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Old 01-15-2007, 12:28 PM
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ByronRACE ByronRACE is offline
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Join Date: Feb 2002
Location: Gilroy, CA
Cobra Make, Engine: West Coast Cobra w/ Centrifugally Blown Big Block, Pickles, Onions, on a Sesame Seed Bun.
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Default Cam duration

Quote:
Originally Posted by Don
Byron:

Appears the cam is a Crower, not more than a 280 duration and 526 lift , only data available. Within the range for tuning as mentioned earlier to meet the 1.20 CO and 220 HC ?

280 at .050? The industry standard is to measure duration starting at .050" lift. Assuming that's the duration number given, that's a pretty big cam. 526 lift, however seems to suggest it's probably not a .050" number.

So, I'll say it depends.... if it's 280 at .050, I'd say chances are NOT good...that's a pretty racey cam and would have rough idle/cruise characteristics. If it's 280 at .020, that's about a 240 duration cam at .050...and you'll most likely pass assuming the lobe center and overlap is somewhat normal/typical for a cam of that type.

So, I go back to my qualitiative statements about idle lope and rpm to determine how lumpy the cam is.

Here's a table of typical cam types...you can sort-of get a feel for duration and lift numbers as well as seperation by looking at what's been done in the past. Your cam PROBABLY doesn't deviate too far from one of these.

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