What type cam with how much lift and and what valve springs are you using ? What are your valve spring installed height and coil bind numbers? The answer to your problem may lie there. IE if your installed height is ,say 1.840" and your springs coil bind at 1.300" your spring travel is .540".That means you cannot run a cam with more than .480" lift and maintain any safety margin at all.You also need to know how much valve travel you have.That is simply how far the valve\spring\retainer can move before the retainer hits the top of the guide\ guide seal.We need more information.
What about valve spring rate, too heavy a spring, incorrect pushrod(s) or length and/or geometry. As stated tell us about what you currently have installed; single or double springs, cam type and specifications, OEM rocker shaft assembly or aftermarket, rocker arm ratio (Adjustable or not) etc. Not sure if the piston to valve clearance is relevant? When specifics are known someone more knowledgeable than me with more experience will hopefully chime in. Having had a FE I know that I had no issues with the stock shaft rocker assemblies and mild street cam. I just had to shim the stands. Yours may require shimming or milling? The rocker arm may move with a stud system however not with a shaft system unless worn. OEM installed spring height I believe was 1.82". If you are using a higher lift cam the rocker-shaft stand height must be shimmed to maintain the correct rocker geometry.
My only comment is I've never seen a broken PR before, lotta bent ones, but never a broken one, well, other than some import ones with the balls broken off.
what's happening is the cup breaks at the end of the pushrod. thanks for help . I will do some more investigation into the valve springs Sent from my SM-G920V using The H.A.M.B. mobile app
Have the heads been milled? Solid or hydraulic cam? Sent from my SM-G550T using The H.A.M.B. mobile app
hydraulic not sure if the heads were milled bought a long block just rebuild Sent from my SM-G920V using The H.A.M.B. mobile app
So you dont know what cam is in the engine? I know its a pain but if you pull the intake you can measure the lifter travel on one intake and one exhaust lifter from closed to open.This will give you cam lift.You can then add your rocker arm ratio-iirc 1.73 non adjustable and 1.76 adjustable and that will give you valve lift.IE .100" cam lift would give you .176" valve lift.Then determine valve spring coil bind height and valve spring installed height .IE-installed height= 1.820" coil bind =1.200 gives you a spring travel of .620".Subtract .080" and the max lift you can run with those springs is .540 " .These numbers are for illustration only. The .080" is because you NEVER run a valve spring closer than .o60" to coil bind and .080" is safer.This is just how I do this, other folks may have different methods.
The Jalopy Journal
