I've been seeing a ton of T&D and Jesel rockers on E-Bay for various engines and they all spec both the rocker ratio and pivot ratio. I'm too lazy to try and get my head around what the pivot ratio is and what it means. Hopefully someone knowledgeable will pipe up...

 

http://www.yellowbullet.com/forum/sh...d.php?t=442170

 

Thanks, DM. I'm not understanding the ratio part. A ratio is the relationship between two factors. The diagram from the YB post only shows the rocker ratio (Y/X), and while the poster stated that "Y" was the pivot ratio, there is no other factor for a proper ratio to take place...

 

I believe the specifications indicated are (1) the pivot length; and (2) the rocker ratio. There is no "pivot ratio." The ebay listings confuse this by, for example, indicating "1.75 pivot/2.00 ratio" which suggests a "pivot ratio" when actually it means a 1.75 pivot length and a 2.00-to-1.00 rocker ratio.

 

I guess that could be considered a ratio when compared to 1". IE, 1.65 pivot ratio would be 1.65" from the rocker shaft centerline to the roller tip centerline (1.65" : 1.00").