Straightening an Amal

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swooshdave

swooshdave

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While this is a Monobloc there no reason the same technique couldn't be a applied to a Concentric.

I think I've done something similar with a vice.
 
Cool. I've heard about straightening them that way, but never saw any details. Thanks for posting.

Ken
 
John Healey has a write up about this along with a design for a jig (which I shamelessly copied), the key is to realign the slide bore with the flange. A bit of heat helps.

Straightening an Amal
Straightening an Amal
 
Good info there. If you grind any bent flanges flat, rather than straighten them it ends up to be trouble... I flattened a carb bowl without straightening it once, It kept leaking, so I kept flattening until the flanges were to thin to do much of anything... lesson learned...
 
I've got a pack of zig-zags out in the shop somewhere...but that's not what I used to use them for.
 
Lineslinger said:
I've got a pack of zig-zags out in the shop somewhere...but that's not what I used to use them for.
Click to expand...

I'm still working my way down the menu of now legal edibles :)

Started with the licorice, then onto gummies, now I've got a bar of "special" butter that I plan to bake some brownies with... fun times
 
acadian said:
I'm still working my way down the menu of now legal edibles :)

Started with the licorice, then onto gummies, now I've got a bar of "special" butter that I plan to bake some brownies with... fun times
Click to expand...

I have NEVER made my own butter.
 
Gummies are the new alternative...no inhaling smoke...got to make the special effort to hide them from the grandkids
swooshdave said:
Yeah, but I bet you don't care about carburetors after you're done with the zig zags.
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Oh I over think and tweak till the witching hours. Then I rearrange my shop and cant find a damn thing thing the next day.
 
The method is great if the flange warpage is as bad as shown but in my experience it usually is not and truing the mating surfaces on a sheet of 1/4" glass/wet-dry sandpaper does the job very well. It would take a serious amount of over-tightening to warp a flange to that extent UNLESS, of course, it came from Amal that way. But that would never happen, right? :rolleyes:
 
MexicoMike said:
The method is great if the flange warpage is as bad as shown but in my experience it usually is not and truing the mating surfaces on a sheet of 1/4" glass/wet-dry sandpaper does the job very well. It would take a serious amount of over-tightening to warp a flange to that extent UNLESS, of course, it came from Amal that way. But that would never happen, right? :rolleyes:
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I suspect the Monoblocs might be more susceptible to overtightening?
 
That could very well be - I have NO experience at all with any Amal other than the original Concentric Mk1 and the Premier version.
 
Years ago a friend bent the flanges of a new pair of Concentric Mk1s. I reckoned the problem was either the "O" ring groove depth was machined too shallow or the "O" ring material cross section was too large. Luckily the slide bores showed no signs of warping so we ground the flange faces flat and fitted thinner "O"rings. Since then I check there isn't too much "O" ring protruding to easily crush.
Dave
 
For O-ring assemblies like the Concentric, I only tighten the nuts to compress the O-ring to where the flange just meets the manifold. Interestingly, even though that "torque setting" is not even what I'd call "snug," I have never have those nuts loosen despite not using loctite. I have had other Norton fittings self-unscrew that were tight and red-loctited.! Go figure!!!
 
Motor cars with side draught carburettors (Weber 40's et al) usually use Thackery washers.....
 
Norton's distant cousin, the Enfield Interceptor Series 2, is a big user of internally toothed locking washers. Everywhere, including the nuts that hold the carbs on. I don't like them as the score everything but they do seem to work and they
allow one to nip up the carbs with very little torque and they don't get loose.
 
There are softer alloy versions of the internally serrated washers available that do not score as prominently, but I'm not sure how effective they are
 
I made a John Healey copy also and usually take it to our yearly brit bike clinic. I have probably straightened about twelve carbs including my own. It works very well. I also use the "fat" oring and a small open end wrench that has been cut off to minimize the torque I can put on the nut. I tighten the nuts equally until there is about .05/ .06 inches between the flange and carb
 
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