Thumper Club Forum

Technical => Project Progress => Topic started by: timbo on May 30, 2016, 10:35:08 PM

Title: Cylinder fin bodge job
Post by: timbo on May 30, 2016, 10:35:08 PM

Okay, okay, i know its not a single, but as this is the only forum im on, youll have to put up with it. finishing off a 1953 Matchless G9 twin, that me and my mate Tony, bought between us with our pocket money  :-\
Anyway, all going well until we discover one of the cylinder barrels is too bad to hone out, and also has a serious crack. So having searched high and low, with many false leads, and endless later barrels, which dont fit, and offers of others which turn out to be 600 or 650, a kind man in Scotland, takes pity on us, and gives us a barrel. its rough, but standard, and as we need +20, a rebore for £20 sorts that out. Unfortunately, it also has a missing bottom fin. various experts give us their advice, which mostly veers away from getting a fin welded on from the scrap barrel, as it might distort the bore. So, what you see, is my attempt at a cold repair. im actually well pleased at how it turned out, as i am no engineer, and it wont be seen once the barrel is refitted  :)

[attachment deleted by admin]

Title: Re: Cylinder fin bodge job
Post by: timbo on May 30, 2016, 10:36:23 PM

And as for the scrap doner  :-\

[attachment deleted by admin]

Title: Re: Cylinder fin bodge job
Post by: themoudie on May 30, 2016, 11:04:27 PM

Aye Tim,

I like the 'Smiley's' and how many discs to the fin may I ask?  ;)

Pleased someone took pity on you and if the job enables you to get the beastie on the road, so much the better.

My regards, Bill

Title: Re: Cylinder fin bodge job
Post by: timbo on May 30, 2016, 11:44:40 PM

The modern thin discs just flew through the cast iron, like a knife through butter  :)

Title: Re: Cylinder fin bodge job
Post by: JOOLZ on May 31, 2016, 09:07:00 AM

Good repair, well done

Title: Re: Cylinder fin bodge job
Post by: iansoady on May 31, 2016, 09:15:08 AM

Looks good, but an expert welder can do a really nice job. I had several broken fins on the BSA A10 I restored a few years ago and like you sourced a scrap head to get the fin sections from.

Title: Re: Cylinder fin bodge job
Post by: timbo on May 31, 2016, 11:09:40 PM

Yes, but on the law of averages, I decided not to take the risk, as I really didn't want to have to try and track down another one, if it all went pear shaped. Just on the subject, one guy mentioned laser welding? Never heard of this before. Sounds very high tech. Anyway, as you can see from the repair, I am very low tech, and a tight bstd  ;)