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Post by viperlp01 on Aug 3, 2010 14:37:51 GMT -5
The only thing I can figure out is that the shim actaully rises the lifter up to help with the hydralics. But I still can't get my mind around to actually having a higher lift cam.. I can the duration being there..
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Post by streetnstrip on Aug 3, 2010 14:50:45 GMT -5
the overall lift will be affected, but i dont now by how much. what happens is the part of the roller on the lifter which cantacts the cam lobe moves, which will affect rocker ratio. shim the lifter and the cam contact patch moves counter clockwise on the roller. Raise the valve and it moves clockwise.. this would change lift but probably somthing like .005" so not really enough to notice.. so... dont u punks laugh at me, but i drew u a picture to illistrate the big issue when changing geometery.. look at how the rocker has to move across the valve in each situation... another thing to think about while looking at this, is that in any one of these situations the roller of lifter is moved, now with a regrind there is material removed from the base circle of the cam, thus you shim the lifter back up to make up the difference.. but as u can the loading of the valve throughout the travel is also affected. viper did you degree in your cams?? AJ, he is right, the ides of the shim is to keep the preload on the lifter in its proper operating range.. if the lifter is compressed to much, it could hold the valve open, not enough and it will tick. BTW paul drew that for me
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Post by streetnstrip on Aug 3, 2010 14:53:00 GMT -5
pual.. another time you will loose lift is if the lifter is fully pumped up, and the rocker doesnt contact the cam..
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Post by laser92 on Aug 3, 2010 14:58:26 GMT -5
mine is nice and quiet with no ticking, so I should be good then right?
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Post by streetnstrip on Aug 3, 2010 15:01:20 GMT -5
might not be perfect, but yeah, run it.
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Post by viperlp01 on Aug 3, 2010 15:48:48 GMT -5
I did not degree them. I just messed with the gears until I gained the most via dsmlink.. I am at -2ex/0 in... I might be switching cams soon. Maybe this winter. Delta makes a billit 272 kelford grind for 350 that i am thinking about trying out..
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Post by streetnstrip on Aug 3, 2010 15:57:33 GMT -5
I see, I wonder what they accually degree to.. it would be a useful bit of info from a tuning stand point, every combo is going to "like" a specific valve timing. Knowing what makes the most hp with yours, and then trying that same timing on another setup, it would be neat seeing how the different turbo/intake manifold reacts.. also, what you'll probably see if you messed with it enough, is that different boost levels will work better with different cam timing.. well maybe i guess.. that would depend on if your drive/boost preassure ratios are not linear with added boost or rpm... what were u looking at on link to come to your conclusion?
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Post by viperlp01 on Aug 3, 2010 16:42:47 GMT -5
70-90 times and hp estimates.. Same boost levels and target a/f. When I changed cam timing the car became less knock happy and I could add some timing. I am running e85. The car is NOTICABLY faster with that set up versus the two other I tried.. I also have another guy on tuners that tried my set up and he said it was the best for him as well. We are both running strokers.
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Post by streetnstrip on Aug 3, 2010 16:48:53 GMT -5
yeah thats cool man.. is he also running e85?
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Post by viperlp01 on Aug 3, 2010 17:28:44 GMT -5
That i dk?? He just said best gains were from my combo
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