britbikemike
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66 Atlas Engine-Stuck
- Thread starter britbikemike
- Start date
britbikemike
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Paul, Are those jugs toast? I know that hole looks bad, but it seems functional. What is your opinion on using it?
Wow - you have got the original dished top pistons, as factory installed on Atlases.
This was the factory solution for a low vibe motor.
Whether they are any good these days is another question, but folks would kill to get hold of a new pair of those.
Course, they may go a little slower, but if you can rev the zinger out of it without your fillings all coming out....
This was the factory solution for a low vibe motor.
Whether they are any good these days is another question, but folks would kill to get hold of a new pair of those.
Course, they may go a little slower, but if you can rev the zinger out of it without your fillings all coming out....
Matt Spencer
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Is that bottom of the sleeve knocked in a little , with a crack going up to the right , or is it just casting flash ?
If its not on the thrust face , may be possible to ignor it . Slot cuttout rod clearance ? Looks pretty clean inside .
Can pay to overhaul to service specs , i.e. replace only essential parts worn past limits . Rather than the better than new ' race spec ' .
The pistons look pretty clean . No scuffing or scouring . Slotted behind oil ring generally 6.000 rpm max .
years back a bloke on a farm tried to sell me new chains and other spares he'd bought for the Atlas he'd bought new .
He'd used it for a few years , and toured Europe for a few years . No Bothers . Said over 90 mph the bars twanged with vibes,
so he generally kept to 80 mph , though he'd done 90 mph for a few hours a number of times without looseing any components .
I think he'd ridden it down to Singapore , and sold it after a few years in N.Z. as there wernt service agents in the boondocks .
Any chance of a few pictures . Barrels Inverted , from front , and rear . to suss the spiggots. ? thanks .
If its not on the thrust face , may be possible to ignor it . Slot cuttout rod clearance ? Looks pretty clean inside .
Can pay to overhaul to service specs , i.e. replace only essential parts worn past limits . Rather than the better than new ' race spec ' .
The pistons look pretty clean . No scuffing or scouring . Slotted behind oil ring generally 6.000 rpm max .
years back a bloke on a farm tried to sell me new chains and other spares he'd bought for the Atlas he'd bought new .
He'd used it for a few years , and toured Europe for a few years . No Bothers . Said over 90 mph the bars twanged with vibes,
so he generally kept to 80 mph , though he'd done 90 mph for a few hours a number of times without looseing any components .
I think he'd ridden it down to Singapore , and sold it after a few years in N.Z. as there wernt service agents in the boondocks .
Any chance of a few pictures . Barrels Inverted , from front , and rear . to suss the spiggots. ? thanks .
britbikemike
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Rohan said:
I guess I should have taken a little bit more care when I beat them out of there then. I chipped up the bottoms of them by accident. WONDERFUL! lol
britbikemike
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Matt Spencer said:
I can take pics of the barrels tonight when I get home. I am starting to get sick from the fact I probably ruined the pistons. I didn't realize that they were sitting on the engine case when I whacked it and chipped up the bottoms of them. Never even thought for an instant that stuck pistons could be used again. I guess each bike teaches us a lesson, and that was a hard one. Those pistons can't be saved I would assume.
I did say that folks would like to find NEW dished top pistons.
I'd doubt that those would be good to go - as someone said, it will likely need a rebore.
And the rings could well be stuck in their grooves ?
Once this happens, the ring grooves are usually not good.
I'd doubt that those would be good to go - as someone said, it will likely need a rebore.
And the rings could well be stuck in their grooves ?
Once this happens, the ring grooves are usually not good.
Why not source a second hand barrell, the Atlas ones seem a bit cheaper than those for Commandos. I'm sure it would be cheaper than trying to salvage this one. I would certainly not be happy to leave those cracked lower sleeves even with a fresh re-sleeve job. As others have said you would probably be re-boring and fitting new pistons anyway.
britbikemike
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You know, here is the funny thing. The barrels and top end are EXACTLY like the ones on my Commando. Are they not supposed to be?
The bolts either side of the sparkplugs are smaller in an Atlas than any other Norton motor.
Not sure how long this continued for.
Makes them easy to pick against 500, 600, 650 and Commando parts.
Maybe this was only for when the cylinders had top spiggotts, and the heads machined for this ?
Not sure how long this continued for.
Makes them easy to pick against 500, 600, 650 and Commando parts.
Maybe this was only for when the cylinders had top spiggotts, and the heads machined for this ?
britbikemike
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Well I took the jugs in for the Commando and the Atlas today. The Atlas had not been bored before, however they were cracked. I am getting an estimate for a guy to fix them. He is also going to bore and hone the Commando jugs at the same time. I'll let you know how it turns out.
