I just installed a set of Scorpion 1.6 rockers on new aluminum heads with rod guides. I did the whole setup with 90 degree turns following the firing order, taking out the lash and then 3/4 turns and locking the Poly's. I then cranked the engine over by hand a few times and noticed the pushrods jumping out of the center of the lifter bowl over to the side. They don't come out of the lifter but they move right over to the edge. Once they get back on to the compression stroke, they seem to center. I tried installing them dry, then pumping them up and it's doing the same thing. These are also brand new Johnson lifters. Any of you ever see this happen? I don't want to try starting it like that. I'm worried they may kick right out under the force.

 

Not sure what's going on with that but let me take a WAG

It's interesting that it's happening while turning the engine over by hand But good you caught it

For the pushrod to leave the cup you need slack or loss of control. Now IF the lifters are sticking some, then they compress when lifting/opening the valves and on the downramp of the cam lobe, for some reason the lifter travels a bit faster than the pushrod??? And IF the guideplates are a bit tight, so the pushrod drags a bit allowing them to separate from the collapsed lifter opening up some space before the lifters unstick.... idk you'd need a couple things to go wrong for this senario but w/e seen some messed up stuff before.


Did you soak the lifters?
What size pushrods, brand?
What brand guideplates?
Are the guideplates tight with slight angle?
Did you use an excessive amount of assembly lube?

I know the Comp Cam & Dart(same manufacturer as Comp) guideplates are tighter on some brands of the pushrods I've used, so I won't use them. I also know some overseas guideplates are way too tight or the groove is not deep enough, had a friend grind his procomp ones to make them work/fit the pushrods. Told him he most likely went thru the surface hardening, gave him some used ones I had n advised him to toss those.

1.6 rockers move the cup I think towards the stud(just looked & compared a 1.5 to 1.6 of same brand the other day) so maybe your pushrods are bottoming out in the guideplate groove???

 

It's definitely the guide plate. I took them out and tried and there was no issue. They're not deep enough and the rod is basically trying to bend around the back of the slot.

 

I took the Dremel to the plate and zinged the gap back about.025. Seems to be ok now. Hand cranked it through a few revolutions and they appear to be tracking just fine.

 

Good thing you found that before starting the engine!

 

Yeah no kidding. That would have sounded like someone kicked the barbecue down the stairs.