptor fitted which will give a bunch more room around the frame to fit the carb and cables.

The inner primary part of these cases is damaged but I have another set that are good. Barrels have a broken fin so I’m hoping I can replace. It’s all very new to me though as to what will work.

 I’ve just finished my m20 girder framed telescopic fork b33 powered other bitsa so this build is following a similar method of making things work together.

[muskrat]

G'day Owen.
If your going to replace the barrels I'd suggest looking for large fin (and thick flange). Aussie heat and small fins don't go well together (not the way I ride  ). The alloy head would then match.
My 51 plunger A7 has 57 SS large fin barrels and alloy head.
Cheers

[BSA_Owen]

cheers Musky,

Wasn't sure if all barrels work on the plungers but I guess they do!
I should be able to pick up a set from the local bsa guy. I guess this would sort the comp ratio also if I use later barrels and pistons to suit the head?

[WozzA]

Yep a early A10 it is...   I thought it had the 3 piece rocker cover on her.. 

[duTch]

 

........  I thought it had the 3 piece rocker cover on her..  .

  ...I always thought they a two piece ??

 Owen, I'm also running thick flange/big fin barrels with flat top pistons pin my BA engine and generally runs fine... and ally head- I be interested in a close up of that inlet tract adapter- you show my yours and I'll show you mine