Roller Cam People With Lifter Problems and/or Broken Rocker Arms

[HellOnWheels]

What type of problems have you had and what was done to remedy the problem?

I had a few lifters that did not feel right even after extensive cleaning and now I have a few push rods that have popped out of the adjusting screw on the adjustable roller rockers causing some problems.

Everything was fit with the engine on the stand and the intake off the engine so finding a perfect zero lash was very easy, went 3/4 turn past zero lash. The geometry looks perfect and the witness marks of the roller tip on the valve stem splits the center line on the tip of the valve stem perfectly. Not even close to coil bind on the Beehive springs.

The lifters are now pumped up firm and stay pumped up even days after being removed from the engine. I have always been able to feel, with my hand, some movement in a hydraulic lifter by the time the engine has cooled off but these stay pumped up super firm.

What Is Going On Here? What would cause the push rod to chew into the edge of the adjusting screw? It seems like the only thing that could do it would be excessive space between the push rod and the adjusting screw and the only thing that could cause that is not enough pre-load and 3/4 past zero lash should be plenty, or the lifters either got stuck or did not pump up.

Any Ideas?

TIA

Did you do the modifications to the rocker shaft mounting towers?
I'm running a 224/224 hydraulic roller with the HS 1.65 rockers. Push rods are BB Chevy intakes.

 

[Blown&Injected]

Lee
Yes, I pulled all the lifters and all the cups were up tight to the snap rings. In fact it was so tight even after a few days I could not move the cup in the lifter - never known a lifter to keep pumped up so hard for so long.

Scott
Very interesting question. I casually ran the numbers and since it was in the clear I moved on. I have revisited the issue, see post above for the numbers, and have a fair amount of extra room: .177". The bottom of the coils do seem to close in faster and closer than the upper coils but who knows if they need to be under a certain spec - I have always believed it is important to be about .060 over coil bind and then don't worry about it. i will do some asking around.

HOW
I am using stock iron heads and I did a nice job of clearancing the rocker arms using a mini belt sander - like an air dyna file tool. Thanks for considering this issue, it is a good question and I did not mention any work in that potential problem area.

 

[Blown&Injected]

should be getting the parts back soon, maybe today.

I can't wait to check the feel of the lifters - I sent all the parts the H/S for inspection.

I am thinking that some of the lifters got stuck down - just seems like everything else was right.

 

[Lee Thompson]

Good old Comp hyd. rollers

I have 3 sets (6 lifters ) in the cabinet that are as useless as a screen door on a submarine.

 

[Lee Thompson]

by chance

Were the problem pushrods all on the drivers side?
Did you do anything to restrict the oil to the drivers side galley?
Did you over rev the eng?

 

[Blown&Injected]

4 total:
3 0n the drivers side and 1 on the passenger side - some Intake and some Exhaust.

This engine has not seen more than about 4,100 RPM's.

I had been driving for about 15 minutes, parked for about 15 minutes and then about 2 minutes into the extremely easy drive, about 1/10th throttle; 1,2,3,4th then lock up, kept it at about 50. Just enough gas to get it to OD + Lock-Up.

Then about 60 seconds of tapping then quiet but running like it is out of gas. i then noticed the vacuum gauge bouncing and knew it was not a good thing.



Thanks for all the thought going into this.

 

[Larry Clontz]

Hey Lee, Need some advise on a camshaft. I am mikes friend that came to your house last month. Is there a number that I can reach you?

 

[DonnieShort]

4 total:
3 0n the drivers side and 1 on the passenger side - some Intake and some Exhaust.

This engine has not seen more than about 4,100 RPM's.

I had been driving for about 15 minutes, parked for about 15 minutes and then about 2 minutes into the extremely easy drive, about 1/10th throttle; 1,2,3,4th then lock up, kept it at about 50. Just enough gas to get it to OD + Lock-Up.

Then about 60 seconds of tapping then quiet but running like it is out of gas. i then noticed the vacuum gauge bouncing and knew it was not a good thing.



Thanks for all the thought going into this.

Did you think of doing a compresssion check? From what you describe it kinda sounds like some of the valves were hanging open a little. When I was putting my roller motor together, I was using the 8.225" push rods and they wound up being too long. Switched them to 8.150" and all was perfect. I'm using the Bee Hives too, stock irons. I would bet your problem is with the push rods and not the rockers.

 

[Blown&Injected]

Donnie

I did a compression test and they were all between, trying to remember, is was something like 154 to 158 PSI on all except to one that had the broken rocker - that said about 10 PSI

About push rod length.

From an earlier post:

Right now I have about two threads protruding beyond the bottom of the rocker arm and this places the groove in the adjusting screw on center with the oil passage in the arm that feeds the bearings on the rocker shaft.

It looks like there is about .200" (feel safer claiming .187") of total adjusting room in the adjusting screw, considering the width of the groove in the screw and the taper of the edge of the passage in the threads of the rocker arm where the oil passage is located. That means that I could go + or - about .09" on the push rods, currently at 8.050". That gives me the choice of a push rod between 7.96 and 8.14".

Since the adjusting screw's lock nuts have the screw slightly below the level of the top plane of the lock nut, it looks like the push rod can go to 8.125" and still hold the screw in a proper location. Does this sound like it will make a difference?

 

[DonnieShort]

Donnie

I did a compression test and they were all between, trying to remember, is was something like 154 to 158 PSI on all except to one that had the broken rocker - that said about 10 PSI

About push rod length.

From an earlier post:

Right now I have about two threads protruding beyond the bottom of the rocker arm and this places the groove in the adjusting screw on center with the oil passage in the arm that feeds the bearings on the rocker shaft.

It looks like there is about .200" (feel safer claiming .187") of total adjusting room in the adjusting screw, considering the width of the groove in the screw and the taper of the edge of the passage in the threads of the rocker arm where the oil passage is located. That means that I could go + or - about .09" on the push rods, currently at 8.050". That gives me the choice of a push rod between 7.96 and 8.14".

Since the adjusting screw's lock nuts have the screw slightly below the level of the top plane of the lock nut, it looks like the push rod can go to 8.125" and still hold the screw in a proper location. Does this sound like it will make a difference?

It's certainly possible it could help. 8.050" seems pretty short and I would not go shorter. 8.14" is only .01" from the length I used. The oiling slot in the rocker threads have a decent amount of adjustablilty up or down so the length can be off a touch and still work given the adjustment window. Do you have an adjustable push rod you can use to measure for the exact length? When I was doing my motor I bought off the shelf, supposed to work push rods and they weren't even close. My machine shop let me borrow an adjustable push rod to get the measurement and just as I suspected I needed one that was .075" shorter. Put those in and got them adjusted, ran like a top. Good luck, it can be a chore sometimes.