Question on larger ratio rockers?
10-06-2002, 10:19 AM
#1
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Question on larger ratio rockers? Crane sells 1.8 rockers and SLP sells 1.85 rockers. Does this up ration effect duration and lift or just one or the other. What is the calculation to determine what gain on lift and or duration you are getting.
Also, is it only safe to up the ratio on the rockers if your using the stock cam? I have the old Lunati T1 in my car now. Would it be safe to go with larger rockers?
The specs on the T1 if you don't know are 221/221 dur @.050 558/558 lift on a 112 deg LSA.
Any help is appreciated.
Andy <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Also, is it only safe to up the ratio on the rockers if your using the stock cam? I have the old Lunati T1 in my car now. Would it be safe to go with larger rockers?
The specs on the T1 if you don't know are 221/221 dur @.050 558/558 lift on a 112 deg LSA.
Any help is appreciated.
Andy <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
10-09-2002, 08:17 AM
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Re: Question on larger ratio rockers? Here is my remedial math... 1.8 rocker=.591 lift, 1.85 rocker.607 lift. Hope that helps <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
10-09-2002, 01:25 PM
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Re: Question on larger ratio rockers? Jesel makes 1.75, 1.80 & 1.85 rockers for these motors as well. Since the rocker multiplies the lobe lift, there is a slight increase in duration when measured as valve lift. The degree which duration will change is a function of the lobe profile. More aggresive lobes will have less duration change at the valve than milder ramp profiles.