Britbike forum Forums British motorcycles in general British motorcycles in general Scrap barrel or can it be saved?

I was looking at getting a set of iron OIF A65 barrel (71-1033) bored and whilst trying to work out their current oversize, noticed some marks in the bore. Turns out this mark is also visible on the outside, below the bottom fin and the flange. As it stands you couldn’t reliably bore it and expect all to be ok.

Before I send it to the gods of vintage BSAs, is this Repairable?

I’m thinking have the area welded, then have the bores sleeved. Or is this just like playing Russian roulette?

I’m happy either way, I know for what the work would cost I could get another barrel for that amount. I’d have been much happier this being a good barrel of course. But sadly I don’t have that luxury.

Scrap, not worth the trouble. They are plentiful enough.

I've gone through the exercise of through bolting and lining a barrel before
but it's a lot of work or expensive if you farm it out.
Once the wall thickness is small they loose strength so need through bolting,
that has to be done carefully as it is on an angle.

EBVC has a +20 on ebay at the moment, better to get that bored than mess
about repairing the one you have.

Thanks Nick, That’s what I was leaning towards. Though didn’t want to think I’d scrapped something that could have been an easy fix. I was more surprised how it hadn’t cracked completely and put pay to the end of a complete motor. I guess the PO noticed an oil leak or something and whipped the barrel off.

I’ve got a few scrap casings and some other bits which I’ll mock up as an engine.

My first A10 had a crack like that ( from a jamed rod ) that eventually ran completely around the flange allowing the right side to lift about 1/4" each stroke
Which caused the muffler mounts to break and the muffler to swing out & in .
A some what interesting ride ( push ) home .
So toss it
Good news is cast iron scrap prices are going up .

Thanks for the heads up. It’s a good price but postage is a crazy price to the uk.

There's one on eBay UK see This Link, +40 so might need boring to +60.

When I was looking for a barrel years ago, Yeomans Motorcycles were recommended to me as the supplier of last resort, see This Link, they didn't have an A65 barrel at the time but suggested to keet calling back as they have a ever changing turnover of used spares.

This shows the weakness of cast iron.
Cast iron is immensely strong in compression but very weak in tension or bending. The load on a cylinder barrel with bolted flanges either end is all tension. Aluminium would be a far superior material in this situation, through bolting would remove the tension from the cast iron and concentrate it in the bolts

Aluminium has advantages and disadvantages.

Many a sporting owner fitted aluminium barrels to a British twin and had subsequent problems.

It has 5/16 studs so will need drilling out and the front pair filing into small slots.
Makes it a bit fiddly to get the nuts on as there are no cutaways but no real problem.
The counter bores on the dowel studs need care when doing.

This is usually because they dd not listen to or seek engineering advice .
You just can not substitute one metal for another & expect it to work well.
The classic case was the titanium fromaed B44 's

I noticed that but the numbers are right for the later barrel as are the cutouts in the bottom fin. I’m guessing his callipers are not reading properly.

Don't risk it mate.

Use it and your other scrap engine bits to make a man cave feature.

Cheers,

Kev Ev

That was my thoughts too Kev, now on the look out for another decent barrel.

Looks like a dual barrel ashtray to me.

Loop a rope or chain through it and use it as a boat anchor.