increasing tappet clearance

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
Yak
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Location: SOUTH AUSTRALIA AUSTRALIA

Re: increasing tappet clearance

Post by Yak »

Hi Chris
Bit of bad luck.
Try these


MODAK 0396 021229

Norm Jenerette 0249 845656
Both of NSW
Good luck
Ray
Chris Berry
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Re: increasing tappet clearance

Post by Chris Berry »

Here is a photo of the barrel. I'm not sure if this was weakened by re sleeving or not but it's pretty broken. I guess all it's good for now is as a donor for other barrels/heads with broken fins
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Last edited by Chris Berry on Mon Jun 12, 2017 1:41 am, edited 1 time in total.
Mick D
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Location: Aberdeenshire

Re: increasing tappet clearance

Post by Mick D »

Hi Chris

That's well and truly bust, but you knew that anyhow. Whoever re-sleeved it seems to have taken off far too much material and reduced it to scrap for you, (unless the photo is deceptive). Differential expansion between the cast iron and sleeve is probably responsible for the failure, or possibly vibration.

Just a general question to those who know - were the barrels sleeved from new?

Regards Mick
SPRIDDLER
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Re: increasing tappet clearance

Post by SPRIDDLER »

Mick D wrote: Whoever re-sleeved it seems to have taken off far too much material and reduced it to scrap for you, (unless the photo is deceptive).
Agreed. Sadly it's scrap. It's possible that the liner O.D. was too great and that too much cylinder was removed to fit the oversized liner. Consequently the wall thickness of the barrel is now too thin thin (judging by the broken off bit with the two bolt holes).
Just a general question to those who know - were the barrels sleeved from new?
They were.
I think I've seen some very early 20th century cylinders (not necessarily AMC) that were unlined.
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56G80S
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Re: increasing tappet clearance

Post by 56G80S »

Hi

You could do as I eventually did and simply take an angle grinder to the fins and make a different era barrel fit (I didn't have room to adjust a front mounted SR1 as it was fouling the barrel). I would warn you that the fins on mine were a devil to cut.

Johnny B
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clive
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Re: increasing tappet clearance

Post by clive »

56G80S wrote:Hi

You could do as I eventually did and simply take an angle grinder to the fins and make a different era barrel fit (I didn't have room to adjust a front mounted SR1 as it was fouling the barrel). I would warn you that the fins on mine were a devil to cut.

Johnny B
I have also done this mod for both the SR1 Mag and the rear mounted mag. Unlike John I seem to remeber doing it with a heavy duty hacksaw. As you have an original barrel to take the measurements from it (albeit with a big chunk missing) should be fairly easy to mod the standard barrel.
clive
if it ain't broke don't fix
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