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Old 03-11-2008, 10:33 AM
Rosco Rosco is offline
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Join Date: Dec 2006
Location: Northwood, NH
Cobra Make, Engine: Unique
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Quote:
Originally Posted by Barry_R View Post
I've only seen really high RPM out of hydraulic rollers in cars that were required to run them by the class rules. They "cheat" them into acting solid by nearly bottoming out the innards with the adjusters. They always seem to poop out on me around 6200 when run normally. But thats where they belong anyhow...

That dyno sheet looks like it had a safe and honest pull on it. I am pretty confident that you could wring more bragging numbers out of it with a leaner mixture - 12.0 coupled with BSFC around .5 shows it pretty safely rich. A bigger carb would also help with the glory part of the pull. I recently tried a 445 incher that made 455 on a 750 and 485 with an 850 - no other changes. Now - put that big carb and lean mixture on your motor and you'll have higher peaks but weaker throttle response, and a higher risk as far as fuel toreance.

Sounds like a nice engine to me....

Can you explain the A/F Ratio and what is optimal in a dyno "pull". I've seen several dyno sheets with different A/F Ratios and am confused...

Does an A/F Ratio of >13 or 14 mean to lean and not a realistic ratio or conversely, <10 A/F mean too rich and perhaps leaving power on the table?

Thanks to all,

R
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