Generation III Internal Engine 1997-2006 LS1 | LS6
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Old May 10, 2005 | 09:45 PM
  #21  
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Yes, that's pretty much the concept.

IE:
240/240 Duration & 600/610 Lift at 112 Lobe Seperation.

240/240 Duration & 600/610 Lift at 114 Lobe Seperation.

The 112 LSA would have more overlap if the valve timing was the same.
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Old May 10, 2005 | 09:55 PM
  #22  
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Originally Posted by waterbug1999
So, given the numbers are the same.. Typically the 112 will "lope" more?

2??/2?? Duration & 600/610 Lift at 112 Lobe Seperation.
2??/2?? Duration & 600/610 Lift at 114 Lobe Seperation.

And if this is the G5X3.. Then how bigger could the G5X4 be?
X4 is big. Probably not as big as the Trex, but in the ballpark. That's my guess. Given equal durations the lower LSA will idle rougher. (more lope)

The equation for overlap (at a specific lift, most durations used are at .05" lift) is:
((Intake duration + exhaust duration) divided by 4), minus LSA, then multiplied by two.
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Old May 10, 2005 | 10:12 PM
  #23  
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Well, i have seen a dyno graph of the t-rex. It seems to look like it ramps up quick and then kind of falls off (hp) but the TQ seems to hang in there. Looks like it might not be that streetable of a cam.
What does the curves look like on the other "big" cams? Magic Stick, G5X3, etc.
I have been looking around but have not stumbled on any of them yet. Thanks

Last edited by waterbug1999; May 11, 2005 at 03:03 AM.
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Old May 10, 2005 | 10:14 PM
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Most of the big cams don't come on until 4,000 rpm, maybe even 4,500, and carry into the upper 6k range at the least.
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Old May 11, 2005 | 12:32 AM
  #25  
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Also keep in mind that some cams will fit on stock heads at 114 lsa without flycutting and some won't at 112.
With G5X3 for example, it is preferable to flycut on a 112.
It will fit but the PTV tolerances are suicidal for the street.
PTV acceptable tolerance depend on how gutsy the owner is.

The amount of overlap is what determines how far you can go before running on vacuum issues with A4, as stated above. This is largely due to the intake shape we run on the LSx motors.
In Aussie land, they have solved that with pretty nifty ITB set ups and are able to run very tight lsa's (106 is the one I heard), that idle like a baby 224 with our intakes.
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Old May 11, 2005 | 02:09 AM
  #26  
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ITB? Sorry, Im dumb...
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Old May 11, 2005 | 03:00 AM
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I think he's referring to the individual throttle bodies for each cylinder.
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Old May 11, 2005 | 03:05 AM
  #28  
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Originally Posted by luv2spd
I think he's referring to the individual throttle bodies for each cylinder.
How does that work? 8 TB's? Sorry, Im dumb too.
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Old May 11, 2005 | 05:52 AM
  #29  
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I found the link with a vid:

Here is a video 242/242 106 LSA 105 ICL idling @ 875-925...
http://users3.ev1.net/~black_ops/video/242-106.mpg
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Old May 11, 2005 | 06:52 AM
  #30  
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Re the video:

Is that a FI setup, or carbs with velocity stacks?



I can't tell from the video, it's too small and blury.

I don't like the idle much.
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Old May 11, 2005 | 08:50 AM
  #31  
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That is FI,
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