cam gurus: thought on this
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Joined: May 2006
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From: Metairie, LA
cam gurus: thought on this I'm throwing around ideas for a custom cam for my 95 TA. I'm looking for an rpm range of 2000-2500 to 6500, give or take. Something with good power under the curve. Overlap centered about TDC to build power past peak and around 8.5 DCR. I chose a single pattern cam b/c I don't particularly want lope and from the heads to the tailpipe the exhaust is aftermarket. Here's what I've come up with:
@.050 232/232 .565/.575 111LSA +1
IVO 6
IVC 46
EVO 48
EVC 4
OVERLAP- 10*
@.006 284/282 ?/? 111 LSA +1
IVO 32
IVC 73
EVO 73
EVC 29
OVERLAP-61
Maybe asymmetric lobes. More aggressive ramp rates on closing than opening. This is mainly to help the overlap. That way the exhaust valve is shutting quicker while the intake is opening slower, to push overlap closer to TDC. Overlap is 6* exhaust stroke, 4* intake stroke @.050. Lift #s are with 1.6rr, btw. I think the tight LSA will also help with power under the curve. I come up with a DCR of about 8.38, a little lower than hoped for, but if I advance anymore, the overlap will move more towards the exhaust stroke.
Thoughts, opinions, suggestions are greatly appreciated. Thanks!
@.050 232/232 .565/.575 111LSA +1
IVO 6
IVC 46
EVO 48
EVC 4
OVERLAP- 10*
@.006 284/282 ?/? 111 LSA +1
IVO 32
IVC 73
EVO 73
EVC 29
OVERLAP-61
Maybe asymmetric lobes. More aggressive ramp rates on closing than opening. This is mainly to help the overlap. That way the exhaust valve is shutting quicker while the intake is opening slower, to push overlap closer to TDC. Overlap is 6* exhaust stroke, 4* intake stroke @.050. Lift #s are with 1.6rr, btw. I think the tight LSA will also help with power under the curve. I come up with a DCR of about 8.38, a little lower than hoped for, but if I advance anymore, the overlap will move more towards the exhaust stroke.
Thoughts, opinions, suggestions are greatly appreciated. Thanks!
Last edited by eLTwerker; Jan 27, 2007 at 07:33 AM.
Moved from advanced tech section. You'll get more views in here than the LT1 section too.
__________________
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.
Originally Posted by eLTwerker
I'm throwing around ideas for a custom cam for my 95 TA. I'm looking for an rpm range of 2000-2500 to 6500, give or take. Something with good power under the curve. Overlap centered about TDC to build power past peak and around 8.5 DCR. I chose a single pattern cam b/c I don't particularly want lope and from the heads to the tailpipe the exhaust is aftermarket. Here's what I've come up with:
@.050 232/232 .565/.575 111LSA +1
IVO 6
IVC 46
EVO 48
EVC 4
OVERLAP- 10*
@.006 284/282 ?/? 111 LSA +1
IVO 32
IVC 73
EVO 73
EVC 29
OVERLAP-61
Maybe asymmetric lobes. More aggressive ramp rates on closing than opening. This is mainly to help the overlap. That way the exhaust valve is shutting quicker while the intake is opening slower, to push overlap closer to TDC. Overlap is 6* exhaust stroke, 4* intake stroke @.050. Lift #s are with 1.6rr, btw. I think the tight LSA will also help with power under the curve. I come up with a DCR of about 8.38, a little lower than hoped for, but if I advance anymore, the overlap will move more towards the exhaust stroke.
Thoughts, opinions, suggestions are greatly appreciated. Thanks!
@.050 232/232 .565/.575 111LSA +1
IVO 6
IVC 46
EVO 48
EVC 4
OVERLAP- 10*
@.006 284/282 ?/? 111 LSA +1
IVO 32
IVC 73
EVO 73
EVC 29
OVERLAP-61
Maybe asymmetric lobes. More aggressive ramp rates on closing than opening. This is mainly to help the overlap. That way the exhaust valve is shutting quicker while the intake is opening slower, to push overlap closer to TDC. Overlap is 6* exhaust stroke, 4* intake stroke @.050. Lift #s are with 1.6rr, btw. I think the tight LSA will also help with power under the curve. I come up with a DCR of about 8.38, a little lower than hoped for, but if I advance anymore, the overlap will move more towards the exhaust stroke.
Thoughts, opinions, suggestions are greatly appreciated. Thanks!
Personally, the cams you came up with just don't look right to me...especially for your idea of low lope. Also, i'm not even gonna make an effort with the big cam you have listed. What I did was tweak the small cam to come up with a much better cam.
228/232 .639/.575 111+2
"Why?" you may ask...The LSK lobed intake side will probably make the same power as your original less aggresive 232 lobe. This allows you to bring overlap down and to advance the cam keeping overlap close to center. And since the cam is advanced, your DCR comes up. So now you have:
IVO: 5
IVC: 43
EVO: 49
EVC: 3
overlap: 8
If you want the original 10 degrees of overlap, then go to a 110+1
IVO: 5
IVC: 43
EVO: 47
EVC: 5
Overlap: 10
And to shift power even further to the left, a 110+2
IVO: 6
IVC: 42
EVO: 48
EVC: 4
overlap: 10
The last one I listed is probably your best choice unless you want slightly less lope which comes with the first.
Hammer
Last edited by thehammer69; Jan 27, 2007 at 11:36 AM.
Thread Starter
TECH Enthusiast
Joined: May 2006
Posts: 631
Likes: 0
From: Metairie, LA
I appreciate your time man. However, I only have one cam listed. Just listed the valve events @ .050 and .006 seperately. Those look like great suggestions. I like it a 110 +2 the best. Overlap basically centered about TDC and an IVC @ 42* will give me a DCR of about 8.5. Only problem I see is the lift is way too high on the intake lobe to run to 6500. What do you think about the intake lobe being @ .570 or so?
P.s> This is for an LT1
P.s> This is for an LT1
Originally Posted by eLTwerker
I appreciate your time man. However, I only have one cam listed. Just listed the valve events @ .050 and .006 seperately. Those look like great suggestions. I like it a 110 +2 the best. Overlap basically centered about TDC and an IVC @ 42* will give me a DCR of about 8.5. Only problem I see is the lift is way too high on the intake lobe to run to 6500. What do you think about the intake lobe being @ .570 or so?
P.s> This is for an LT1
P.s> This is for an LT1
Oh, and I didn't know you were asking about an LT1...that have different cam specs so toss my idea out since it is LS based.
Hammer
