lift
03-19-2002, 12:39 AM
#2
Launching!
Join Date: Dec 2001
Location: Houston
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Re: lift Well it's actruly said it's better to to have lift with the Rockers in some situation you have too when using the rockers some really weird but cool stuff happen with the valve train geometry. In the LS1 case it's easy to use the cam.
<small>[ March 19, 2002, 12:43 AM: Message edited by: One Monkey ]</small>
<small>[ March 19, 2002, 12:43 AM: Message edited by: One Monkey ]</small>
03-19-2002, 09:28 AM
#4
Re: lift lift at the valve or the .500" is what you are talking about. If you had 1.6:1 Rockers then you would have a cam with .3125" lift at the lobe. If you had 1.7:1 then the lift at the cam would be .294"
So as far as performance goes with all other things being equal it's too small to find. Because the testing tolerances could eat up the difference.
The larger Rocker Arm though will add duration to the cam since it will make the cam raise faster, and at the magical .050 lift you will have more duration.
Now another thought would be that the cam with a lower lift could dwell at that lift for longer since the velocity(ramps of the cam lobe) of the high lift cam could be copied to the low lift cam and the acutal area under the curve of the lobes would be larger. Now that would take a expensive race valveterrain but you could do it.
So basicly when you have unlimited money what's better right? It all depends but if I was looking for lots of lift at a low duration (as in a street car) I would want as much lift from the cam as I could get coupled with the rocker arm. So for a LS1 say a 222/222 @ .050" with .333/.333 lift I would love to have 1.8:1 Rocker Arms so I could .600 lift at the valve to really use the potential of ported LS1 heads.
I hope that helps.
Bret
So as far as performance goes with all other things being equal it's too small to find. Because the testing tolerances could eat up the difference.
The larger Rocker Arm though will add duration to the cam since it will make the cam raise faster, and at the magical .050 lift you will have more duration.
Now another thought would be that the cam with a lower lift could dwell at that lift for longer since the velocity(ramps of the cam lobe) of the high lift cam could be copied to the low lift cam and the acutal area under the curve of the lobes would be larger. Now that would take a expensive race valveterrain but you could do it.
So basicly when you have unlimited money what's better right? It all depends but if I was looking for lots of lift at a low duration (as in a street car) I would want as much lift from the cam as I could get coupled with the rocker arm. So for a LS1 say a 222/222 @ .050" with .333/.333 lift I would love to have 1.8:1 Rocker Arms so I could .600 lift at the valve to really use the potential of ported LS1 heads.
I hope that helps.
Bret
03-19-2002, 10:57 AM
#5
Re: lift I was basically trying to see if I could use the rockers to tailor my cam specs even more. I wanted to get something from Comp Cams with their Extreme lobes, but choices are very limited. So I figured I get the duration I want and then get the rockers on top of it to increase the lift as much as I want. I can get anywhere from 1.6 to 1.9 made.
So lets say I got 240/240 but lift is only .500/.500. I could then use the rockers to make it .550/.550. There I got the duration and lift I want, but is it the same as having a cam with 240/240 .550/.550?
So lets say I got 240/240 but lift is only .500/.500. I could then use the rockers to make it .550/.550. There I got the duration and lift I want, but is it the same as having a cam with 240/240 .550/.550?
