9.52 Dynamic Compression ratio, that cant be right what am i calculating wrong?
07-13-2008, 09:43 AM
#1
9.52 Dynamic Compression ratio, that cant be right what am i calculating wrong? I was just curious what my SCR and DCR were so i started searching and calculating this morning and with two different calculaters i have come up with about the same numbers.
SCR 10.35
DCR 9.52
I used the one calculator to get my dynamic stroke length which was
3.2993353100821 and then i put that number in where the origional stroke length was and came up with 9.52. Was that wrong?
I used
Bore: 3.8976"
Stroke: 3.622"
rod length: 6.098"
deck: -.007" (piston extends above block deck)
stock gasket thickness - .053
stock gasket bore - 3.905
stock 241 cc - 66.67
stock piston cc - 0
intake valve closing angle - 43
dynamic stroke length - 3.2993353100821
9.52 just seems pretty high for me.
*edit* i just switched out my "advertised duration" from the dynamic stroke calculater from using the 235/235@ .050 to using the 285/285 @ .006 and i came up with 8.00 for dynamic, does that sound about right?
SCR 10.35
DCR 9.52
I used the one calculator to get my dynamic stroke length which was
3.2993353100821 and then i put that number in where the origional stroke length was and came up with 9.52. Was that wrong?
I used
Bore: 3.8976"
Stroke: 3.622"
rod length: 6.098"
deck: -.007" (piston extends above block deck)
stock gasket thickness - .053
stock gasket bore - 3.905
stock 241 cc - 66.67
stock piston cc - 0
intake valve closing angle - 43
dynamic stroke length - 3.2993353100821
9.52 just seems pretty high for me.
*edit* i just switched out my "advertised duration" from the dynamic stroke calculater from using the 235/235@ .050 to using the 285/285 @ .006 and i came up with 8.00 for dynamic, does that sound about right?
Last edited by Shawn MacAnanny; 07-13-2008 at 09:50 AM.
07-13-2008, 09:50 AM
#2
Yes, you need to input the duration at .006" for the DCR calculator to work. 7.811:1 sounds about right. 
__________________
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
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
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
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
07-13-2008, 09:57 AM
#3
Yeah i rechecked the calculater when i tried it again and had realzed i had left my other cam specs (HPE S cam) in there for LSA 115+5 and that took me down to 7.811. I re did it with the correct 110+4 and came up with 8.0 so that seems about right. Thanks Pat! BTW the cam im running is one you spec'd for a board members stroker haha. When i saw it for sale i decided i must have it just to see how it run in a carbed 346
