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cam question

Discussion in '3sge' started by jwagner162, Mar 29, 2011.

  1. jwagner162

    jwagner162 Well-Known Member Donated!

    ok. i understand the cam thing but am a bit amiss on what my new cams are. i have the sheet. i guess im just looking to figure out how what amount of lift gives me the "advertised" duration.

    -i know stock cams are 240/240, but at what lift?

    -if i go with what ive been reading it would be at .006 ??? that would mean i have 279.3/275.8 cams.

    -can anyone help me understand this better? i understand what the measurements are and how it all works, i just have a sheet with a boat load of numbers and am wondering how i get the dumbed down advertised duration.
  2. Stig

    Stig ST162 Guru Donated!

    You can't change the duration
    Watch the lift on these - gen2 has bigger shims and gen3 is under bucket.

    I'll post specs once I'm back at my computer, later have slightly more duration but
    a lot more lift
  3. Stig

    Stig ST162 Guru Donated!

    As you can see the durations went up slightly but the lift was increased a lot

    1st gen 3SGE (160hp)
    IN: 240deg, 7.2mm lift, (timing 5/55)
    EX: 240deg 7.2mm lift, (timing 55/5)

    1st gen 3SGTE
    IN: 232deg, 7.15 lift, (timing 4/48)
    EX: 232deg, 7.15 lift, (timing 48/4)

    2nd gen 3SGE (165hp):
    In: 244deg, 8.5mm lift (timing 7/57)
    Ex: 244deg, 8.5mm lift (timing 57/7)

    2nd gen 3SGTE (225hp):
    In: 236deg, 8.2mm lift (timing 8/4)
    Ex: 236deg, 8.2mm lift (timing 56/0)

    3rd gen 3SGE A/T (170hp):
    In: 240deg, 8.7mm lift (timing 7/53)
    Ex: 240deg, 8.2mm lift (timing 53/7)

    3rd gen 3SGE M/T (180hp):
    In: 252deg, 9.8mm lift (timing 7/65)
    Ex: 240deg, 8.2mm lift (timing 53/7)

    3rd gen 3SGTE (245hp):
    In: 240deg, 8.7mm lift (timing 7/53)
    Ex: 236deg, 8.2mm lift (timing 50/6)

    Better explation here- http://st162.net/forums/viewtopic.php?f=101&t=6934&p=94731#p94731
  4. jwagner162

    jwagner162 Well-Known Member Donated!

    could that be a lifter change or are they all shim under?

    mine are at 8.4mm lift.
  5. Stig

    Stig ST162 Guru Donated!

    Other thread has lifter details

    For these I'd say you need shim under or solid lifters + stiffer spings

    Mafix has done a lot of research on this, let's see what he says
  6. Mafix

    Mafix Owner Staff Member Administrator Donated!

    no it's all cam. you can't change the lifter to gain lift. you'll wipe the cam out.
    gen1 and 2 are shim over bucket. you want either shim under bucket or shimless.
    there are so many little things with cams it's not funny. i'll explain more later.
  7. Mafix

    Mafix Owner Staff Member Administrator Donated!

    ok got some time.
    duration is the total time the valve is open. lobe center is the time the valve is either 100% closed or 100% open. lift it the maximum amount of valve opening. the key to making power with a cam is overlap (exhaust lobe center vs intake lobe center) and lift. the duration isn't the most important thing. there is also a term called ramp which is how fast the valve opens and closes during duration with lobe center taken into account. what i've found:
    long duration = shitty idle, doesn't require high lift, extremely important overlap and lobe centers
    short duration = crap. that is all.
    too much overlap = horrid power. like having an egr valve stuck open.
    not enough overlap = motor destroyer
    lobe center is a constant and is never 0 and 180 degrees. this is a needed number to setup the cams properly
    high lift = great for power but wears on valve train faster and can make a motor interference
    low lift = crappy power, long life on all valve train components (most O.E.)
    high ramp = very snappy power, if done properly can make tons of power, cams must be set properly with overlap in consideration <---very important, if done incorrectly your motor can become a bomb, high valve train wear
    low ramp = most O.E.

    i hope that helps. remember with more duration you have to bump the idle higher and higher. from memory the toyota atlantic series race 3sge used toda 320 duration 11.5 lift cams and idled at 3K rpm (do note it redlined at 13K rpm)

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