Nater_Potater
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swooshdave said:There's a solution... you're just not going to like it. :mrgreen:
Here we go again...
About time for the spintron
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Here we go again...
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needless distractions but made me search desmo spintron to find something we might adapt from this demso run, a clear rocker cover and other sealed windows for real time oily parts viewing.
https://www.youtube.com/watch?v=2IstsYgyTAU
https://www.youtube.com/watch?v=2IstsYgyTAU
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Brittywtis, I'm thinking at some point to slice some mass out of various covers for lexan windows in 1' and TS covers but not sure I could do the dome rocker covers and your LED idea has left me restless to pull off too. I'd also like to mount video to observe at speed. Clean rocker covers and others may be our change to make use of 3D printing technology.
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Jim,
Have you tried the Kibblewhite springs yet?
Results?
Regards,
Thomas
CNN
Have you tried the Kibblewhite springs yet?
Results?
Regards,
Thomas
CNN
Fast Eddie
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And, did you and Jim S agree to test some of his kit in the end? That would be really interesting.
Also Jim, at the levels of valve bounce that you are seeing, what would the detectable symptoms, if any, be when riding?
Also Jim, at the levels of valve bounce that you are seeing, what would the detectable symptoms, if any, be when riding?
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CanukNortonNut said:
I have tested them with the PW3 cam. This is my impression so far -not set in stone, more testing to do.
A lot of bounce -pretty much like all the springs tested with the pW3.
They lost control at a lower rpm than either of the other dual springs I have tested so far. [R&D, Sir Eddie's] But more than capable of working in the rpm range of a longstroke motor.
For a mild cam -either the beehive or the conical outperformed them with less seat pressure. Jim
Fast Eddie
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comnoz said:
That may not be perceptable though Jim, wouldn't you agree? How bad would things have to get before there was an audible noise, miss firing, eight striking, etc?
What I'm really getting at here, is that your tests have got me thinking that FAR more of us may have valve bounce than we realise...
Fast Eddie
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comnoz said:
Would it be wrong / inappropriate / ungentlemanly to ask to test the JS springs along with a JS cam and associated lightweight lifters...?
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Fast Eddie said:
There is no question about that.
I guess the only time I have seen a spring loose control enough to cause popping or backfiring or obvious symptoms was when the spring was broken.
You will just think that is all it has, but if you cure the bounce you may be surprised. Jim
Fast Eddie
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The engine will loose potential power. Jim[/quote]
That may not be perceptable though Jim, wouldn't you agree? How bad would things have to get before there was an audible noise, miss firing, eight striking, etc?
What I'm really getting at here, is that your tests have got me thinking that FAR more of us may have valve bounce than we realise...[/quote]
There is no question about that.
I guess the only time I have seen a spring loose control enough to cause popping or backfiring or obvious symptoms was when the spring was broken.
You will just think that is all it has, but if you cure the bounce you may be surprised. Jim[/quote]
Interesting Jim... very interesting !!
That may not be perceptable though Jim, wouldn't you agree? How bad would things have to get before there was an audible noise, miss firing, eight striking, etc?
What I'm really getting at here, is that your tests have got me thinking that FAR more of us may have valve bounce than we realise...[/quote]
There is no question about that.
I guess the only time I have seen a spring loose control enough to cause popping or backfiring or obvious symptoms was when the spring was broken.
You will just think that is all it has, but if you cure the bounce you may be surprised. Jim[/quote]
Interesting Jim... very interesting !!
Hey Jim,
You have the attention of some pretty high powered mathematicians/modelers. Have you asked them to come up with a valve spring system that does not bounce ?
Full Disclosure - I have a BS in Hand Waving and Blue Sky from the UofM, 1979. Proceed at your own risk. Imagine a system of three valve springs that oscillate 120 degrees out of phase (or at three (very) different frequencies). The output waveform could be much smoother than a single spring - think 3 phase power vs single phase. Or a system with two springs that oscillate at close, but not identical frequencies and produce hetrodyne beats at too low a frequency to cause valve bounce before it opens again. Two guitar notes at slightly different frequencies...
The math guys might be able to eliminate a bunch of deadends and come up with something that could actually work.
Just a thought
Greg
You have the attention of some pretty high powered mathematicians/modelers. Have you asked them to come up with a valve spring system that does not bounce ?
Full Disclosure - I have a BS in Hand Waving and Blue Sky from the UofM, 1979. Proceed at your own risk. Imagine a system of three valve springs that oscillate 120 degrees out of phase (or at three (very) different frequencies). The output waveform could be much smoother than a single spring - think 3 phase power vs single phase. Or a system with two springs that oscillate at close, but not identical frequencies and produce hetrodyne beats at too low a frequency to cause valve bounce before it opens again. Two guitar notes at slightly different frequencies...
The math guys might be able to eliminate a bunch of deadends and come up with something that could actually work.
Just a thought
Greg
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Putting current comnoz spintrons together with factoids of detonation means - once in hi throttle red zone all Norton are tolerating both mild detonation and valve bounce, as do most other similar engines with decent power to size 8 weight yet hold together pretty good - right up till they don't. At some point spintrons are run at race wining semi tolerable rpms to see how long to go before replacing something - similar to tires.
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Since I'm already picking up fans at an absurd rate let's keep it going... would hydraulic lifters absorb some of the bounce.
:mrgreen:
:mrgreen:
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swooshdave said:
No, not unless the hydraulic lifters came with a cam with better ramps.
There is a possibility that a 5 inch radius cut on the lifter might soften the landing and do some good. I know it works with some cams but I haven't tried it with a PW3 -yet Jim
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comnoz said:
When I was racing I used a 6" radius on stock exhaust lifters with big valves and hot cam that crowded the valves into the clash zone. It would reduce the duration and give me more valve clash clearance. I just did it on the exhaust side so I didn't lose duration (and cylinder filling) on the intake side. But less duration with the same cam lift means you have more acceleration that wants to throw the lifter off the cam.
xbacksideslider
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WOW, just wow, my head is spinning, great stuff. Thanks Jim and thanks too to for all the other informed commentary.
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