And now for an old timey tech question
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And now for an old timey tech question

This is a discussion on And now for an old timey tech question within the General forums, part of the Caferacer.net Forums category; Anybody ever double up the springs in their points to get more RPM out of them? I've been told from racers running them, that the ...

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  1. #1
    Senior Member Mercury Kid's Avatar
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    And now for an old timey tech question

    Anybody ever double up the springs in their points to get more RPM out of them? I've been told from racers running them, that the valve springs I just put in my 350 Honda are good to at least 11,500 but they also said the points will float around 10,000. I want that extra 1,500 and can't afford an electronic ignition.

    I fully expect them to wear out faster, no biggie. I'm going to try the springs from my current well used points added to a new set and run it, but was wondering if anyone had done it before.
    Those scooter jockeys? Yeah real cycle trash for sure.

  2. #2
    Senior Member kenessex's Avatar
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    I have never floated points. In my experience, stock valve spring retainers cause valve float at 11,500 RPM. Lightweight aluminum retainers float at 12k and then break.

    Ken
    WERA 119
    CCS 119
    CRA 119
    AHRMA not anymore
    \"Think twice before you speak, and then you may be able to say something more insulting than if you spoke right out at once.\"
    Evan Esar
    Newbies, Geeto and Tex (Bye Tex)hate me!!

  3. #3
    Senior Member HackAsaw's Avatar
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    i cannot imagine getting retainers to live beyond 12k should be too tough

    tried shot peening & cryro of xray confirmed good stockers?

    I'd stab them with steel shot to an alemite height of around 15 thou just for chits and grins...

    if that did not work I am sure better metals can be had without having to do ti retainers, valves an CuBr seats

    you are probably being told right on the points.... what most do not know.... so they cannot tell you is

    the same ignition condensors which will result in long point contact life for a street riding... will no balance the LCR circuit for racing speeds...

    so you will need to study a bit to decide if I'm blowing smoke... and then decide if you will require more or less capacitance to minimze metal transfer between the points contacts

    they are measured in micro farads

    mfd's
    Accidental inventor of the worlds fastest wearing rocker arms and other edible engine parts! Try my yummy blue cheese camshafts!

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  5. #4
    Senior Member HackAsaw's Avatar
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    and of course, double the springs and use some known high quality extreme pressure grease on the points cam so the damnits do not wear rapidly and have you adjusting the points halfway through a race
    Accidental inventor of the worlds fastest wearing rocker arms and other edible engine parts! Try my yummy blue cheese camshafts!

  6. #5
    Moderator jbranson's Avatar
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    When I had points on my 175 I always figured if a set of standard points could suffice a V8 revving to 6k, then they'd probably suffice a twin revving to 12k ... if you see what I mean. But then the factory redline on the 175 was 10K anyway.
    It's been my experience that most race bikes running points usually have other problems that limit their performance prior to the points becoming an issue.
    Ti retainers are cheap enough, long lasting, and I've run them to 13k no problem with lightened rockers, Kibblewhite springs, a reasonable cam profile and good oil.
    JohnnyB

  7. #6
    Senior Member Mercury Kid's Avatar
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    I was told not to lighten my rockers. In fact I was told one of the first things to do when you get a hot cam is to weld them up and have them re-profiled to take the added abuse. I have a stock cam, valves, retainers, and Performance Machining valve springs straight out of the back of Cycle Rider from the 70's.

    It's not a race bike, I don't have the money to race, nor the riding skill but I want to do what I can on the street, and maybe if I ever get the itch I can safety wire it and hit the track.
    Those scooter jockeys? Yeah real cycle trash for sure.

  8. #7
    Senior Member Victor52b's Avatar
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    quote:Originally posted by HackAsaw

    I'd stab them with steel shot to an alemite height of around 15 thou just for chits and grins...
    What does that mean? Do you shot peen them into grease fittings?


  9. #8
    Senior Member HackAsaw's Avatar
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    it may mean that and could possibly be evidence of dementia

    i'll google dementia and get back to you on this one

    Accidental inventor of the worlds fastest wearing rocker arms and other edible engine parts! Try my yummy blue cheese camshafts!

  10. #9
    Moderator jbranson's Avatar
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    As far as rocker arms go...depends on the engine and the design of that particular rocker. I can only speak to the rockers on small Hondas 175 and below. I've never personally seen a Honda rocker break, typically they'll eat the cam/lobe side long before they break.
    Here's what a typical lightend stock Honda rocker would look like.
    http://www.jrbranson.com/HondaRacer/...ocker_arms.htm
    I performed similar lightening to all the rockers used in my race engines, could spin them to 13K no problem with about twice the spring pressure of stock springs. Important to lighten them in the right areas, areas of low stress and high Moment Arm.

    Doesn't seem like much, but a reduction of 7 grams in the right areas can shift the float rpm enough to make it worth while.

    Most of the time rocker welding means hardfacing the rocker pad where it contacts the cam, not welding on the structure of the rocker arm itself which would probably just compromise it's strength and warp the rocker shaft bore....which has very small tolerances.

    JohnnyB

  11. #10
    Senior Member kenessex's Avatar
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    HackA,
    I was just relating my personal experience with the listed components in my race engines. In fact, with the engine configuration I was running, 11.5K worked just fine and was very reliable, for a race motor. 12K didn't seem to offer an advantage in performance but did add noise and accelerated wear to the components I was using. I am sure that I could have easily upgraded the springs, valves, retainers and cam to gain more rpm, but at what expense and cost to reliability? I bet I could have found more HP by getting it on a dyno (or dino since this was in 1981), fine tuning the carburation (30mm Lectrons)and removing the alternator rotor ( I like charging systems).

    The package could have been developed further but I didn't feel like it at the time.
    Ken
    WERA 119
    CCS 119
    CRA 119
    AHRMA not anymore
    \"Think twice before you speak, and then you may be able to say something more insulting than if you spoke right out at once.\"
    Evan Esar
    Newbies, Geeto and Tex (Bye Tex)hate me!!

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