Longer push rods ?

Alan Roehrich · 09-01-2011, 09:59 AM

You may or may not see a gain. It depends on what it does to the over all lift curve.

A rocker arm, especially a stud mounted rocker arm, is a variable ratio lever. It will never be the same ratio throughout the lift curve. Now, by getting the lift you're supposed to get, you are correcting the ratio and the geometry at maximum lift, and losing the least amount of motion there. You may have decreased the ratio elsewhere in the lift curve, for example, down around 0.100" to 0.200" lift.

The only way to know for sure exactly what you've done is to plot the curve on a graph for each pushrod length. Then try both, at the track, on the dyno, or both.

09-01-2011, 09:59 AM	#2
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,137 Likes: 1,617 Liked 1,927 Times in 433 Posts	Re: Longer push rods ? You may or may not see a gain. It depends on what it does to the over all lift curve. A rocker arm, especially a stud mounted rocker arm, is a variable ratio lever. It will never be the same ratio throughout the lift curve. Now, by getting the lift you're supposed to get, you are correcting the ratio and the geometry at maximum lift, and losing the least amount of motion there. You may have decreased the ratio elsewhere in the lift curve, for example, down around 0.100" to 0.200" lift. The only way to know for sure exactly what you've done is to plot the curve on a graph for each pushrod length. Then try both, at the track, on the dyno, or both. __________________ Alan Roehrich 212A G/S