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2G Camshaft degreeing help

Posted by DSM_Kola, Sep 15, 2020 at 1:16 PM

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  1. DSM_Kola

    DSM_Kola Probationary Member

    9
    1
    Joined Jun 28, 2019
    Franklin, Wisconsin
    Hello everyone, I have Kelford 272's with some aem adjustable cam gears and I was wondering if others would look over all my measurements, there are a few things that I'm a little unsure about.


    All of my Measurements
    Intake Timing
    When Cam gears are at 0 degrees
    Open 5
    Centerline 107
    Close 45

    When Cam gears are at 2 degrees retarded
    Opens 3
    Centerline 109
    Closes 42

    Exhaust Timing
    When Cam gears are at 2 degrees Retarded
    Opens 45 or 47?
    Centerline 112
    Closes at 1

    Intake Valve clearances
    When Cam gears are at 2 degrees retarded
    20 .386
    15 .325
    10 .281
    5 .247
    0 .226
    5 .215
    10 .220
    15 .235
    20 .271

    When Cam gears are at 0 degrees
    20 .391
    15 .334
    10 .282
    5 .247
    0 .222
    5 .213
    10 .216
    15 .231
    20 .259

    Exhaust Valve clearance
    When Cam gears are at 2 degrees retarded
    20 .312
    15 .290
    10 .275
    5 .272
    0 .282
    5 .303

    So the first thing that I was unsure about was that for the intake time it seemed odd that it was very close at the opening and centerline, but the closing event was 5 degrees off. The next thing was that when I was doing the exhaust timing I found that when I was doing the opening event and I waited some how it would slightly open like it was. For example I would find the opening at 0.040" at 45 degrees and I would wait a few minutes and it would be 0.047" and it would still be at 45 degrees. Should I take the initial measurement or account for the movement? Another thing is it normal to have that much valve clearance and should I just keep the cams set at Kelford specifications?

    Would any of these things be caused by human error, like have I done anything wrong to cause these mishaps, being this is my first time degreeing anything. All advice helps
     

    Attached Files:

    Road Race Build 225  1

    1995 Eagle Talon TSi AWD
    awd · manual · 2G DSM
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  2. kanusky1990

    kanusky1990 Proven Member

    97
    10
    Joined Sep 14, 2011
    Easton, Pennsylvania
    Are you using solid lifters while taking the measurements?
    If you are using the normal hydraulic lifters, they will bleed down over time from the spring pressure and give you an inaccurate measurement. It sounds like that is what is happening when it changed from 0.040" to 0.047" while maintaining 45 degrees.

    Great Jafro video for information:
    He shows how he made solid lifters around 9 mins in
     
  3. DSM_Kola

    DSM_Kola Probationary Member

    9
    1
    Joined Jun 28, 2019
    Franklin, Wisconsin
    Oh yeah I forgot to mention that, yes I am using solid lifters that is why I was so confused when it changed.
     

    Road Race Build 225  1

    1995 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  4. jakelandry

    jakelandry Proven Member

    906
    115
    Joined Oct 13, 2009
    Minden, Louisiana
    I have degreed a handful of cams and had similar scenarios where non-linearity occurs. Because of this, I always just focus on one event. You can’t get an indicator dead inline with the valves, you have some room for error with the solid lifters, the human eye is only so accurate with a homemade stick and wheel combo. It always made the most sense to me to pick one valve event and hit it. Why follow the cam through it’s entire cycle and compare the opening and closing events when there are so many variables to take into account? The opening and closing events are fixed by the cam and you’re not going to change them in relation to one another, so just pick one, set it, and forget it. At the end of the day, the valves do some pretty crazy stuff even when the cams aren’t influencing them and you can’t remove many of the variables the car sees in a running condition. I’m not saying degreeing them is a waste of time, in fact I always degree my cams, but it’s not something I would obsess over.
     

    4K  0

    1995 Mitsubishi Eclipse GSX
    11.410 @ 125.490 · 2G DSM
    Loading...
  5. DSM_Kola

    DSM_Kola Probationary Member

    9
    1
    Joined Jun 28, 2019
    Franklin, Wisconsin
    Thanks for the information this at least puts me at ease a little bit being that this has happened to others. I kind of knew the main thing to worry about would be valve clearance because you don't want to bend a valve. One thing though, do you think I should leave the cams where they are at or should I make the timing events more aggressive because isn't the point of degree your cams to also get the most out of them?
     

    Road Race Build 225  1

    1995 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  6. DSMPT

    DSMPT Proven Member

    914
    479
    Joined Jun 12, 2014
    Japan / Mexico, Arizona
    This mostly happens when you don't set the dial gauge properly. While the cam is compressing the spring it reads fine but when the spring returns, that pushes and changes the dial gauge tip position a bit. Set the gauge the same angle/inline as valve and use a "L" shape tip and put it on a flat part of retainer, there is a tiny flat space on retainer under rocker arm where the valve keepers are. Normally I use that spot to set the gauge tip.

    As for the piston to valve clearance, that would depend on the shape of piston top, gasket thickness etc, too. Set the indicator properly and check again. The numbers would probably be more or less like those, so those numbers seem to be right to me.
     

    Drag Race Build 2K  3

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    Street Build 2K  4

    1998 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM
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  7. DSM_Kola

    DSM_Kola Probationary Member

    9
    1
    Joined Jun 28, 2019
    Franklin, Wisconsin
    I see what you are saying, I will give this a try and see what kind of results I get and I will double check the valve clearances. Also thanks for the advice
     

    Road Race Build 225  1

    1995 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
    DSMPT likes this.
  8. jed344

    jed344 Supporting VIP

    909
    131
    Joined Jan 10, 2008
    Waterville, Iowa
    I always respond to this type of stuff wit what GSC told me directly. Degreeing a 4g63 is easily done wrong. They told me find my max adjustment either way then install straight up and adjust them on the dyno. I find more cams make most power when they are adjusted for max vacuum at idle. So least amount of overlap. That being said i have played with adding overlap to help bring the boost in sooner and harder, example on say a auto car it can help spool it. I hope ya get it figure out but i do not even bother with degreeing anymore. Just check my piston to valve, and max adjustment. Toss them in and play with them.
     

    1K  38

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
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    Mello likes this.

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