Re: Rocker arm ratios
[Re: littlejohn44]
#2530793
08/03/18 01:06 AM
08/03/18 01:06 AM
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Joined: Aug 2003
Posts: 43,174 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,174
Bend,OR USA
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I have a set of Eddy Victor heads with Hughes offset intake rockers and crane gold exhausts. I measured at the retainer with a dial indicator on the cranes and i am getting .020 more lift than what i should be getting . Lobe lift is .410"/.414" using 1.6 rockers should be .656/.662 . I am getting .682 on the exhaust and .632 on intake. My lobes measure out with +/- .001-.002 . The cranes are stamped 1.6 but this is closer to 1.65? The hughes are closer to 1.55. I figured it might be my accuracy in measuring but they are pretty even across both sides? And your question is?
Last edited by Cab_Burge; 08/03/18 01:06 AM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Rocker arm ratios
[Re: littlejohn44]
#2530854
08/03/18 10:33 AM
08/03/18 10:33 AM
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Joined: Jan 2003
Posts: 14,498 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,498
So. Burlington, Vt.
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My one experience with Hughes rockers, and it was the older version without the slot down the middle....... Std offset BB rockers, EZ heads, 1.6 ratio.....just under 1.6 with a checking spring, about 1.51-1.52 with 600lbs of spring load.
My experience has been that Cranes are usually about .05 higher than advertised when measured with a checking spring.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Rocker arm ratios
[Re: fast68plymouth]
#2531029
08/03/18 03:53 PM
08/03/18 03:53 PM
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Joined: Dec 2014
Posts: 121 ky, usa
littlejohn44
OP
member
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OP
member
Joined: Dec 2014
Posts: 121
ky, usa
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My one experience with Hughes rockers, and it was the older version without the slot down the middle....... Std offset BB rockers, EZ heads, 1.6 ratio.....just under 1.6 with a checking spring, about 1.51-1.52 with 600lbs of spring load.
My experience has been that Cranes are usually about .05 higher than advertised when measured with a checking spring. That's about what I'm getting. I am not using checking springs. I have checked them 10 times each thinking I was crazy. I am using the old style Hughes also would have figured they would be s little more accurate since not produced on a scale as large as cranes.
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Re: Rocker arm ratios
[Re: littlejohn44]
#2531046
08/03/18 04:19 PM
08/03/18 04:19 PM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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The rocker ratio will vary slightly over the length of travel. The stated ratio may have been with a specific lobe height.
Boffin Emeritus
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Re: Rocker arm ratios
[Re: littlejohn44]
#2531536
08/04/18 04:12 PM
08/04/18 04:12 PM
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Joined: Aug 2003
Posts: 43,174 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,174
Bend,OR USA
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I've check a bunch of different rocker arms for ratio at the retainers, even the good ones will vary some in the same set I've seen T&D single shaft sets vary .030 at the retainers, same on some of the older Harland Sharp sets. The older ductile iron sets sold by all of the cam company are horrible also, same on the extruded aluminum sets
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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