A tale of two heads and one barrel. To spigot or not to spigot?

gpzkat said:
Counterbore is 79.5 or so for spigoted. The counterbore for the non spigot is the same depth but of course smaller. So the pistons will not be impeded in vertical stroke. BTW I have the original lower compression convex pistons, but can't re-use due to the need to bore the barrel. I doubt there's much demand for them but would make an easier kick start I imagine.
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Those pistons may find a new home if you advertise them.
 
Bernhard said:
Re; spigot barrel. Don't shave spigot off- the reason the spigot prevents the liners dropping down onto the crank , don't ask me how I know!!!
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Yikes, thanks for the tip but I'm looking at the bottom of the barrel and like the broken one in the pic above, I don't see anything that looks possible to drop out. It looks like a solid chunk of iron. Do you mean 'if' it had liners? Or they all have them from stock and they somehow are joined most securely at the top, and not throughout? Just trying to understand and learn.

Edit: I read another thread on this subject and am confident there is no liner in mine.
 
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Agreed the OE Barrel is a one piece casting the problem I previously mentioned happens when re-sleeved, over bored [060] high compression or from personal experience when supercharged.
 
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Unless I'm very much mistaken, all the Dominator 500, 600 650, 750 twins including Commando have spun cast liners, you can see it when you look at the bottom end.
 
Bernhard said:
Re; spigot barrel. Don't shave spigot off- the reason the spigot prevents the liners dropping down onto the crank , don't ask me how I know!!!
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Thanks to all. I'm going to make some calls for boring services. I'm creating a spreadsheet of all the parts I need, bagging and tagging and cleaning everything. I have access to a blast cabinet and a powder coater, both free to me, which is great. I glass bead blasted a bunch of stuff last weekend, and they came out great.

After a light blast with aluminum oxide, the rust in the barrel doesn't look too deep, and is only on one cylinder. A the shop will have the tools and expertise to measure and recommend an overbore size. The only 'major' parts I need are the long 24.9" stanchions, toolbox housing & cover and the taillight assembly. I have a line on the the toolbox stuff from Waldridge, a bit pricey for my current situation but nice that he has them if I should lash out.
 
Bernhard said:
Unless I'm very much mistaken, all the Dominator 500, 600 650, 750 twins including Commando have spun cast liners, you can see it when you look at the bottom end.
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Good to make sure, maybe a photo helps. They are chamfered, unevenly - on the right one the chamfering ends at about 4 o'clock. (edited as I flipped the photo). But I see no seam that would help identify a liner - there is a shadow that looks like one but it's a photo artifact at 7 o'clock on the right bore. I'll take to a pro and they'll know for sure anyway.

A tale of two heads and one barrel. To spigot or not to spigot?
 
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I took the barrel up to Q&E in Anaheim CA, and given I live in la-la land, seeing a shop like this here made me happy. Evidently there's a guy who wasn't working today who really knows Nortons, but the gent I talked to knew quite a bit. I think I'm in good hands.

A tale of two heads and one barrel. To spigot or not to spigot?
 
gpzkat said:
He said it didn't have liners, yeah.
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I hate to say it, but you arr not in "safe hands" as you put it.
The barrel us cast in a pig iron and far to porous to use as a clean bore for your piston, when are you going to wake up to this fact????
Go and read the Norton engine section on thos website. You might learn something.
 
For sale on flea bay and other various sites;
Spigot cylinder liners .
Mmmm, funny that, some people don't belive we have them!
 
Bernhard said:
For sale on flea bay and other various sites;
Spigot cylinder liners .
Mmmm, funny that, some people don't belive we have them!
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Yes, you can buy spigotted liners if you want to reline a barrel. Dommies/early Atlas engines had a spigot cast in, it's NOT a separate liner, never was never will be unless you've gone past +60 and reline your barrel
 
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Bernhard said:
I hate to say it, but you arr not in "safe hands" as you put it.
The barrel us cast in a pig iron and far to porous to use as a clean bore for your piston, when are you going to wake up to this fact????
Go and read the Norton engine section on thos website. You might learn something.
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Really? I don't really need abuse, and would prefer you just ignore my posts, I'll certainly be doing the same on yours.
 
Grunt, that's me told, would you kindly send me your twn barrel and I will return them back to you with both spun cast iron liners pressed out.
That will settle this argument for one and for all!
:-(
 
Bernhard said:
Grunt, that's me told, would you kindly send me your twn barrel and I will return them back to you with both spun cast iron liners pressed out.
That will settle this argument for one and for all!
:-(
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You are VERY much mistaken as norton twins NEVER had liners fron the factory. The 750 barrel was pushed so far to the limit on bore size as some wete known to break if you went to a .060 over bore. NO 750 barrel is worth trying to bore for a liner
 
bill said:
You are VERY much mistaken as norton twins NEVER had liners fron the factory. The 750 barrel was pushed so far to the limit on bore size as some wete known to break if you went to a .060 over bore. NO 750 barrel is worth trying to bore for a liner
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You don't make any sense whatsoever. . . .how come my Atlas liner dropped down onto the crankshaft subsequently locking the engine up?
And how do you explain the barrels rough casting which has got no way of producing in that state the fine finish required for a cylinder bore?
I suggest that you sir,have zero knowledge of metaluaugy, and you would be laughed at at any metalwork producing factory.
P.S. send all your brickbats to the little guy in the sky who listens to all the worlds woes! .
 
Bernhard said:
You don't make any sense whatsoever. . . .how come my Atlas liner dropped down onto the crankshaft subsequently locking the engine up?
And how do you explain the barrels rough casting which has got no way of producing in that state the fine finish required for a cylinder bore?
I suggest that you sir,have zero knowledge of metaluaugy, and you would be laughed at at any metalwork producing factory.
P.S. send all your brickbats to the little guy in the sky who listens to all the worlds woes! .
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So what you are stating is that EVERY cast iron block made in the automotive industry came with liners as there is NO way they could achieve a final finish in a rough casting ? Give me a break as i have worked in the automotive machine shop and you sir need to rethink your stance. I also have tried a larger than .060 over bore on 750 Cylinders and usually the results have not been good. This has also been discussed a while back as to using liners in norton cylinders with the same foolishness. As to your atlas I would say somone did a bodge putting liners in it and THAT sir is where your troubles started. To install a liner properly it will have either a counter bore at the top or a step left at the bottom of the bore and without either one of these it WILL result in just what you encountered
 
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Bernhard said:
You don't make any sense whatsoever. . . .how come my Atlas liner dropped down onto the crankshaft subsequently locking the engine up?
And how do you explain the barrels rough casting which has got no way of producing in that state the fine finish required for a cylinder bore?
I suggest that you sir,have zero knowledge of metaluaugy, and you would be laughed at at any metalwork producing factory.
P.S. send all your brickbats to the little guy in the sky who listens to all the worlds woes! .
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Bernhard, IF your Atlas had a liner, why do you believe it was fitted by the factory?

Do you really mean liner, or do you mean part of the protruding skirt broke away?

Reference your metallurgy rant, the VAST majority of British bikes ever built wore liner-less iron barrels…
 
Bernhard said:
You don't make any sense whatsoever. . . .how come my Atlas liner dropped down onto the crankshaft subsequently locking the engine up?
And how do you explain the barrels rough casting which has got no way of producing in that state the fine finish required for a cylinder bore?
I suggest that you sir,have zero knowledge of metaluaugy, and you would be laughed at at any metalwork producing factory.
P.S. send all your brickbats to the little guy in the sky who listens to all the worlds woes! .
Click to expand...

I did see a liner in a race commando drop once while it was being warmed up on the bench. That was about 35 years ago and it was an old barrel that had had a liner put into it to bring it back to standard bore. It was just a (poor) interference fit with no "top hat" on the liner. I also have one as a doorstop, but neither are as they came from the factory
 
Bernhard said:
I hate to say it, but you arr not in "safe hands" as you put it.
The barrel us cast in a pig iron and far to porous to use as a clean bore for your piston, when are you going to wake up to this fact????
Go and read the Norton engine section on thos website. You might learn something.
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So, to re-cap, gpzkat shows a pic of his barrel that appears to not have any evidence of liners. He tells us he’s pretty sure it does not have liners. He takes his barrel to a professional machine shop, who tell him it has not got liners in. You, who have never seen his barrel, are saying that gpzkat and the machine shop guy are both wrong?!

That‘s awesome Bernhard!

Given they’re made out of the same dreadful cast iron, I assume you’d say 850 barrels had liners as well would you?

Cos mine don’t.
 
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