Cam Timing Question
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Burning Brakes
Joined: Mar 2010
Posts: 803
Likes: 4
From: Christchurch, New Zealand
And this is why I ask. You guys really know your stuff!
Haven't seen any moa for a while. My ancestors ate them all when they weren't eating each other. And my wife will tell you I haven't seen a mower for a while either with all the Vette stuff going on!
Cheers
Grant
Haven't seen any moa for a while. My ancestors ate them all when they weren't eating each other. And my wife will tell you I haven't seen a mower for a while either with all the Vette stuff going on!
Cheers
Grant
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Kelly's comprehensive calculator is quite well done, and IMHO the accompanying primer on theoretical DCR (tDCR) based on IVC is a worthwhile read...
That said, before anyone jumps to the conclusion that tDCR (as so calculated) is the holy grail of engine design, it's worth noting that actual DCR in a working engine = CR x VE% at a given RPM. And, since it's possible for two engines with vastly different CR's and cams (as well as other variables) to yield the same tDCR, I'd suggest valuing tDCR on somewhat of a sliding scale; rule of thumb being to leave more margin for max cylinder pressures the wilder is the build in question. My $.02
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That said, before anyone jumps to the conclusion that tDCR (as so calculated) is the holy grail of engine design, it's worth noting that actual DCR in a working engine = CR x VE% at a given RPM. And, since it's possible for two engines with vastly different CR's and cams (as well as other variables) to yield the same tDCR, I'd suggest valuing tDCR on somewhat of a sliding scale; rule of thumb being to leave more margin for max cylinder pressures the wilder is the build in question. My $.02
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Last edited by TheSkunkWorks; Jan 24, 2012 at 10:38 PM.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
