The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: freoshrew on 19.06. 2015 15:44

Title: New starter, Barrel ID question
Post by: freoshrew on 19.06. 2015 15:44
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...........)
Title: Re: New starter, Barrel ID question
Post by: Beezageezauk on 19.06. 2015 15:49
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.
Title: Re: New starter, Barrel ID question
Post by: muskrat on 19.06. 2015 15:57
G'day freoshrew  *welcome*.
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.
Title: Re: New starter, Barrel ID question
Post by: freoshrew on 19.06. 2015 16:28
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.
Title: Re: New starter, Barrel ID question
Post by: a10gf on 19.06. 2015 16:43
Quote
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?   *smile*
Title: Re: New starter, Barrel ID question
Post by: RichardL on 19.06. 2015 17:01
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.
Title: Re: New starter, Barrel ID question
Post by: duTch on 19.06. 2015 18:46
 Hola Freo, that's a good starting point *eek*....once you get a plunger going, you'll be wanting to sell the SS  *smile*...took me  awhile to figure that's a digital measuring stick  *conf*... 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

 
Quote
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'... *dunno* maybe I'm lazier than I thought...
Title: Re: New starter, Barrel ID question
Post by: RichardL on 19.06. 2015 20:35
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.
Title: Re: New starter, Barrel ID question
Post by: duTch on 20.06. 2015 00:28

 Fair call- I have a thin wall-low profile 1/4W ring for that, and it is a bit of a close fit
Title: Re: New starter, Barrel ID question
Post by: trevinoz on 20.06. 2015 01:08
I think that you are all wrong. It is an Ariel Huntmaster barrel.
Title: Re: New starter, Barrel ID question
Post by: duTch on 20.06. 2015 01:23

 Weell there yea go, I was thinkin' it looked a bit round, but thinking stopped there...
Title: Re: New starter, Barrel ID question
Post by: Tomcat on 20.06. 2015 07:18
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.
Title: Re: New starter, Barrel ID question
Post by: freoshrew on 21.06. 2015 19:36
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!
Title: Re: New starter, Barrel ID question
Post by: trevinoz on 21.06. 2015 22:04
You could put an Ariel head on it.   *smiley4*
Title: Re: New starter, Barrel ID question
Post by: freoshrew on 22.06. 2015 11:26
You could put an Ariel head on it.   *smiley4*

That's not a bad idea and one i hadn't considered as i had my BSA goggles on.
Title: Re: New starter, Barrel ID question
Post by: Butch (cb) on 23.06. 2015 08:35
Quote
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?   *smile*

I didn't twig the Arielness of the barrel, but that looks like brain sushi.
Title: Re: New starter, Barrel ID question
Post by: bikerboy on 28.06. 2015 00:52
You could also put a huntmaster rockerbox on they have an inspection cover for the push rods it dont half make it easy lol
Title: Re: New starter, Barrel ID question
Post by: muskrat on 28.06. 2015 02:36
G'day all.
This raise interesting  *????*'s As I don't know I'll ask them.
Will the Huntmaster barrels fit on the A10 cases? Will the A10 head fit on the Huntmaster barrels? Will the Huntmaster rockerbox fit on the A10 head? Are the pushrods the same?
Cheers
Title: Re: New starter, Barrel ID question
Post by: trevinoz on 28.06. 2015 22:49
Yes.
Title: Re: New starter, Barrel ID question
Post by: muskrat on 29.06. 2015 10:20
Thanks Trev  *respect*.
Cheers
Title: Re: New starter, Barrel ID question
Post by: bikerboy on 01.07. 2015 03:36
Will the Huntmaster barrels fit on the A10 cases? Will the A10 head fit on the Huntmaster barrels? Will the Huntmaster rockerbox fit on the A10 head? Are the pushrods the same?
Cheers


Yes but they aint half damned ugly :)