Sleeving Atlas & 650 cylinders.

Rohan

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We notice on the NOC that Anthony Curzon recommends someone to sleeve Atlas or 650 cylinders,
and make it a good job. Probably THE man on knowledge of these engines.

After some comments here about sleeving cylinders, thought this might keep some balance and perspective on this subject...
 
Rohan said:
We notice on the NOC that Anthony Curzon recommends someone to sleeve Atlas or 650 cylinders,
and make it a good job. Probably THE man on knowledge of these engines.

After some comments here about sleeving cylinders, thought this might keep some balance and perspective on this subject...
Click to expand...
Please, what means "to sleeve cylinders"?. Rebore?
Thank you.
Piero
 
we have had THIS chat before. a 750 cylinder is a hit or miss at .060 over size. there are core shift issue's that can induce weak spots in some at .060. I have seen the bottom spigot crack on .060 and in my younger and dumber days tried to use a 750 cyl bored to accept junkstall 810 pistons. the later did not work out as it kept trying to seize with and i kept adding more clearance till it finally broke the cylinder at the base flange. if YOU think sleeving a 750 cyl is a good idea than be my guest and report back but my money is on a LOT of broken parts when the cyl leaves the crank cases.

Rohan said:
We notice on the NOC that Anthony Curzon recommends someone to sleeve Atlas or 650 cylinders,
and make it a good job. Probably THE man on knowledge of these engines.

After some comments here about sleeving cylinders, thought this might keep some balance and perspective on this subject...
Click to expand...
 
Sleeving can work ,but there is a significant risk of breaking through to the outside and weakening what is already known to be a bit overstressed. I planted some seeds last year and there are moves afoot to make some new 88 and 99/650 barrells . If you are not in a rush---------.
 
Way back when I had an Atlas I rode the bike down a long outside stair case and on the way home the bike became slower and slower until it locked up. A subsequent engine strip revealed that one of the barrel spigots had broken off and the liner dropped down onto the crank-so I had a new liner fitted from Norton (they were available at the time) I had no more trouble with the liner. I just made sure I didn’t do any more off road riding
 
Thanks Bernhard, the voice of experience.

bill said:
we have had THIS chat before.
Click to expand...

Yes, but from folks with no experience of sleeves ?!
Folks say the same about old sidevalves being resleeved, but I've an M20 engine that has
done serious miles on a resleeved engine.

Sleeves for dommies, and the older singles too, have been around for donkeys years.
As long as they are sleeved (BEFORE they are overbored to ell) by someone who knows what they are doing,
they are good for another life, the sleeve actually strengthens the area around the base.
And if Tony Curzon uses them, he formerly of Gus Kuhn, then they must be good.
 
Rohan
I have a 72 Commando and time allowing I will be sleeving back to standard, bore I have a set of Feked sleeves to do this.

One of the bottom spigot has been knocked off at some time, but I don't see this being an issue.

I am sending a barrel to a foundry I do a bit of machine for to see what it would cost to have a few cast, I would then machine them on my Machining Centre.

The killer will be the price of the patterns.


Burgs
 
that is NOT the same as a 750 cylinder

Rohan said:
Sleeves for dommies, and the older singles too, have been around for donkeys years.
Click to expand...

this has NO effect on the sleeve job as it has in your words to be bored to ell to install the sleeve

Rohan said:
As long as they are sleeved (BEFORE they are overbored to ell) by someone who knows what they are doing,
Click to expand...

this has to be the biggest load of bullocks i have seen as the sleeve is just a press fit to an already thin casting. the ONLY way it would come close to even being as strong would be to weld the sleeve at the top and bottom to the casting and good luck on that one.

Rohan said:
the sleeve actually strengthens the area around the base.
Click to expand...

I had a chat with probably the most respected builder on here today on some other stuff also and he STOPPED doing them as the failure rate was to high for him.

so my next question to you is just how much machine work on engines have you personally done. from the last quote my guess is NONE.
 
Why don't you actually name the builder that had so much trouble ?

No I don't do this service - although my dad used to press sleeves into diesel engines.
Some piston rebuild kits come with their own set of sleeves.
They are hardly a light press fit - they have to be pressed/shrunk in so they are solidly locked in there.
The BSA M20 I have that is sleeved you can barely pick it has been sleeved - the joint is only a shadow in the metal.
If you weren't specifically looking for it, you probably would not detect it.

Nortons only recommended reboring to 40 thou, and (back then) only supplied os pistons to that size.
So if sleeved before reboring to 60 or 80 thou oversize (!)...
As said, Anthony Curzon is the expert on these engines, and he would seem to have sleeved
and reclaimed many engines over the decades - or why would Norton Dealers stock or use the sleeves ?

I too have heard that serious reboring makes the bottom flange rather weak - thats why they need to be resleeved BEFORE the walls get that thin...
And we have Bernhard here with a sleeved cylinder example, all good...
 
elefantrider said:
Can you post the link?
Click to expand...

I'm afraid I only noted the contents in passing, didn't save the link.
Not sure how searchable the NOC Forum is...
 
When resleeving cylinders it depends on how it is done, the barrel will require heating up to about 100 degrees and the sleeve left in a deep freezer overnight, they will still require a press but there will be less chance of damage .
 
all the diesel engines i have seen are what is called a WET sleeve so you are comparing chalk and cheese on this one. i also NEVER stated it was a light press and a proper job will barely show a shadow line from the different metal. so you openly state that norton only recommended plus 040. that is a far cry as to how far you have to bore to install a sleeve as a starndard 1/8 wall sleeve will need to be bored .250over or a thinner wall would need .180. as to bernhard he took the chance and has lucked out but it is not the chance I nor the other builder will take anymore.


Rohan said:
No I don't do this service - although my dad used to press sleeves into diesel engines.
Some piston rebuild kits come with their own set of sleeves.
They are hardly a light press fit - they have to be pressed/shrunk in so they are solidly locked in there.
The BSA M20 I have that is sleeved you can barely pick it has been sleeved - the joint is only a shadow in the metal.
If you weren't specifically looking for it, you probably would not detect it.

Nortons only recommended reboring to 40 thou, and (back then) only supplied os pistons to that size.
So if sleeved before reboring to 60 or 80 thou oversize (!)...
As said, Anthony Curzon is the expert on these engines, and he would seem to have sleeved
and reclaimed many engines over the decades - or why would Norton Dealers stock or use the sleeves ?

I too have heard that serious reboring makes the bottom flange rather weak - thats why they need to be resleeved BEFORE the walls get that thin...
And we have Bernhard here with a sleeved cylinder example, all good...
Click to expand...
 
bill said:
all the diesel engines i have seen are what is called a WET sleeve so you are comparing chalk and cheese on this one.
Click to expand...


Dry lined diesels are common too, but you're right- engines that had liners from new have no relevance to trying to save a worn out air cooled barrel.
 
you are correct. i was referring to the large commercial engines. on the wet sleeve engines it is common place to sell liner kits which include a complete renew assembly. even the dry sleeve engines you are starting from a LOT heaver block.
Triton Thrasher said:
Dry lined diesels are common too, but you're right- engines that had liners from new have no relevance to trying to save a worn out air cooled barrel.
Click to expand...
 
I am following this thread with interest.

My experience with liners has been limited to one case of a liquid cooled engine, and as Triton and bill write, they are an entirely different kettle of fish.

As an engineer, I see the problem of liner replacement in air cooled engines being that of heat transfer. One must achieve virtually a molecular bond between the liner and barrel, in order to achieve original heat transfer characteristics. Even fine honing is not good enough, and neither will a shrink fit eliminate the micro gap between components.

I have heard of copper plating the bore as way of getting the molecular bond, but I cannot speak from any experience. I am skeptical that press fitting the liner past copper will do anything except scrape the copper away. Perhaps shrink fitting a dry ice chilled liner into a copper plated bore will "flow" the copper into microscopic pores, and do the trick.

The degree of interference fit must also be controlled. Too tight, and undue stresses will be set up in the barrels, and too little will not extrude the copper.

Surely, successful resleeving is an art.

Slick
 
Liners do work. I've ridden a sleeved AJS 500 single and it worked just fine.

But there has to be enough metal left after the cylinder is bored out for the sleeve. Enough to avoid worse than usual distortion and enough so the barrel doesn't snap off above the bottom flange.
 
texasSlick said:
As an engineer, I see the problem of liner replacement in air cooled engines being that of heat transfer. One must achieve virtually a molecular bond between the liner and barrel, in order to achieve original heat transfer characteristics. Even fine honing is not good enough, and neither will a shrink fit eliminate the micro gap between components.
Slick
Click to expand...

Actually, this is not strictly true.
And, why would water cooling make the sleeve contact requirement any different anyway ?
Apart from that many diesels were aircooled from some makers...

Since sleeving sidevalve engines since WW2 was a VERY common practice - eeking out more miles on a shoestring budget - it is suggested in the motorcycle press that as the engine gets hotter, the sleeve can ONLY expand outwards - so the already tight fit of the sleeve gets better, heat conductivity wise.
Heat will always flow from hotter to colder, so even if the contact was only minimal, all those minimal points will flow heat - or the bloomin thing would melt !
It takes considerable muscle to press the sleeves in too, so the contact won't be too minimal !

As I said, I have an ex-WD M20 engine that has been sleeved, and done extensive miles since then.
And Mr Curzon sez he's had a number of Nortons sleeved, successfully.

Now, it is also mentioned that the early 650 and Atlas engines had rather minimal metal in the cylinder walls.
Isn't there a memo noting that the wall thickness was increased, quite early in the oroduction of these ?
 
Rohan wrote and my comments:

".... why would water cooling make the sleeve contact requirement any different anyway ?"

Because the cooling medium ( water) contacts the liner directly. It becomes irrelevant if the contact of sleeve and block is imperfect.

" it is suggested in the motorcycle press that as the engine gets hotter, the sleeve can ONLY expand outwards - so the already tight fit of the sleeve gets better, heat conductivity wise. The fit gets tighter, but the heat conductivity likely does not improve much.
Heat will always flow from hotter to colder, true so even if the contact was only minimal, all those minimal points will flow heat at a significantly reduced rate as compared to a perfect molecular bond- 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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