ok so im hoping this is simplier than what i originally thought. upon further inspection of the rockers and the poly locks i notice there is a nice wear mark on the body of each rocker slot and a matching mark on the shoulder of each poly lock. this leads me to believe that the pushrods were too long and causing it to bind up. im guessing the lifters werent all the way pumped up when i was adjusting and it masked the problem. on a good note my machinist/friend is covering the cost of the new studs, shorter push rods and intake gaskets. im hoping its this simple as it seems to make sense. if it was piston to valve clearance i would have thought you could here the valves smacking the pistons.
valvetrain carnage
- Thread starter mebe007
- Start date
Determine the length of your push rod that gives you the correct valve train geometry - its probably the most over looked in a build. Comps cams has instructions in thier learning center. I would have a hard time trusting those rockers.
Personal choice and what you are trying to accomplish. SBC cams are usually designed around a 1.55 rocker and I have used nothing but and bought my cams accordingly. The 1.6 will of couse give you more lift - you will loose some bottom and pick up on the top.
Of any remaining good parts you have left from the valvetrain assemble intake and exhaust on ONE cylinder, adjust the valves properly (1/2 turn down from zero lash or whatever you prefer to use) and watch the rocker movement through the lift cycle. Just looking at the location of the poly-lock in the rocker arm slot can tell you a lot. If it's comeing close to the end of the slot in either the valve-closed or full-lift positions that's a dead give-away that the sticks are the wrong length. There should be plenty of clearance on both ends of the rocker slot.
It may well be as you say that the pushrods are too long. But sticks that are too short can cause horrendous problems as well.
I'm only mentioning this because I see contact between the rocker body and the rocker stud in your pictures. And clear evidence that the rocker tip has walked off the side of the valve stem. I'm not saying nothin' here. I'm just saying that something sniffs a little weird. Check and double check. Then decide on the pushrods.
It may well be as you say that the pushrods are too long. But sticks that are too short can cause horrendous problems as well.
I'm only mentioning this because I see contact between the rocker body and the rocker stud in your pictures. And clear evidence that the rocker tip has walked off the side of the valve stem. I'm not saying nothin' here. I'm just saying that something sniffs a little weird. Check and double check. Then decide on the pushrods.
What could cause the walk besides a bent/ bending pushrod causing excesdive play in the rocker. I have gudeplates instaled as wel just like i should
