in a nutshell, 976/l92/l99 AFM with Cam phasing
07-14-2009, 09:22 AM
#1
Launching!
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in a nutshell, 976/l92/l99 AFM with Cam phasing rather than endless piece-by-piece searching, maybe someone who has done this can harp on in.
cam swaps on these automatic-transmissioned Gen IV engines with the compu gizmos:
here's what I think I know:
--they have lifters that deactivate cylinders. these lifters are heavier.
--they can have a cam swap as long as the phasing is limited to around 20 degrees to avoid interference.
--cam swaps and headers can turn these engines effectively into ls3's as they carry the same heads and are only slightly smaller bore.
--the transmission ends up wigging a bit with cam mods.
here's what I don't know:
--do lifters need to be removed for cam swaps involving high lift profiles? are heavy mass lifters just too much for the increased ramp rates??
--springs and pushrods necessitated for the swap??
--are the new offset rockers capable of handling high lifts without losing over to a non-intended wear area on the nose of the rocker??
--can computer tuning can produce acceptable results
--how can the transmission be acceptably tuned??
cam swaps on these automatic-transmissioned Gen IV engines with the compu gizmos:
here's what I think I know:
--they have lifters that deactivate cylinders. these lifters are heavier.
--they can have a cam swap as long as the phasing is limited to around 20 degrees to avoid interference.
--cam swaps and headers can turn these engines effectively into ls3's as they carry the same heads and are only slightly smaller bore.
--the transmission ends up wigging a bit with cam mods.
here's what I don't know:
--do lifters need to be removed for cam swaps involving high lift profiles? are heavy mass lifters just too much for the increased ramp rates??
--springs and pushrods necessitated for the swap??
--are the new offset rockers capable of handling high lifts without losing over to a non-intended wear area on the nose of the rocker??
--can computer tuning can produce acceptable results
--how can the transmission be acceptably tuned??
07-14-2009, 06:43 PM
#2
here's what I don't know:
--do lifters need to be removed for cam swaps involving high lift profiles? are heavy mass lifters just too much for the increased ramp rates??
--springs and pushrods necessitated for the swap??
--are the new offset rockers capable of handling high lifts without losing over to a non-intended wear area on the nose of the rocker??
--can computer tuning can produce acceptable results
--how can the transmission be acceptably tuned??
2. Springs are required, pushrods are an extremely good idea.
3. Stock rockers will take whatever you throw at them for the most part.
4. YES, you can tune them. Comp made a 70hp (430hp to 500hp) gain and didnt loose any torque anywhere on a almost stock L92 (had headers) with only a cam and springs swap.
5. The trans is just like any other. line pressures, shift points, etc, etc...
07-15-2009, 10:03 PM
#3
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1. YOu have to change the lifters, 100%. Its not the weight, its that when deactivated anthing over .500 lift wont actually deactivate them. Ive read that they still open.
2. Springs are required, pushrods are an extremely good idea.
3. Stock rockers will take whatever you throw at them for the most part.
4. YES, you can tune them. Comp made a 70hp (430hp to 500hp) gain and didnt loose any torque anywhere on a almost stock L92 (had headers) with only a cam and springs swap.
5. The trans is just like any other. line pressures, shift points, etc, etc...
2. Springs are required, pushrods are an extremely good idea.
3. Stock rockers will take whatever you throw at them for the most part.
4. YES, you can tune them. Comp made a 70hp (430hp to 500hp) gain and didnt loose any torque anywhere on a almost stock L92 (had headers) with only a cam and springs swap.
5. The trans is just like any other. line pressures, shift points, etc, etc...
07-16-2009, 05:42 AM
#4
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There are a couple of performance cam's out for the AFM (DOD) engines with the LS3 heads.
New Era has both a Low lift and a high lift cam package under the G8 section on there web site.
You can tune the trans for most of the issues but a higher stall torque converter is usually required with larger cams shafts on automatics.
New Era has both a Low lift and a high lift cam package under the G8 section on there web site.
You can tune the trans for most of the issues but a higher stall torque converter is usually required with larger cams shafts on automatics.
