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Old 05-26-2008, 12:46 PM
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8/8 split rocker ratios

I have a high energy 268H in a sbc with 882 heads home ported with 1.94I. It is a split profile cam and with my setup I feel that I could benefit from running a 1.6 rocker on the exhaust. That would make it 218/218 .454/.483 versus 218/218 .454/.454. This should help with exhaust gas scavenging. Has anyone ever tried this?

-Ray

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Old 05-26-2008, 01:21 PM
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Yes I have tried this but after checking the rocker to valve geometry, I had to change the push rods to shorter ones on the exhaust to get it back in alignment in the center of the valve. It was more hassle than it was worth for the net gain, and did not seem to make any difference. I wound up ordering a different cam profile for the next race.
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Old 05-26-2008, 02:55 PM
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In most comparisons I've seen, the 1.6 rockers look like much ado about nothing.
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Old 05-26-2008, 03:13 PM
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You'd probabily find more of a power gain by using the 1.6 rockers on the intake side. The exhaust responds more to valve timing duration changes than to lift changes.
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Old 05-26-2008, 06:35 PM
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Quote:
Originally Posted by F-BIRD'88
You'd probabily find more of a power gain by using the 1.6 rockers on the intake side. The exhaust responds more to valve timing duration changes than to lift changes.
good advise, right on the money.
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