I have a comp cams hyd. roller. Today while driving, the engine started misssing, so I pulled off the drivers side valve cover and cylinder 3 had both pushrods sticking through the rocker arms!!! All other rocker arms are fine. I am wanting to know if this has happened to anyone else? I am going to order a set of roller rockers tomorrow.
Push rods are sticking through the rocker arm
- Thread starter CS99
- Start date
Rodney87GN
Well-Known Member
- Joined
- Feb 1, 2004
Hmm, after seeing that I'm thinking of going with roller rockers after all. I'm getting all the parts for my motor rebuild which includes a roller cam....
I was gonna go with HD shafts with new stock rocker arms to save a little money but I might reconsider.
I was gonna go with HD shafts with new stock rocker arms to save a little money but I might reconsider.
jhanson1750
just a 10th quicker
- Joined
- Apr 24, 2005
I've seen this with high spring pressures and low oil flow/pressure. Causes the pushrods to "dig" into the rocker arm. Good luck with the car Jon Hanson
turbofabricator
Well-Known Member
- Joined
- Mar 7, 2004
I smell detonation. Usually, it just bends the push rod, though. I have not seen that with a hyd. roller and stock rockers. Did you pre-lube the push rod cup prior to install? Might have failed at start-up. Lube EVERY piece with good assy. lube on installation.
TT/Ameasap
The White Blur
- Joined
- Jan 31, 2002
Thats what im thinking.
Me too. Geometry problems will do this every time if its off enough. Ive seen it do it to rollers too. Especially on chevys with too long of a pushrod.
johnnyttype
Active Member
- Joined
- Apr 18, 2007
can detonation cause both #3's to be crippled? just wonderin, i do find it strange that it was common to a cylinder.
CS99, atleast u know u have some strong pushrods!!! my friends 350 put a pushrod through a rocker but his pushrod was shaped more like a pretzel!
Red Regal T
Senior Member
- Joined
- May 24, 2001
Had this happen on my dark red T a few months ago. Only one pushrod. The car is stock, original unopened. I think it's caused by an inferior, poorly casted, rocker arm and/or old age. Lasted 20 years, though. 
Weak casting can cause this to occur, i know of a few low mileage GNs cranks snapping in two from normal driving. Guess lack of oil and tight clearences can cause this. An earlier post of a Block missing a large section of the lifter valley was missing. Also engine blocks breaking in two from 20-25# of boost sometimes these things happen...
turbofabricator
Well-Known Member
- Joined
- Mar 7, 2004
I've seen BOTH push rods on #3 cyl. bent into an "S" shape. He did detonate it REAL bad, though. The piston alspo had some edges missing, and a crack in the main webbing, and two main caps broken. The push rods were the least of his worries. Running your alcohol tank dry is a VERY bad thing.
The piston alspo had some edges missing, and a crack in the main webbing, and two main caps broken. The push rods were the least of his worries. Running your alcohol tank dry is a VERY bad thing.That is severe damage, did the timing chain break by chance? Almost sounds like the piston contacted the both valves. How many pounds of boost were on the motor? Sorry to hear this
The amount of boost is irrelevant. It detonated really bad. It could happen at 19 psi. Id bet the connecting rods were tweaked also and the rod bearing shells pounded out. Fwiw the stock rocker arms are stamped steel and are actually fairly strong just because they are stamped. There has to be wear there before the pushrod will go through the arm. The stock rocker shafts are weaker than the arms and fasteners that hold them in place.
