How to ream a small end bush?

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thornebt
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Location: Somerset, UK

Re: How to ream a small end bush?

Post by thornebt »

56G80S wrote:Stuart is clearly a more than competent engineer and sure his advice is worth having.

Last time I went to a previously reputable engineering shop they ignored my advice about how to do a job I'd done successfully before (fitting valve guides in the G80S) treated it like a car head, flogged them out cold, tried to fit the inlet guide in the exhaust while cold and removed and tried to refit by driving up out of the head.

Cost me a packet to have it put right by T&L Engineering who made up an oversize exhaust guide to make up the slack created.

Make sure whoever does work for you understands vintage kit. These aren't swiss watches though.

Johnny B
It's really bad when you go to a reputable place, pay good money to have the job done by an expert and they mess it up!

I've been to T&L Engineering before and you can't get any better than them. They're a fair distance from me but I'm tempted to make that journey to have my barrel rebored. I'm sure there must be a good engineering shop much closer to me in Somerset but I just totally trust T&L.

Cheers. Bruce.

Edit: If I go to T&L I'll obviously take the crankshaft assembly with me and get them to fit and ream the small end bush.
Braaap
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Re: How to ream a small end bush?

Post by Braaap »

What Johnny said.

U need the right people to do the job.

The textbook method would be to break the crank apart and use a Sunnen hone to size the bush, while holding dead parallel with th big end.

An assembled crank presents problems re set-up in any machine.

Possibly the shop mentioned have crossed this bridge already and are tooled up to hone assembled cranks.

Worth a phone call.

If it was my bike i would split the crank and take the rod into town.
But if you have to get it all done out... Ouch £££

But still cheaper in the long run, than re-assembling it with a dodgy gudgeon pin bore.
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Pharisee
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Re: How to ream a small end bush?

Post by Pharisee »

Fortunately, I don't live a million miles away from T & L Engineering and they've done work for me on both my AMC machines and one of my Triumphs.
The G3L cylinder barrel I took them was a shocker. It had been stored in a damp garage for 3 decades with a lump of cloth stuffed into the bore. Once they'd stopped laughing, they re-sleeved it and faced the top surfaces. The also rebuilt the crank with a new big end assembly and a new drive side axle. They honed the little end to suit the new piston gudgeon pin. Couldn't fault the work!
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Expat
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Re: How to ream a small end bush?

Post by Expat »

Very nice looking work. :beer:
Keep shiny side up.

These are my principles, if you don’t like them, I have others. (Groucho Marx)
Braaap
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Location: New Zealand

Re: How to ream a small end bush?

Post by Braaap »

Awesome.

I have a tame guy here. I trust him.
He sized an installed big end sleeve for me...
Come assembly time i was short one roller :cry:
A phone call had him look under his bench. There it was.
I was rapt he had a look, and very grateful he owned up.
He will be boring my compy barrel to 86.50mm and sizing both ends of my rod.
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clive
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Re: How to ream a small end bush?

Post by clive »

I am sure the engineers on here are correct about modern standards but the singles certainly will take a lot of tolerance. I have successfully fitted two small end bushes and reamed them with the engine otherwise in place. Used an adjustable reamer with lots of trial fits as I went. Bit of cloth stuffed in the crankcase to catch the swarf. Unless you are going racing I think this will be sufficient.
clive
if it ain't broke don't fix
ajsm18
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Re: How to ream a small end bush?

Post by ajsm18 »

thornebt wrote: I've been to T&L Engineering before and you can't get any better than them. They're a fair distance from me but I'm tempted to make that journey to have my barrel rebored. I'm sure there must be a good engineering shop much closer to me in Somerset but I just totally trust T&L.
Bruce,

Cox & Turner Engineering are in Somerset, well, their machine shop is at Tintinhull. They fitted a new cylinder liner for my Model 18 along with other work and I'd definitely use them again. Having said that, I've heard many good reports of T&L.

Mark
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thornebt
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Location: Somerset, UK

Re: How to ream a small end bush?

Post by thornebt »

Cox & Turner Engineering are in Somerset, well, their machine shop is at Tintinhull. They fitted a new cylinder liner for my Model 18 along with other work and I'd definitely use them again. Having said that, I've heard many good reports of T&L.

Mark[/quote]


Thanks very much Mark. The name rings a bell and they look very promising on their website. They're only 29 miles away as well. I'll get them to do my rebore and ream the bushes. It's not actually my Matchless, it's for a BSA Bantam.

Cheers. Bruce.
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