viewtopic.php?f=52&t=82
http://www.dapa.org/jhpages/pontiac-cams-2.htm
http://www.compcams.com/Community/Artic ... 2026144213
on the better 23 degree SMALL BLOCK AFTERMARKET HEADS THERE'S ABOUT 5.5 INCHES OF INTAKE PORT LENGTH ON AVERAGE FROM INTAKE GASKET TO THE BACK OF THE INTAKE VALVE AT THE FAR EDGE
quote
"GENERAL RULES FOR CAM SELECTION
1.
Use a fairly tight lobe separation cam and shift at lower RPM with a heavy vehicle running a high (2 series) rear axle.
2.
If you want a wide RPM range with a decent idle, use a wider lobe separation cam.
3.
Disregarding the adverse effect on idle quality and off idle power, a wider duration cam with it's higher RPM range allows you to run tighter lobe separation cams.
4.
Always try different maximum shift points at the strip to find which produces the best ET with your combination. Tighter lobe cams will generally provide better ETs if shifted earlier, in comparison to wider lobe cams.
5.
Both the duration and lobe separation should match the RPM range you plan to load the engine.
6.
True leakdown lifters (such as Rhoads) extends the power range down to a lower RPM, and allows a higher RPM cam to be used in a driveable vehicle.
7.
If running nitrous, use wider lobe separation cams having additional 10 degrees or more exhaust duration than intake duration.
8.
With radical duration race cams (260+), lobe separation may have to be widened due to the negative effects of increased overlap. "
MORE VERY USEFUL INFO, in the links
http://www.popularhotrodding.com/tech/0 ... index.html
http://www.hotrod.com/techarticles/113_ ... ology.html
http://www.enginebuildermag.com/Article ... teria.aspx
viewtopic.php?f=52&t=181
viewtopic.php?f=52&t=528
viewtopic.php?f=52&t=904
http://books.google.com/books?id=1ypb-B ... q=&f=false
http://69.20.53.62/faq_valvetrain.php
http://www.shenyu-sjz.com/parts/camshaf ... mshaft.htm
http://www3.sympatico.ca/david.crooks/cam.PDF
http://www.dapa.org/jhpages/pontiac-cams-2.htm
http://www.compcams.com/Community/Artic ... 2026144213
on the better 23 degree SMALL BLOCK AFTERMARKET HEADS THERE'S ABOUT 5.5 INCHES OF INTAKE PORT LENGTH ON AVERAGE FROM INTAKE GASKET TO THE BACK OF THE INTAKE VALVE AT THE FAR EDGE
quote
"GENERAL RULES FOR CAM SELECTION
1.
Use a fairly tight lobe separation cam and shift at lower RPM with a heavy vehicle running a high (2 series) rear axle.
2.
If you want a wide RPM range with a decent idle, use a wider lobe separation cam.
3.
Disregarding the adverse effect on idle quality and off idle power, a wider duration cam with it's higher RPM range allows you to run tighter lobe separation cams.
4.
Always try different maximum shift points at the strip to find which produces the best ET with your combination. Tighter lobe cams will generally provide better ETs if shifted earlier, in comparison to wider lobe cams.
5.
Both the duration and lobe separation should match the RPM range you plan to load the engine.
6.
True leakdown lifters (such as Rhoads) extends the power range down to a lower RPM, and allows a higher RPM cam to be used in a driveable vehicle.
7.
If running nitrous, use wider lobe separation cams having additional 10 degrees or more exhaust duration than intake duration.
8.
With radical duration race cams (260+), lobe separation may have to be widened due to the negative effects of increased overlap. "
MORE VERY USEFUL INFO, in the links
http://www.popularhotrodding.com/tech/0 ... index.html
http://www.hotrod.com/techarticles/113_ ... ology.html
http://www.enginebuildermag.com/Article ... teria.aspx
viewtopic.php?f=52&t=181
viewtopic.php?f=52&t=528
viewtopic.php?f=52&t=904
http://books.google.com/books?id=1ypb-B ... q=&f=false
http://69.20.53.62/faq_valvetrain.php
http://www.shenyu-sjz.com/parts/camshaf ... mshaft.htm
http://www3.sympatico.ca/david.crooks/cam.PDF