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FE Power Forums => FE Technical Forum => Topic started by: fryedaddy on August 26, 2017, 10:55:02 AM

Title: non adjustable to adjustable rockers lift changes
Post by: fryedaddy on August 26, 2017, 10:55:02 AM

does it change the lift of a cam when you go up on the rocker ratios,if so how much?

Title: Re: non adjustable to adjustable rockers lift changes
Post by: My427stang on August 26, 2017, 11:28:40 AM

1.73% difference not assuming differences in pushrod angle, etc.  That is an ironic number given the rocker ratio LOL

Using lobe values, if you have a .330 lift lobe, .330*1.73 = .571, with a 1.76 rocker, it'd be .581

Using percentage difference, .571 * 1.0173 = .581 as well

Keep in mind that affects the entire curve, so it functionally adds duration at the valve too.  The valve will be open the same amount at .050 with hyd rockers as it will be at .0491 lobe lift with 1.76 adjustables.  Not significant IMHO, but technically it does hang the valve open slight longer

Title: Re: non adjustable to adjustable rockers lift changes
Post by: fryedaddy on August 26, 2017, 05:23:43 PM

thanks for the info,i dont know if you can hear or feel the differences but after going to adj. rockers it seems like my engine dont smooth out till a little higher rpm.if that makes sense.