Overlap Formula
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From: BFE
Originally Posted by Beast96Z
Either formula above nets the same end result.
Let us say 224/224 114lsa @ .050
so first formula (224+224/4)- (2x114)= -116
Second formula (224+224/2)- (2x114)= -4
How are these results the same??
Originally Posted by PREDATOR-Z
Let us say 224/224 114lsa @ .050
so first formula (224+224/4)- (2x114)= -116
Second formula (224+224/2)- (2x114)= -4
How are these results the same??
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So, do I want overlap to be closer to zero or further away? With my current cam I'm getting -14*, which performs great and sounds very badass. Then one of the ones I'm looking at for my LS1 (218/222-113) is -6* and the other one I'm looking at (220/224-113) is -4*. The -6* would give more lope of these two, right?
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Verdad Gallardo TECH Senior Member
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From: BFE
Originally Posted by 99silveradoSS
So, do I want overlap to be closer to zero or further away? With my current cam I'm getting -14*, which performs great and sounds very badass. Then one of the ones I'm looking at for my LS1 (218/222-113) is -6* and the other one I'm looking at (220/224-113) is -4*. The -6* would give more lope of these two, right?
(-) less lope
(+) more lope
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From: Bossier City, LA
Originally Posted by PREDATOR-Z
The less overlap the less lope.
(-) less lope
(+) more lope
(-) less lope
(+) more lope
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Quick and Dirty Cam Calculator Spreadsheet
0.050
Intake Duration - ID 220
Exhaust Duration - ED 224
Lobe Center Angle - LCA (also known as LSA) 113
Intake Centerline - ICL 113
Intake Valve opens - IVO -3
Intake Valve closes - IVC 43
Exhaust Valve Opens - EVO 45
Exhaust Valve Closes - EVC -1
Exhaust Centerline - ECL 113
Overlap -4
Quick and Dirty Cam Calculator Spreadsheet
0.050
Intake Duration - ID 218
Exhaust Duration - ED 222
Lobe Center Angle - LCA (also known as LSA) 113
Intake Centerline - ICL 113
Intake Valve opens - IVO -4
Intake Valve closes - IVC 42
Exhaust Valve Opens - EVO 44
Exhaust Valve Closes - EVC -2
Exhaust Centerline - ECL 113
Overlap -6
Neither should have much lope... The second one will have less though if any...
0.050
Intake Duration - ID 220
Exhaust Duration - ED 224
Lobe Center Angle - LCA (also known as LSA) 113
Intake Centerline - ICL 113
Intake Valve opens - IVO -3
Intake Valve closes - IVC 43
Exhaust Valve Opens - EVO 45
Exhaust Valve Closes - EVC -1
Exhaust Centerline - ECL 113
Overlap -4
Quick and Dirty Cam Calculator Spreadsheet
0.050
Intake Duration - ID 218
Exhaust Duration - ED 222
Lobe Center Angle - LCA (also known as LSA) 113
Intake Centerline - ICL 113
Intake Valve opens - IVO -4
Intake Valve closes - IVC 42
Exhaust Valve Opens - EVO 44
Exhaust Valve Closes - EVC -2
Exhaust Centerline - ECL 113
Overlap -6
Neither should have much lope... The second one will have less though if any...
Some people think that LSA determines overlap.
Overlap is amount of time the exhaust lobe and intake lobe overlap each other. LSA is only a small component of this. Duration counts much more.
For example
210/216 106LSA cam = 1 degree of overlap at .050"
220/226 110LSA cam = 3 degrees of overlap at .050"
230/236 114LSA cam = 5 degrees of overlap at .050"
So even though my LSA got 4 degrees wider in each successive cam, the overlap grew as well. LSA and overlap do not necessarily go hand in hand.
Overlap is amount of time the exhaust lobe and intake lobe overlap each other. LSA is only a small component of this. Duration counts much more.
For example
210/216 106LSA cam = 1 degree of overlap at .050"
220/226 110LSA cam = 3 degrees of overlap at .050"
230/236 114LSA cam = 5 degrees of overlap at .050"
So even though my LSA got 4 degrees wider in each successive cam, the overlap grew as well. LSA and overlap do not necessarily go hand in hand.
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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.
