Atlas Barrel - rebore to +0.060, hone or ditch?

Hello guys
May I ask for your advice concerning the barrel for my Atlas project bike? The engine was seized when I got the bike and I managed to remove the piston that was stuck. The barrel is in good condition but one of the bores is pretty rusty and I was thinking of getting it bored to the next size. But when I checked the pistons, they are already +0.040 over standard.
My question is, should I even attempt to go for a re-bore of +0.060 over standard or after looking at the cylinders do you think that it might only need a hone?
Thanks for your help

Here are a few pics of the barrel and I have more if needed:

from the pictures i doubt it would clean up at 060 with it at 040 now. you have to remember you are only removing 010 of materiel from the cylinder wall and THAT one is RUSTY.

There's no way a hone will clean that up and still leave it in spec for +.040 Pistons IMHO.

Gotta be worth seeing if they clean up at +.060 I'd say. It seems Pistons are available in +.080 sizes even.

I imagine such sizes are going to weakness the barrels somewhat, but unless you're racing it I would have thought it would be fine?

+1 with above replies.

I would look into nickel plate metal build up and honing back to + 040.

Check out <http://mxratracing.com/cylinder.html>

An advantage of nickel is a long wearing cylinder, similar to Nicasil. Nicasil maybe a harder, longer wearing surface treatment than nickel, but it does not build up lost metal.

Slick

Checking whether it can successfully be sleeved might be a better option.

Folks here seem negative about this, but quite a few sleeves get sold for this purpose.
See if any of the bikeshops in your region can recommend someone.
Or ask say Mick Hemmings etc.
If done BEFORE the cylinder walls get too thin, this is a common automotive practice.

Rohan said:

Checking whether it can successfully be sleeved might be a better option.

If done BEFORE the cylinder walls get too thin, this is a common automotive practice.

Click to expand...

Maybe I'm having a 'brain fog' day or something, but I don't follow your logic.

If you bore the barrels out big enough to take a liner, then the casting will be much weaker than even the biggest overbore...

I have this chat with rohan before but if you argue with a fool it becomes hard to tell who is the fool. his comparing it to the automotive side has NO relevance to a norton cylinder.

Fast Eddie said:

Rohan said:

Checking whether it can successfully be sleeved might be a better option.

If done BEFORE the cylinder walls get too thin, this is a common automotive practice.

Click to expand...

Maybe I'm having a 'brain fog' day or something, but I don't follow your logic.

If you bore the barrels out big enough to take a liner, then the casting will be much weaker than even the biggest overbore...

Click to expand...

Bore looks too far gone with all that rust, the normal method would be to have the rusted sleeve pressed out and another pressed into the barrel –I have had this done in the past HTH

Sleeving Norton cylinders is somewhat common, so your ignorance seems to be showing here ?

Fast Eddie said:

Maybe I'm having a 'brain fog' day or something, but I don't follow your logic.

If you bore the barrels out big enough to take a liner, then the casting will be much weaker than even the biggest overbore...

Click to expand...

The sleeves aren't very thick, so you'd only bore it out enough to clean up the bore, and then fit the sleeve.
And if done BEFORE the cylinder is way past having any strength, this is a common repair method.
ie don't get it out to 0.080" over, and then expect to sleeve it.

I've got a sleeve for a 16H Norton, WD WW2 issue, and its quite thin.
I believe the correct spec is 'spun cast' .
These were used by the thousands it seems, and sidevalve donks are pretty hard on their bores.
So it was certainly good for them.
And sleeves have been available for dommies since, well, since dommies were available...
Hepolite supplied them, amongst others ?

Search for previous threads here on folks using these.
Plenty of good reports around.
LA Sleeve in the US have also been doing these for yonks, they do nothing else.

speaking of ignorance, you have just shown yours. a .0625 wall sleeve will need a .125 over bore and that is as thin as la sleeve list's. PS it is NOT for a norton. from what you posted it would be an .030 wall sleeve, good luck on that one.

Rohan said:

The sleeves aren't very thick, so you'd only bore it out enough to clean up the bore, and then fit the sleeve.
And if done BEFORE the cylinder is way past having any strength, this is a common repair method.
ie don't get it out to 0.080" over, and then expect to sleeve it.

I.

Click to expand...

There is something you are missing though - although the sleeves are thick - although not usually that thick ? - they are fitted and then the INTERNAL size is bored/honed out to suit.
So the resultant sleeve is not all that thick ...

The one in my old M20 engine is quite thin in fact.
And would seem to have done plenty of miles....

So have you tried any sleeves in any of your engines ??
Actual experiences....

500cc dommie sleeve - with spigot.
Not much thickness to it.....

http://images.classicbikepartscheshire. ... 095000.jpg

And this post on the NOC Forum.
Some familiar names there with good reports.
http://www.nortonownersclub.org/noc-cha ... /110372709

And a couple of pics on this very forum, for an Atlas that has been sleeved back to std





Wonder how they are holding up ?

I understand that boring out the existing barrels with something like +80 weakens the existing lower cylinder not the cylinder casting as such, this can lead to a higher risk of the bottom part of the cylinder that protrudes into the crank case cracking off. Some people seem to have had bad experiences with liners others swear by them, many Norton parts suppliers certainly seem to offer them for sale, so I imagine that some people must have had good results with them. I myself have never had to fit liners in a cylinder but I am interested in hearing from anyone who has done so with good or bad results.

When this was discussed previously here Dave, a whole string of folks came out of the woodwork with stories of their Norton being sleeved - sometimes only in one cylinder - after some tale of mechanical mayhem.
And seemingly still on the road.

Those 2 gents above in the NOC link are both club stalwarts, so if its good enough for them to have engines sleeved. They even recommend who to use for a good one...

And, it is very likely that a number of Nortoneers here could have engines which have been sleeved, and the current owners are not even aware of it, it used to be very widely done.
For many years Nortons only offered up to +0.40 oversize pistons, so once you reached there it got expensive (new cylinders). So Hepolite et all supplied sleeves to cover this. The sleeves I've seen have been less than 1 mm thick, so needing 80 thou is being generous ? That said, I've seen pics of cylinders with sleeves visible through the fins !!!, so not all sleeves may be the same initial diam... Its only relatively recently that +0.060 and even +0.080 pistons have become available - which is where flanges parting company woes really begin (?)

On that theme of not knowing that cylinders have been sleeved, this is a pic of a spare Enfield cylinder.
If you look closely, that fine line around the lip of the flange is yep - a sleeve.
Less than a mm thick, once installed - about 60 thou total.
Ignore the coat of anti-rust ( stops spares rusting away ).
I don't know the history of this - came with some junk - but the somewhat rusty bore says this was on an assembled engine - that later got water in it ..

dave it is not just the lower spigot that is prone to breaking off. the 750 cylinder is also week above the base flange with some worse than others.

dave M said:

I understand that boring out the existing barrels with something like +80 weakens the existing lower cylinder not the cylinder casting as such, this can lead to a higher risk of the bottom part of the cylinder that protrudes into the crank case cracking off.

Click to expand...

when you look at this pic you can see the core shift by the amount of material left at the inside edges. like i stated the cylinder is weak ABOVE the base flange and are known to break there also with a large over bore. you keep going back to a 16H with a sleeve and again it is chalk and cheese. yes you could use a thick wall sleeve with an OD of .060 from std than bore to std but it will be only a .030 wall of the sleeve left. that is NOT a chance i would like to take. if some one wants to risk a lot of expensive engine parts on a sleeve job than go ahead BUT i sure would do it or recommend it. i have sean what happens when a cylinder breaks at the base and you better dig DEEP to fix it.

Rohan said:

And a couple of pics on this very forum, for an Atlas that has been sleeved back to std

Click to expand...

bill said:

yes you could use a thick wall sleeve with an OD of .060 from std than bore to std but it will be only a .030 wall of the sleeve left. that is NOT a chance i would like to take.

Click to expand...

Thin walled sleeves are very common in the automotive world - well proven technology.
Yes, even in 16H Nortons and myriads of dommies !!

So why then are Anthony Curzon and Peter White of the NOC mentioning they have had more than a few engines (750 Norton engines) done with this ? And even recommending folks to do it.

Just because you have doubts doesn't mean it can't be done, successfully, by skilled operators.
LA Sleeve have sold gazillions of sleeves for all types of engines.
Search here and see how many folks mention them...

I agree with Rohan, I've had a few cylinders sleeved with great success, and the sleeves don't have to be of huge wall thickness.
However back to the OP. That set of barrels looks pretty much like scrap to me as they are, because of the one rusty bore. So why not sleeve them, before the bores get too big to be sleeved, rather than trying to overbore and see if they clean up. If they don't clean up the bores are likely to be oversize for sleeving, then the barrels really are junk.
cheers
wakeup

I cannot believe a 0.030" thick liner would work in this application, especially with the con rod cut outs already creating an 'area of concern'.
But I've never tried it, has anyone else?