New starter, Barrel ID question

[freoshrew]

Hi All,

I have been sitting on the sidelines for ages enjoying the huge amount of wisdom that this forum provides, it was time to join in. Rightly or wrongly I have been collecting bits and pieces for quite a while hoping to bring them all together at some point.

I have one item that i need some help on. I was told this was an A7 Plunger Barrel, but i measured the bore and it points to what i think is an A10 Plunger Barrel, its showing over 70 mm.

Would much appreciate a pointer as to what it is (i really need a A 10 Plunger Barrel...........)

[Beezageezauk]

Hi there and welcome to the A7/A10 forum.

To answer your question I believe that you have an A10 barrel.  The give away is the number of fins.  A7 barrels have 7 fins and A10 barrels have 8.

Beezageezauk.

[muskrat]

G'day freoshrew  .
Good of you to join us.
Yes it's an A10 barrel. They came as small fin & big fin/thin flange or big fin/thick flange and either will fit plunger or swing arm motors. Standard bore is 70mm for A10's.
Tell us how you became interested in A7/10's. Did you start with a big bit?
Cheers
Beezageezauk beat me to it.

[freoshrew]

Ah brilliant, thanks for those replies, good to know its an A 10 barrel. I managed to acquire a 1952 A10 set of plunger cases and a set of 1956 A10 plunger cases, so was hoping to marry that barrel to one of them. Any suggestions, can they go with either?

How i got into A7 / A10's you ask. Ii was properly bitten by it all. They are just fantastic bits of engineering. The sound, the smell, you cant beat it.

Maybe not a great idea, i went out and bought an 1958 A7 SS, but very quickly realized i didn't have a clue how to really look after one. So i though i would go from first principals and build one (maybe three, but who's counting ) from scratch, with bits a pieces. i think the only way to figure it all out, just jump in and see where it goes. safe to say, its been a real eye opener, and learned heaps, and heaps to learn........

Its a bit random, but this is the first bit i bought.

[a10 gf]

enjoying the huge amount of wisdom that this forum provides

Great! And welcome aboard. Any tech questions welcome, in the relevant boards.

eeeh.... what's the avatar picture made of, someone sawed in two?   

[RichardL]

What I find interesting about this thin-flange barrel is that it doesn't offer access down between the fins to get to the front nut with a socket. Obviously, I didn't know that before. It is most definately a different look from the thick-flange version.

Richard L.

[duTch]

 Hola Freo, that's a good starting point ....once you get a plunger going, you'll be wanting to sell the SS  ...took me  awhile to figure that's a digital measuring stick  ... the way I read it indicates the bore is ~60thou oversize, but you need to measure halfway up (or is that down?) the bore to have a true indication of wear...you may be aware 60 is generally about the max safe oversize without resleeving, though that's been debated

 

it doesn't offer access down between the fins to get to the front nut with a socket.

 That's true, but for what it's worth, it requires a ring spanner on the other six so no point changing to a socket to do that and the two back ones, same spanner allows for consistency in 'torquing'... maybe I'm lazier than I thought...

[RichardL]

Dutch,

For my thick-flanged barrel my ring spanner will not fit between studs and fins for the nuts on the side. For the front center nut, the front engine mount (over the dynamo) prevents laying a spanner flat, so, neither a ring nor open-end spanner really fits properly. Then, if you choose to use an off-kilter spanner on that nut, you have very limited swing arc. I, for one, am happy to use a socket on an extension for that nut as well as the outer rear nuts. If I want even measured torque (which I did once, but didn't bother with for my last reassembly) I pull the ring end of the spanner with a fish scale to the force I'd calculated based on the length of the spanner.

Richard L.

[duTch]

 Fair call- I have a thin wall-low profile 1/4W ring for that, and it is a bit of a close fit

[trevinoz]

I think that you are all wrong. It is an Ariel Huntmaster barrel.

[duTch]

 Weell there yea go, I was thinkin' it looked a bit round, but thinking stopped there...

[Tomcat]

I think that you are all wrong. It is an Ariel Huntmaster barrel.

I'm impressed Trevor, and that explains the unusual shape of the fins at the rear.

[freoshrew]

Oh man, an ariel barrel! Bugger. That will be going on eBay then. I sat a round fin head on top this arvo and you know it just doesn't sit right on it, the fins at the back don't match up and it looks not quite right. Not what I would expect anyway

Thanks for all the help on this. The search is on for some a10 plunger barrels!

[trevinoz]

You could put an Ariel head on it.   

[freoshrew]

You could put an Ariel head on it.   

That's not a bad idea and one i hadn't considered as i had my BSA goggles on.