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Travis Miller · 05-06-2010, 10:42 PM

To Bruce, Alan, and anyone else concerned with this rocker arm discussion,

I got in this discussion when the statement was incorrectly made that any rocker arm ratio could be used. That led people to believe that it was legal to use 1.6 or 1.7 rockers when the specs call for 1.5 rockers. Then it expanded to therotical measurement using off the car tools. We could not care less what the rocker arm ratio is when it is laying on the workbench. We are concerned with the "as run on the engine ratio". That ratio is figured by taking the lift at the retainer and the lift at the lifter then doing the math. As long as that ratio does not exceed the spec in the Engine Blueprint Specification for an OEM or accepted replacement rocker arm, it will pass.

We know that the ratio of stamped steel rocker arms can vary, usually to the short side. That is why the spec given is the max allowed. However an OEM rocker arm that the factory says is 1.5 is not going to figure out to be 1.6 or 1.7. That ratio comes from using the wrong rocker arm. If the spec says that the ratio is 1.5, then that is the max the ratio can be. If anyone wants to play with having a cam ground to make up for factory shortcomings, fine. Just be sure you meet the lift specs at the valve retainer and you do not exceed the rocker arm ratio specs. If you do happen to run across a rocker that exceeds the spec for the ratio, then its simple...do not use it.

Now you know how we check ratio....lift at the valve retainer and lift at the lifter, then do the math.

Travis

(Disclaimer: Opinions expressed by me on this forum are exactly that, my opinions.)

05-06-2010, 10:42 PM	#22
Travis Miller Member Join Date: Jun 2007 Posts: 478 Likes: 1 Liked 276 Times in 27 Posts	Re: Rocker Arms To Bruce, Alan, and anyone else concerned with this rocker arm discussion, I got in this discussion when the statement was incorrectly made that any rocker arm ratio could be used. That led people to believe that it was legal to use 1.6 or 1.7 rockers when the specs call for 1.5 rockers. Then it expanded to therotical measurement using off the car tools. We could not care less what the rocker arm ratio is when it is laying on the workbench. We are concerned with the "as run on the engine ratio". That ratio is figured by taking the lift at the retainer and the lift at the lifter then doing the math. As long as that ratio does not exceed the spec in the Engine Blueprint Specification for an OEM or accepted replacement rocker arm, it will pass. We know that the ratio of stamped steel rocker arms can vary, usually to the short side. That is why the spec given is the max allowed. However an OEM rocker arm that the factory says is 1.5 is not going to figure out to be 1.6 or 1.7. That ratio comes from using the wrong rocker arm. If the spec says that the ratio is 1.5, then that is the max the ratio can be. If anyone wants to play with having a cam ground to make up for factory shortcomings, fine. Just be sure you meet the lift specs at the valve retainer and you do not exceed the rocker arm ratio specs. If you do happen to run across a rocker that exceeds the spec for the ratio, then its simple...do not use it. Now you know how we check ratio....lift at the valve retainer and lift at the lifter, then do the math. Travis (Disclaimer: Opinions expressed by me on this forum are exactly that, my opinions.)