Help with pushrods

[mrfomoco]

I recently installed Trick Flow Twisted Wedge heads on my 351w. I read through the instructions and saw that the recommended pushrod length is 8.05 for a 351w with a hydraulic roller, so these are the ones i ordered. I've been playing with the rocker arm adjustment which are 1.6 roller rockers from Trick Flow as well and whenever the lifter is UP i can get zero lash but whenever I turn the motor over and the lifter goes down it becomes completely loose. I'm thinking the pushrods are too short, any help would be appreciated.

 

[ShannonW]

Heres a webpage that explains how to determine the correct pushrod length http://www.compcams.com/Technical/Products/Pushrods/ .

Hope it helps you out.

 

[D.Hearne]

First of all, you don't adjust the rockers when the lifter is at it's highest point of lift. You adjust them when the lifter is on the base circle of the cam lobe.( valve closed) Best way to do this, is to adjust each set ( intake & exhaust) when the cylinder they're on is at TDC on the firing stroke. Then adjust each til the pushrod stops spinning, then turn the adjuster nut 1/2 to 3/4 turn and lock them in place.

 

[D.Hearne]

Alos you need to know if the roller cam you're using is a reduced base circle design, or a stock type high performance hyd roller cam ( such as a Ford Racing B, E, F,X or Z303 cam)

 

[mrfomoco]

It is a comp cams retro-fit roller cam. Thanks for the info I believe the pushrods are much too short as when the valve is closed I cannot get the rocker tight enough to even touch the pushrod. Hmph.

 

[D.Hearne]

If it's a retro-fit, then it's a reduced base circle design, and thus requires longer pushrods.