lsk lobe lift limitations...
lsk lobe lift limitations... ok, so i've been researching comp's cam lobes. it appears that some of the unique lobes have lift / duration limitations. the xfi lobes for example, can't be ground on just any duration + lift combo. do the lsk lobes follow suit in that respect? i've read conflicting stories - that lsk lobes can't be used under .600 lift and vice versa. so which is it? i do believe that ls1/6 heads have a point of diminishing returns, which encourages me to knock my intended amount of valve lift DOWN, with aiding the survival of my lifters in mind. upon swapping heads, i will step up to an as cast ls6 head, possibly MINOR port work at most...and naturally lifter replacement, as well.
LSK lobes were designed to be easier on lifters than XE-R lobes. Here's how Comp did it:
Slower ramps from .006" to .050" means softer valve drops to the seats with less bounce.
Higher lift means the lifter follows more of an arc that it naturally wants to go instead of the tendancy to LOFT off the nose of the cam in more "square" configurations like the XE-R or XFI lobes. Lofting the lifter shortens life and brings on obvious valve control issues.
So in a nutshell, the LSK lobes were initially developed to overcome some of the problems with other lobes. Why Comp doesn't carry them in their catalog is beyond me.
Oh, and one last thing...
With a two valve configuration, curtain area is your friend...lift is your friend. You'll have to go a lot further than .600 lift to get diminishing returns with stock LS1/LS6 heads.
Slower ramps from .006" to .050" means softer valve drops to the seats with less bounce.
Higher lift means the lifter follows more of an arc that it naturally wants to go instead of the tendancy to LOFT off the nose of the cam in more "square" configurations like the XE-R or XFI lobes. Lofting the lifter shortens life and brings on obvious valve control issues.
So in a nutshell, the LSK lobes were initially developed to overcome some of the problems with other lobes. Why Comp doesn't carry them in their catalog is beyond me.
Oh, and one last thing...
With a two valve configuration, curtain area is your friend...lift is your friend. You'll have to go a lot further than .600 lift to get diminishing returns with stock LS1/LS6 heads.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
thanks for the response. i understand the differences of the lobes, but i didn't understand why some were "limited use applications"...and comp was no help. they kept telling me i couldn't get that lobe on an ls1 cam, the one that told me i could said i couldn't use it above 224* duration - all kinds of jargain.
so it appears i should stick to my initial plan and cam the hell out of my little 346, primarily relying on the theory (thus far) associated with lsk lobes. the only thing i'm afraid of is popping a lifter before i get a chance to upgrade.
so it appears i should stick to my initial plan and cam the hell out of my little 346, primarily relying on the theory (thus far) associated with lsk lobes. the only thing i'm afraid of is popping a lifter before i get a chance to upgrade.
XFI lobes seem to be good in the smaller durations, but when the durations approach the 230s, they don't seem to be as stable as the LSK or XE-R lobes.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Your first problem was talking to Comp. There tech helpers are mentally challenged and reading from a script. They'd be lucky to know what a cam is. Your best bet will be to call a reputable cam designer and see what they think. Sticking with the LSK/XE-R lobes is deffinatlly gunna be your best bet.
