Too much DCR?
#1
Too much DCR?
I used the calculator at United Machine, which seems to be pretty simple, and the results were a bit disturbing, to say the least. Mike @ TEA told me the heads are OTW, so install time is soon. The numbers I came up with are kind of scary, so I'm hoping I did it wrong. The particulars are stock LS6 bottom, heads milled to 61cc, and Cometic .040 gaskets. The cam is a Crane 228/232 .600/.600 @ 112 LSA +0 advance. The cam card says intake closes at 45.0 ABDC @ .050 lift and 236 Deg. duration. Advertised duration is 298/302 at 80.0 ABDC and .004 lift. I'd sure appreciate any help/suggestions, as the calculator said static was 11.3, which is not too bad, but DCR worked out to 10.2.
#2
LS1 Tech Administrator
iTrader: (14)
Your calculator uses duration at .006". You're using duration at .004". Big difference sometimes. Try plugging in 278/282 for the duration at .006". With .600" lift, the grind is very close to a Comp XE-R lobe in valve action, so just add 50 degrees to the duration at .050" to get the duration at .006".
__________________
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.
#6
LS1 Tech Administrator
iTrader: (14)
Wow, those lobes are pretty lazy compared to Comps.
__________________
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.
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#8
Crane calls it their Z-cam line, and it's the most aggresive lobe they have? I'm still not getting this, because I tried the thing again, and still come up with different values that everybody elso, i.e. SCR (now) 11.02 and DCR 9.1.
Is it safe to assume the values I'm using for piston head volume (0), and deck clearance of .007, are correct for my LS6? I assumed LS1-6 were the same?
Is it safe to assume the values I'm using for piston head volume (0), and deck clearance of .007, are correct for my LS6? I assumed LS1-6 were the same?
#9
TECH Veteran
iTrader: (21)
Originally Posted by exSSer
Crane calls it their Z-cam line, and it's the most aggresive lobe they have? I'm still not getting this, because I tried the thing again, and still come up with different values that everybody elso, i.e. SCR (now) 11.02 and DCR 9.1.
Is it safe to assume the values I'm using for piston head volume (0), and deck clearance of .007, are correct for my LS6? I assumed LS1-6 were the same?
Is it safe to assume the values I'm using for piston head volume (0), and deck clearance of .007, are correct for my LS6? I assumed LS1-6 were the same?
Assuming you have a stock short you should enter:
61cc's
0
.040
3.910
3.898
-.007
3.622
6.100 (guessing on rod legnth)
77* IVC
#10
Originally Posted by Beast96Z
Cranes most aggressive is still fairly lazy compared to Comps. I'm using the same calculator as you, but the number one thing I can see, is that you need to enter -.007" for your deck height.
Assuming you have a stock short you should enter:
61cc's
0
.040
3.910
3.898
-.007
3.622
6.100 (guessing on rod legnth)
77* IVC
Assuming you have a stock short you should enter:
61cc's
0
.040
3.910
3.898
-.007
3.622
6.100 (guessing on rod legnth)
77* IVC
OK, thanks. I plugged in your numbers and got SCR of 11.5, and DCR or 8.2. Two more stupid questions. Would these be OK on 92 oct, and how did you arrive at the 77* number for IVC? The Crane card says @ .050 lift, the IVC is 45 deg and 236 duration, and if I add 15 to this I get only 60*. It seems the IVC number is vitally important to these calcs, and also the most elusive.
#12
LS1 Tech Administrator
iTrader: (14)
Using J-Rod's calculator, I come up with 11.30:1 SCR and 8.05:1 DCR. I trust this DCR figure based on how it compares to other cams of comparable duration, LSA, and ICL.
__________________
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.
#13
Thanks for the help, guys. I don't have Excell, so I can't use the calculators based on that, and the one @ united machine doesn't even use duration numbers, just IVC @ .050 plus 15*. Since everything depends on this number to make the DCR, that # is easily skewed.(screwed) If that SCR is OK with pump gas, I guess I'll stick with the Cometics, and not use the MLS GM gaskets.
#14
LS1 Tech Administrator
iTrader: (14)
If your pistons are not flycut, you may run into P to V problems with 290/294 @ .006". Be sure to check before you turn over the motor.
__________________
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.
#15
TECH Fanatic
The united machine calc assumes 0.006 duration I believe, it says at 15* as an approximation. What you should really do is put in the 0.006 duration, which is what I think Beast96Z did for you.
#16
Originally Posted by Patrick G
If your pistons are not flycut, you may run into P to V problems with 290/294 @ .006". Be sure to check before you turn over the motor.
The heads are the Trickflows, which give more PTV. Anyway, TEA said they'd work. We brainstormed the pkg, and came up originally with 10.6 SCR, so decided to mill to 61.(from 64)
Just don't want to screw it all up with the wrong cam. I was going for a good low-end, but even better mid range, with decent drivability, and a mild lope. Car's NOT a racer, but a weekend plaything/ occaisional short trip car. ('02 ZO6)
#17
TECH Veteran
iTrader: (21)
Originally Posted by exSSer
Actually the 290/294 is at .004 via Crane.
#18
Originally Posted by Beast96Z
In your first post, you said advertised at .004" was 298/302. No were on Cranes sight did I see it say the 290/294 was at .004". Going by Cranes lobe profiles, the 290/294 seems about right for .006". To get the IVC I was using, use the IVC calculator. 294 divided by 2, plus ICL, minus 180, equals IVC @ .006".
#19
LS1 Tech Administrator
iTrader: (14)
That gets me back to my original post of 278/282.
__________________
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.