Editing Dynamic compression ratio
Line 1: | Line 1: | ||
+ | ==Beyond DCR== | ||
+ | There is a limit to what DCR can do. Other concepts have been developed that take this a step (or several steps) further than what DCR is able to accomplish. | ||
+ | *[http://victorylibrary.com/mopar/cam-tech-c.htm#factor Cam Timing vs. Compression Analysis] is an "advanced" formula for looking at the relationship of SCR vs. DCR. In the text the author uses "'''''supra'''''" a lot, it basically means "more info above". | ||
+ | *[http://horsepowerchain.com/ The Horsepower Chain] attempts to put things into a mathematical prospective, and breaks the 4-stroke engine's cycles into 7 distinct segments. | ||
+ | |||
==Online calculators== | ==Online calculators== | ||
===Static CR=== | ===Static CR=== | ||
Line 4: | Line 9: | ||
===Dynamic CR=== | ===Dynamic CR=== | ||
− | |||
− | |||
*[http://www.wallaceracing.com/dynamic-cr.php Wallace Racing DCR calculator] | *[http://www.wallaceracing.com/dynamic-cr.php Wallace Racing DCR calculator] | ||
+ | *[http://www.empirenet.com/pkelley2/DynamicCR.html Kelly DCR calculator] | ||
+ | *[http://www.kb-silvolite.com/calc.php?action=comp2 KB/Silvolite DCR calculator] | ||
*[http://www.rbracing-rsr.com/comprAdvHD.htm RSR DCR calculator] | *[http://www.rbracing-rsr.com/comprAdvHD.htm RSR DCR calculator] | ||
− | |||
− | {{Note1}}If the intake | + | {{Note1}}If the intake closing (IC) point isn't known, it can be calculated: |
− | # Divide the | + | # Divide the intake duration by 2 |
# Add the results to the lobe separation angle (LSA) | # Add the results to the lobe separation angle (LSA) | ||
# Subtract any ground-in advance | # Subtract any ground-in advance | ||
# Subtract 180 | # Subtract 180 | ||
− | This result does not need to have any amount added | + | This result does not need to have any amount added, like the KB calculator calls for. |
==DCR and pump gasoline== | ==DCR and pump gasoline== | ||
Line 41: | Line 45: | ||
*12.00.......68............8.017........................................................................................................ | *12.00.......68............8.017........................................................................................................ | ||
− | + | ==Disclaimer== | |
− | + | Now, it's unclear where these Keith Black DCR calculator dynamic compression ratio readings are taken; at cranking rpm or at max efficiency rpm. According to the DynoSim software, maximum cylinder pressure is made at or near the torque peak. So, the fact that a motor is not detonating at low rpm does not mean that it will not detonate at, or close to, the torque peak. | |
These numbers may not mean anything at all, but they do illustrate that you cannot just pick a cam out of thin air like a lot of fellows do and expect it to work best for your particular combination. | These numbers may not mean anything at all, but they do illustrate that you cannot just pick a cam out of thin air like a lot of fellows do and expect it to work best for your particular combination. | ||
− | |||
− | |||
− | |||
− | |||
<br><br> | <br><br> | ||
− | |||
{{youcanedit}} | {{youcanedit}} | ||
[[Category:Engine]] | [[Category:Engine]] | ||
[[Category:Cylinder head]] | [[Category:Cylinder head]] |