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Valve Spring Science

  • Grease Monkey
    Grease Monkey
    6 years ago
    Being the inquisitive bugga that I am I was digging around looking for info on the benifits of conical springs over straights and beehives, this video came to light, it's quite long but if you watch it you will learn a thing or two, if anyone wants to discuss what he has to say after watching it I'm in.
    https://youtu.be/uHw3mWYgO6M
  • Ratbob
    Ratbob
    6 years ago
    It’s gotta beat what on Tele. 
    Thanks for the link.
  • beaglebasher
    beaglebasher
    6 years ago
    The link isn't working 
  • Ratbob
    Ratbob
    6 years ago
    Quoting beaglebasher on 17 Sep 2019 09:31 AM

    The link isn't working 

    Yeah, ya gotta highlight/select it and click “look up”. Looks like an interesting series.
  • speedzter
    speedzter
    6 years ago
    That video put me to sleep the first time I watched it a few months ago. Had to speed it up to stay interested . He takes half an hour to say what you could in 10 minutes ! Not exactly " leaked new tech" 
    It's worth looking up a test with a Spintron to see the spring harmonics in effect.
  • Grease Monkey
    Grease Monkey
    6 years ago
    Nothing new under the sun they say, however I found the frequency comparison quite an eye opener, the old straight spring hardly changes but the other two ramp up significantly the further they are compressed and that's a desirable factor for a valve spring.
    Having seen pictures of many beehive valve spring failures I can't help but wonder if they way these springs are traditionally set up in a Harley head is perhaps a contributing factor?
    Every thing I have read or even been told personally about valve spring set ups is questioned in this video.
    This makes we wonder if the beehive springs are not being used to their full potential.
    As he said and the results showed that .025" from coil bind gives the best frequency result for conicals and beehives.
    Thinking perhaps the .060" from coil bind that is commonly trotted out for Harley heads is because that's what you need for the straight springs because of the lack of frequency damping to prevent damage?
  • Grease Monkey
    Grease Monkey
    6 years ago
    When they make something with a spring rate more applicable to our needs they have to be a winner for sure, a lot say the cost is not worth the gain but the actual cost per spring isn't that bad and a better mousetrap is a better mousetrap, there are some available in the ballpark but more for .600" lift, when you go over that there doesn't seem to be much unless over the nose pressure doesn't bother you, food for thought for sure.
  • Grease Monkey
    Grease Monkey
    6 years ago
    Thanks Hoody, questions, geeze I have a few but I will start with a ramble, stock or similar cams produce an amount of work for the stock beehive spring to control, the stock springs are mostly fine in this application because of their fit for purpose design, although at red line perhaps not so much! 
    Go up a notch with cams, think 37's, 48's, 57's or similar that are slightly higher in lift and have a little more duration and perhaps steeper ramps and the same springs can handle the task but do it better if you set them up to suit, at some stage in this cam swap scenario as the cams you want to use get bigger you are going to get to the point where you run out of spring/valve control where the cam exceeds the springs operating range, bind, rate etc. Remember, only talking about springs ok.
    Questions:
    1. Apart from experience is there a way, mathematical or otherwise to determine what rate of spring you need for a given higher lift cam for the spring to maintain control of the valve? Valve weight, seat pressure at 180, ramp angles and over the nose pressure factored in?
    2. Given what David had to say in the video should we be setting beehives closer to coil bind than is (anecdotally) accepted and if not why not? He does say .025" from coil bind gives the best frequency control, lowest I've seen recommended is .055", .060" is the usual figure.
    3. Away from beehives for a sec, while the stock straight springs in CVO 110's like mine are a good quality spring they are what they are in the spring tech hierarchy, why do Harley use them? Is it purely because of the intake valve weight requiring the higher rate they provide? I believe they have a seat pressure of around 150 ish, why that low when 180 is desirable?
    If I'm not making any sense tell me FFS, just trying to learn if I can.
    Cheers.

  • speedzter
    speedzter
    6 years ago
    What I find interesting, is the "one spring fits all"  ideology .
    A set of springs are chosen (mainly on lift requirements ) , the installed height is set-up, and
    then you fit any Cam you like that is within the max safe lift range.
    Obviously there is more to it than that, but you get the point.

    In my SE 110 style heads, I have AV&V .650 beehive springs fitted.
    These heads are running a 2.12" intake valve.
    Another set of ported stock style heads I have are running the same springs.

    Consider the difference in the valve weight between the large 2.12" intake valve and the 1.61" exhaust valve
    in the stock style head, yet they both run the same spring.
    Wouldn't you think they would require different springs to work efficiently ?

  • Grease Monkey
    Grease Monkey
    6 years ago
    When I mentioned stock springs/heads and redline in my head I was thinking stage 1 bike, first thing a lot do is change exhaust and intake along with a tune flashed in that could well have the redline at 6500 and wring it's neck, no power but they will spin up there.
    Reason I asked if there was a method of choosing the right rate of spring for a given cam is that some cams have steeper ramps like say a leineweber and it stands to reason a faster spring would help the lifter stay on the cam over the nose and on the way down rather than be lofted and land on the back on the way down where as a gentler ramped cam could get away with less pressure and be more friendly to longevity.
    I see that there are a few differences in poundage at different installed heights for different springs supplied by different vendors to so I guess it's not all one size fits all, there are options.
    On the CVO duel springs I figure I didn't word my question very well, what I ment is given the beehive spring is considered a technically better design why do Harley continue to use the dual spring instead of an appropriate beehive for the application? Is it because of the rate or are there other considerations?
    Thanks for the input to date gents, appreciate it.
  • Grease Monkey
    Grease Monkey
    6 years ago
    Yep I understand on the loosing force over time, seen that often when rebuilding cat diesels, I understand starting with a known component, your reputation is on the line, I would do the same.
    Will test mine to see what I have and go from there, before seeing that video that I thought I would have to change mine for certain because of the 263E's .637" lift.
    If they are not up to scratch then I will have to sort something out, RAMS has AV&V in doubles and beehives in stock, they are only an overnight bag away, can't find a supplier for the kibbles with caps and locks for my 5/16 stems.
    The figures you put up earlier are stock 05 up beehives yes?


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