LSK vs XE-R cams, is it worth the swap???
05-11-2006, 09:26 PM
#21
My cam is in my sig. I went with an LSK on the intake side because for everything I have heard is that a 2 valve engine likes more lift. I could be totally wrong, but I don't see how it can hurt either (provided the heads don't stall). The lobe I got should fit under the PRC dual on the ported LS6 heads (which don't stall from .600 to .650), will even take some shimming to get to .050 within coilbind to maintain pressure. I'm looking forward to getting it into the Z.
05-11-2006, 10:55 PM
#23
Try this link: https://ls1tech.com/forums/showpost....&postcount=300. Patrick has chassis dyno numbers for essentially the same engine (an AFR 225 346) with 234/238 114 XER, 231/236 112 LSK/XER, and a 223/227 110 LSK.
Spending $300 per set for springs should be the norm for a strong street/strip car. It is an amazment to me to see the endless discussions of $120 spring sets. A ridiculous place to cheap out.
Spending $300 per set for springs should be the norm for a strong street/strip car. It is an amazment to me to see the endless discussions of $120 spring sets. A ridiculous place to cheap out.
05-11-2006, 11:16 PM
#24
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Originally Posted by s346k
i'd like to see a back to back comparison of a cam with the same specs...ground on xe-r lobes and then lsk lobes. is it possible that just the lobes themselves could be worth 5-10 peak rwhp on stock heads/compression? or even more important...a few hundeds and/or tenth(s) at the track? as the lsk lobes would theoretically make more power virtually everywhere in the band. i wonder what kind of valve bounce effect is caused by the lsk lobes vs xe-r...closing the valve faster would cause more, correct? what kind of effect would that have on power output? when will we know the ramps are TOO aggressive?
224 LSK/236 XER
224 LSK
Lift Dur. Area
.006 275.3 28.68
.050 223.8 28.02
.200 149.6 23.61
236 XER
Lift Dur. Area
.006 286.3 28.76
.050 235.9 28.17
.200 155.4 23.04
05-11-2006, 11:41 PM
#25
FormerVendor
What we need to see are truly back to back tests the same days with the same conditions. I see little difference except the faster cams being a little better down low which is what they will shine at. I think the LSK should be best like I said if the springs are there to control it. You also have to think of how long these cams will last and what springs are around to work with them too.
05-11-2006, 11:49 PM
#26
FormerVendor
I'd love to do a 23X test with three different lobes and see what happens with great springs. Then do a torture test on a spintron to see how they all last as well. I would agree with Patrick G and eth otehrs that the LSK is a bad *** but will it last is another question. For all I know it may last longer but I'd love to know. At least we have this stuff and eth LSx platform already has a race car 55mm cam core!
05-12-2006, 06:55 AM
#27
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Originally Posted by racer7088
I'd love to do a 23X test with three different lobes and see what happens with great springs. Then do a torture test on a spintron to see how they all last as well. I would agree with Patrick G and eth otehrs that the LSK is a bad *** but will it last is another question. For all I know it may last longer but I'd love to know. At least we have this stuff and eth LSx platform already has a race car 55mm cam core!
05-12-2006, 07:29 AM
#29
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Originally Posted by DavidNJ
Why does everyone talk about the 921 and not the REV 8899 or 7790, Nextek 221423, Isky, Crower, etc. springs...all of whom have a high quality 400+#/in rate spring?
05-12-2006, 09:41 AM
#31
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Originally Posted by DavidNJ
Yes, they are all 1.29 or smaller.
Does Keith know you're quoting him?
Does Keith know you're quoting him?
05-12-2006, 11:49 AM
#32
I'm sure Keith doesn't mind, it is a dam good quote!
DAPSUPRSLO, the whole bleading off BMEP due to the cam is more in relation to the fucked up valve events in relation to the RPM and wave tuning. BMEP for a motor has the same curve as the TQ curve, so your going to peak BMEP at TQ peak and I guess it will "bleed" off till redline, but if you could hold that BMEP till redline your HP would never peak. As you can see I don't get that "bleeding" off BMEP thing at all. You might as well say you are bleeding off TQ, which is really odd as well.
Bret
DAPSUPRSLO, the whole bleading off BMEP due to the cam is more in relation to the fucked up valve events in relation to the RPM and wave tuning. BMEP for a motor has the same curve as the TQ curve, so your going to peak BMEP at TQ peak and I guess it will "bleed" off till redline, but if you could hold that BMEP till redline your HP would never peak. As you can see I don't get that "bleeding" off BMEP thing at all. You might as well say you are bleeding off TQ, which is really odd as well.
Bret
Last edited by SStrokerAce; 05-12-2006 at 12:08 PM.
05-12-2006, 11:51 AM
#33
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Originally Posted by SStrokerAce
I'm sure Keith doesn't mind, it is a dam good quote!
. I sent him a message on speedtalk anyway to confirm his consent.
05-12-2006, 12:12 PM
#34
Originally Posted by DavidNJ
Why does everyone talk about the 921 and not the REV 8899 or 7790, Nextek 221423, Isky, Crower, etc. springs...all of whom have a high quality 400+#/in rate spring?
Bret
05-12-2006, 01:16 PM
#35
FormerVendor
Yeah I see the LSK as a very nice lobe series but others have scared me as to how long it will last but I don't know if any of them know anything at all. I know the XERs with the good springs last great but with the crappier springs can break them here or there and I am sure the LSK can eat those springs or more.
05-12-2006, 02:45 PM
#36
Being able to use an aggressive cam is the edge between reliabilty and performance. The valve spring is the tradeoff. To spend a few hundred to run a race weekend, to spend several thousand to upgrade an engine, and to cheap out for $150 for a better valve spring seems ridiculous to me.
Those springs are all comparable in stiffness to the 921. To me, if the head can fit it, a 26055 or 26095 is the way to go.
.650 is no more lift with a good spring than .550 is with a junk one.
P.S.
I wasn't thinking of permission. More about surprise.
Those springs are all comparable in stiffness to the 921. To me, if the head can fit it, a 26055 or 26095 is the way to go.
.650 is no more lift with a good spring than .550 is with a junk one.
P.S.
I wasn't thinking of permission. More about surprise.
05-12-2006, 03:05 PM
#37
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Originally Posted by DavidNJ
Being able to use an aggressive cam is the edge between reliabilty and performance. The valve spring is the tradeoff. To spend a few hundred to run a race weekend, to spend several thousand to upgrade an engine, and to cheap out for $150 for a better valve spring seems ridiculous to me.
Those springs are all comparable in stiffness to the 921. To me, if the head can fit it, a 26055 or 26095 is the way to go.
.650 is no more lift with a good spring than .550 is with a junk one.
P.S.
I wasn't thinking of permission. More about surprise.
Those springs are all comparable in stiffness to the 921. To me, if the head can fit it, a 26055 or 26095 is the way to go.
.650 is no more lift with a good spring than .550 is with a junk one.
P.S.
I wasn't thinking of permission. More about surprise.
05-12-2006, 03:53 PM
#38
I think this has been mentioned earlier in the post but looking at the Comp Cams lobe charts it looks like the XFI lobes are in between the XE-R and the LSK lobes. The XFI lobes might be a good route to go. It would be interesting to see a head to head comparison between the three.
05-12-2006, 06:06 PM
#39
Originally Posted by DavidNJ
Being able to use an aggressive cam is the edge between reliabilty and performance. The valve spring is the tradeoff. To spend a few hundred to run a race weekend, to spend several thousand to upgrade an engine, and to cheap out for $150 for a better valve spring seems ridiculous to me.
Those springs are all comparable in stiffness to the 921. To me, if the head can fit it, a 26055 or 26095 is the way to go.
.650 is no more lift with a good spring than .550 is with a junk one.
P.S.
I wasn't thinking of permission. More about surprise.
Those springs are all comparable in stiffness to the 921. To me, if the head can fit it, a 26055 or 26095 is the way to go.
.650 is no more lift with a good spring than .550 is with a junk one.
P.S.
I wasn't thinking of permission. More about surprise.