New use for a Kibblewhite Performance valve spring (2013)
- Thread starter comnoz
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Well done, Comnoz.
Instead of a spring, I think you would get a better response out of a rubber vibration sandwich mount. So you would be getting a spring plus a damper. So you should get a smoother ride over all rpms.
You know the kind of mount that are on the mufflers and head steady but a little beefier. They are really supposed to be used in compression which is what you have here. Look for them at Mcmaster Carr. They are cheap. You want to add washers underneath till you get the force you like.
You know the kind of mount that are on the mufflers and head steady but a little beefier. They are really supposed to be used in compression which is what you have here. Look for them at Mcmaster Carr. They are cheap. You want to add washers underneath till you get the force you like.
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The mod you see is unrelated to the spring support. Jim had added some years ago an under slung front radius link in his usual unique elegant way. Some links or swash plates may transmit vibes but Peel's added isolation as long as all set to neutral slack. At some point rubber could compress to transmit vibes so easy as it seems to all of us I'll bet its tricky to get it robust enough yet still compliant enough. I don't see how a rubber pad or the spring would add dampening nor the need or desire to dampen free engine orbitals as the dampening must react against something and that something is frame with pilot on it. Thats the extra beauty of good rod links - they don't restrict or dampen vertical motions at'all, if radius long enough. The case is still open on whether a cradle link should be close to the iso like Jims or far away like Peels. Then whether are should be robust as the frame and cradle or some more compliant like isolastics mounts. I don't have that great opinion of the top and front links nice as they are so interesting Jim's still vibed to benefit with a helper spring. Its the robust 'rump rod' that gives me Peel's best Smooth Control Zings.
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Hi Timewarp
My guess would be that Norton likely felt that adding such as you suggest would add so much to the cost of the bike to make it much less marketable
they were already losing market share rapidly to the Japanese on price alone not to mention no leaks, electric starters, carbs that idle, frames that did not go into weaves, etc etc
My guess would be that Norton likely felt that adding such as you suggest would add so much to the cost of the bike to make it much less marketable
they were already losing market share rapidly to the Japanese on price alone not to mention no leaks, electric starters, carbs that idle, frames that did not go into weaves, etc etc
Time Warp said:
From an engineering point of view a single balancer shaft doesn't help a lot on a 360deg P-twin as it introduces a shaking moment while canceling out the forces. Not that much to gain there. You'd need a pair of balancers symmetrically to the crankshaft. Plus they only cancel out first order forces, for second order you'd need another pair geared to twice crank speed. And every additional rotating part means additional inertia. To do it properly a complete redesign of the lower end would be the result I'd say.
From an economical point of view the engine was well past its zenith and the Iso system was more of a cure for the symptoms to survive until there was time and money for a modern replacement....err, wait.
Tim
DogT
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I think Jim posted a pic here long time ago of a Norton engine with a balancer off the front of the engine, looked like an extra small cylinder. Or maybe it was ZDF?
OK, how much and where do I get the Kibblewhite spring and exactly where is it placed, the pic is not real clear to me. From a brace between the frame and the engine or the front iso? And what is the dimension of the compressed spring to get the proper pressure? Will the spring rust (that is if your engine doesn't leak)?
Dave
OK, how much and where do I get the Kibblewhite spring and exactly where is it placed, the pic is not real clear to me. From a brace between the frame and the engine or the front iso? And what is the dimension of the compressed spring to get the proper pressure? Will the spring rust (that is if your engine doesn't leak)?
Dave
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I am in Texas now and I am loving the spring. The last 1000 miles have been the smoothest the bike has ever been.
The spring is compressed enough to raise the engine until the iso bolts line up. I don't have a measurement here.
I can supply a single spring if Kibblewhite can't. I now have a broken kit.
That will be after I get home anyway. Unfortunately it may be in a truck. I got some low octane fuel in Northen Texas and didn't notice the pinging until too late. I now have one damaged piston slowly destroying itself. Jim
The spring is compressed enough to raise the engine until the iso bolts line up. I don't have a measurement here.
I can supply a single spring if Kibblewhite can't. I now have a broken kit.
That will be after I get home anyway. Unfortunately it may be in a truck. I got some low octane fuel in Northen Texas and didn't notice the pinging until too late. I now have one damaged piston slowly destroying itself. Jim
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rvich
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comnoz said:I am in Texas now and I am loving the spring. The last 1000 miles have been the smoothest the bike has ever been.
The spring is compressed enough to raise the engine until the iso bolts line up. I don't have a measurement here.
I can supply a single spring if Kibblewhite can't. I now have a broken kit.
That will be after I get home anyway. Unfortunately it may be in a truck. I got some low octane fuel in Northen Texas and didn't notice the pinging until too late. I now have one damaged piston slowly destroying itself. Jim
Sorry to hear about the piston, but interested in the spring report. I wonder if this isn't a good use for all the used valve springs that get replaced as part of a rebuild. Is there any reason that it would need to be a new Kibble-white? I have been looking at my oil tank and wondering about spring mounting it as well!
Russ
slimslowslider
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Feel sorry for you, that is bad luck, so soon in your trip. Hope you can expedite and install new pistons in after all and continue your trip. Bennie.
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Glad and sorry to know the God's suffer similar fates as rest of us. There's no need of a hi end race level spring, any that fit should do that can adjust mount to center iso bolt, if ya don't have K/W extra's laying around like Jim. Educational both Jim's EFI and friends Combat carb both lost it on the foul gas. I've a bit of 'shine Jim to rise and cool your head's octane at LOP for next leg of adventure into the unknown. Now you've got all us pensive holding breath you don't blow up in middle of nowhere. Looks like the weather is staying pleasant.
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rvich said:comnoz said:I am in Texas now and I am loving the spring. The last 1000 miles have been the smoothest the bike has ever been.
The spring is compressed enough to raise the engine until the iso bolts line up. I don't have a measurement here.
I can supply a single spring if Kibblewhite can't. I now have a broken kit.
That will be after I get home anyway. Unfortunately it may be in a truck. I got some low octane fuel in Northen Texas and didn't notice the pinging until too late. I now have one damaged piston slowly destroying itself. Jim
Sorry to hear about the piston, but interested in the spring report. I wonder if this isn't a good use for all the used valve springs that get replaced as part of a rebuild. Is there any reason that it would need to be a new Kibble-white? I have been looking at my oil tank and wondering about spring mounting it as well!
Russ
When I installed the spring I tried a few different springs I had laying around. The KB spring was the one that seemed to compress about the right amount when I raised the motor with a jack below the spring. When I tried a stock Norton spring it was nearly at coil bind by the time it raised the motor enough to align the iso bolt. The KB spring is quite a bit stronger. I don't have enough experience with it yet to say which spring would actually be the best.
1100 miles now since the piston seizure. The motor taps loudly at idle but quiets down at speed. I still plan on making it to Barbers on Thursday. I'm keeping my fingers crossed. Jim
Hortons Norton
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Have my fingers crossed for ya Jim.
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