Sleeving Atlas & 650 cylinders.

Triton Thrasher said:

In service, heat conduction from the liner to the casting isn't an acute problem.

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Several of the posts above describe seize ups as the failure resulting from a relining job. If so, that is a heat conduction problem.

Other failures noted above stem from taking too much metal away. That is an inexcusable error on the machinists part, unless the cylinder design simply was inadequate in sufficient metal in the first place. I will forgive the machinist if the customer insisted on an over bore liner to gain more displacement.

As I stated above, I have no experience in sleeve jobs .... i am not saying they cannot be successful .... however, I am more expert in heat transfer than the average engineer, and IMO the contact of the liner to casting will be a major determining factor in the success or failure of an air cooled cylinder reline job. I merely wished to point this out so those who contemplate sleeving barrels will favor a shop that uses a process that addresses this point.

Slick

Seize ups would have to be related to the clearance they were bored to ?

The M20 engine I have with good miles on it just seemed to have a normal piston clearance to the bore,
(and sidevalve engines traditionally run pretty hot) so inadequate clearance could well be the culprit you mention.

As said before too, watercooled engines really wouldn't make any difference to good contact to the sleeve.
Plenty of diesel engines use this system - no oversize pistons, just a new sleeve supplied with new std piston.
They are just pressed in dry, with a suitable interference fit, and then honed to suitable clearance.
Very common practice in the diesel world.

it is not a heat issue. it is failure of the casting above the base flange.

texasSlick said:

Rohan wrote and my comments:

[/color]- or the bloomin thing would melt !" From what I read in the posts above, that seems to be the problem!

Slick

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texasSlick said:

Several of the posts above describe seize ups as the failure resulting from a relining job. If so, that is a heat conduction problem.

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You're jumping to a dubious conclusion, perhaps because you "are more expert in heat transfer" and are displaying that knowledge at every opportunity.


A siezure after re-sleeving is highly likely to have the same cause as the very common siezures after ordinary rebores: the stupid machinist has got the piston too bloody tight in the bore! Or- the stupid owner is labouring it up hills at low rpm.

the seizure was NOT from a sleeve job . I had made an attempt to fit a set of 810 pistons in a 750 cylinder. the results was it was to thin.

texasSlick said:

Several of the posts above describe seize ups as the failure resulting from a relining job. If so, that is a heat conduction problem.

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Some engines have substantial metal and the liner makes little change to the sructural strength. Norton twins particularly the 99 and 650 and Atlas have a history of fracturing around the base,especially when tuned/raced. I have seen several linered 99 barrels where the liner can be seen through the fins. Liners have also been known to drop and break off lumps. When there is no option then a liner is an answer, I have some hopes that new 88/99/650 barrells will be availiable in the future from a uk manufacturer, When you think about it the last ones were produced in the early 1960's no wonder they are scarce.

norton bob said:

Norton twins particularly the 99 and 650 and Atlas have a history of fracturing around the base,especially when tuned/raced.

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Again, isn't this related to that the early 650 and Atlas cylinders (and the earlier 99 design) were a bit thin on metal around bores.

At some point not too far into their life, the (650 and Atlas) cylinders were strengthened in this area ?
(The 99 never was, its production life ending circa 1962).

I'm sure this has been discussed here before, possibly by BenG ?

norton bob said:

…I have some hopes that new 88/99/650 barrells will be availiable in the future from a uk manufacturer…

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On 31th. January 17 I was told by Joe Seiffert it will take at least six months till the new barrels will be available at Andover Norton.

Fritz

Difrerent source of supply for cylinders. In the uk most of non Commando Nortons in use and without a supply of cylinders are 7,77, 88,99 ,650. And there are lots of these. 750 cylinders don't seem to be a problem .

norton bob said:

Difrerent source of supply for cylinders. In the uk most of non Commando Nortons in use and without a supply of cylinders are 7,77, 88,99 ,650. And there are lots of these. 750 cylinders don't seem to be a problem .

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There may be a shortage of except for the 750s, but in the early life of the Commando and during the Atlas production run used 750 cylinders were like hen’s teeth :!:

There also may be a shortage of liners, but it is relativity easy to get some liners turned up on a lathe, and they can be left slightly oversize to fit the barrel -no problem.

Its likely that the shortage of Atlas and early commando barrels was down to AMC not being capable of producing them and relying on stock from the closed Norton factory. There was a lot of dumping of substandard stuff till AMC got their act together.

The Commando wasn't even thought of when Nortons moved from Bracebridge St to Plumstead (1963),
so Commando barrels couldn't ever have come from Nortons old stock.

And Nortons only ever made spigoted cylinders, so ONLY AMC could have manufactured non-spigoted cylinders.

We shouldn't generalise too much ?