Q's about using this DCR calc?
12-10-2006, 08:32 PM
#1
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Q's about using this DCR calc? I just got my camshaft from Thunder Racing, and am trying to use this calculator to figure my Dynamic Compression Ratio with variable head gaskets and chamber volumes.
http://www.kb-silvolite.com/calc.php?action=comp
My IVC event @.050 is 45.1* ABDC, when I use the calc per instruction (using the .050 value and adding 15*) I get what I believe to be unusually high DCR's. For example, using a factory 243 head (64cc) and factory .060 MLS head gaskets, I get a SCR of 10.544 (which seems to be accurate), but the DCR comes out to 8.692 which is getting close to the upper limit for use with pump 93 octane gas. This can't be right can it? Factory LS6's don't have DCR's that high, do they? My 45.1* IVC (@.050) is only 2* later than the factory cam, and I shouldn't think the factory DCR would be that high.
Logic tells me to use the IVC event number @ .006 (just the VE number - no adding 15* either!), which is a lot closer to when the intake valve actually closes (which is what DCR is based upon). Doing so, I get a DCR of 7.909 for the factory set up. Isn't this closer to what a set of factory 243's on a factory head gasket should show?
I've tried to use the DCR calculators by Piano Prodigy and J-Rod, but they are both .xls spreadsheets which I don't have the software to support on the home computer. Anybody have any other DCR calculators out there?
Ideally, I'd like to run a 62cc chambered head on a .040 head gasket with my 45.1*IVC @ .050 cam in an otherwise stock '04 LS1 and be able to keep the DCR's under 8.8 (for use with 93 octane and a 160* T-Stat).
Any help / advice using this or any other DCR calculator would be appreciated!
Good Day!
http://www.kb-silvolite.com/calc.php?action=comp
My IVC event @.050 is 45.1* ABDC, when I use the calc per instruction (using the .050 value and adding 15*) I get what I believe to be unusually high DCR's. For example, using a factory 243 head (64cc) and factory .060 MLS head gaskets, I get a SCR of 10.544 (which seems to be accurate), but the DCR comes out to 8.692 which is getting close to the upper limit for use with pump 93 octane gas. This can't be right can it? Factory LS6's don't have DCR's that high, do they? My 45.1* IVC (@.050) is only 2* later than the factory cam, and I shouldn't think the factory DCR would be that high.
Logic tells me to use the IVC event number @ .006 (just the VE number - no adding 15* either!), which is a lot closer to when the intake valve actually closes (which is what DCR is based upon). Doing so, I get a DCR of 7.909 for the factory set up. Isn't this closer to what a set of factory 243's on a factory head gasket should show?
I've tried to use the DCR calculators by Piano Prodigy and J-Rod, but they are both .xls spreadsheets which I don't have the software to support on the home computer. Anybody have any other DCR calculators out there?
Ideally, I'd like to run a 62cc chambered head on a .040 head gasket with my 45.1*IVC @ .050 cam in an otherwise stock '04 LS1 and be able to keep the DCR's under 8.8 (for use with 93 octane and a 160* T-Stat).
Any help / advice using this or any other DCR calculator would be appreciated!
Good Day!
12-11-2006, 07:42 AM
#4
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Thanks guys. I'll use the .006 number and be confident with the calcs. I guess I was just double checking my logic, as I don't believe I'm trying to run a radical setup, but I was getting some outrageous DCR's in the mid 9's using their instructions.
Thanks again...
Thanks again...
12-11-2006, 08:00 AM
#5
Can someone post in the sticky exactly what the stock measurements are for a stock ls1.
I always forget what the stock stroke is as well as rod length. I know the stock bore is 3.898", but forget what the stock stroke is. Is it 3.626"? What's the rod length?
I always forget what the stock stroke is as well as rod length. I know the stock bore is 3.898", but forget what the stock stroke is. Is it 3.626"? What's the rod length?
