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

[Blown&Injected]

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

 

[CTX-SLPR]

Could your pushrods be deflecting? I know its an outside chance with the beehives but thats about all I can think of. I hope I don't have this problem when I put mine together with its custom 8.125" pushrods.

 

[Blown&Injected]

I do not think so as even the one that was on the broken rocker arm is still straight

 

[Russ Merritt]

What lifters are in it? What ratio rocker arms?

 

[Otto J]

How did you check pushrod length?,Make sure your adjusting screw isnt to far in pushing the cup out of the rocker to far

 

[Blown&Injected]

Russ:
- It they are Federal Mogul Performance Performance Parts # HT-5000RA roller lifters. I have read that the roller lifters are all the same but it seems that I have heard about other types???
- It has the 218/212 cam, I think the lift is .498 - cam card is not near me right now. Do not recall the centerline, but I did degree it and advanced it 2* to get it exactly right.
- Beehive springs with the +.050 retainers and 10* locks = 1.630" Installed height. Did not measure for coil bind as at max lift there is lots of space between the coils. Also no interfearence with the retainers/rocker arms.
- Harland Sharp 1.60:1 roller rockers.
- 8.050" push rods .080 wall, forget the diameter but it seems to fit the cup in the adjusting screw as good as can be (not like they are so wide they do not set into them or so thin they rattle around with room to spare).

KLHAMMETT:
I know most people seem to require longer push rods, but when the vendor sent me the entire set-up that had 8.120" rods, it set the adjusting screw for the rocker arms so high that the oil passage was not lining up with the passage that feeds the roller bearings on the rocker shaft - Harland Sharp says there should be about two threads sticking out beyond the bottom of the rocker arm and that is where they are. The witness marks that the roller tip leaves on the tip of the valve stem perfectly splits the centerline of the tip on the stem.

So to answer your question, I calculated the length needed to put the adjusting screw right where Harland Sharp says it should be and subtracted that length from the push rods I was first sent.
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It has been suggested that the engine stopped with the funny lifters sitting on max lift, the lifters bled down and possible got stuck down. But now upon thinking about it, if that were the case it should have ticked from the very second it started, but I was parked for about 15 minutes and then drove for about two minutes before it started ticking - then a minute later broken rocker.

 

[TurboTR]

Could your pushrods be deflecting? I know its an outside chance with the beehives but thats about all I can think of.

It's a great chance actually. From what I've seen the regular old 5/16" .080" wall pushrods flex like crazy in our mills, even with flat tappet. Especially on the exh side. Having a roller probably just makes it that much worse. We have pretty long pushrods in our engines. The best plan is to use (much) stronger pushrods. It takes some work to get them in, but is worth it.

TurboTR

 

[wbrophy]

Space in the valve train is coming from somewhere? I have a 224/224 hyd. roller that has been in my car since 1999/2000 with shaft roller rockers but I run approx. 150 lbs. seat pressure and 350/360 lbs. over the nose (dual springs, .575 lift w/1.65 ratio) and no problems so far. Maybe the springs are not controling the heavyer roller lifters, etc. PS: also check that the pushrods are not rubbing/binding in the heads in the guide holes.

 

[Lee Thompson]

installed height

1.63 in stalled height will make for some serious spring pressure. I believe your problem is in this area.

 

[Louie L.]

Pushrod lenght is also critical when using stock rockers-shafts with a roller cam. Back in the day we used to break rockers shafts all the time. Just didnt take the time to measure.. and re measure. I have been runing stock rockers on my roller cammed, iron headed motor and stock high mi shafts. No issues in over 1.5 years

 

[Blown&Injected]

1.63 in stalled height will make for some serious spring pressure. I believe your problem is in this area.

I was wrong about the Installed height. I was thinking the specs on the springs were set at 1.700", and I recall being .070" under, but I have now pulled the cam card and box the springs came in. The springs are spec'ed at 1.800" on the box. That means I am at 1.730" - .528" (max gross lift) = 1.202" - .040 pre-load = 1.162" - 1.085" (coil bind) = .077" extra space.

Closed Spring Pressure = 152#
Open Spring Pressure = 317#

 

[wbrophy]

What?????

Preload does not change a thing.
(.117 TO COIL BIND) which is a good-er thing than .077. :biggrin:
PS: Your spring pressures are in the ballpark for a hyd. roller IMO.

 

[Mike Licht]

Spring pressure is fine. The pushrods are wrong. Rotate the motor until the number one intake rocker is at mid lift, .264, look at the roller on top of the valve stem and see if is exactly in the center of the valve stem. If it is to the intake manifold side the pushrod is too short, if it is towards the outside of the motor it is too long.
Mike

 

[wbrophy]

You could also put a little blueing on the valve stem tip and rotate the engine a few times, than take the rocker arm back off and check the contact pattern.
If in the center than great but as long as the pattern is .030 from the valve edge you can live with it. Due to cam lift, lifter length, decking, etc. it's not uncommon for the pattern to be a little off center.

 

[Blown&Injected]

wbrophy, I included the pre-load as a, what if, incase the lifter had pumped up even though it happened at about 50 MPH in 4th gear and the converter locked-up = low RPM's (<2000 RPM's) and conversely low oil pressure (about 25 psi).

Mike, I sent the rocker set back to Harland Sharp so I cannot do the test you mentioned right now.

However, the witness marks the Roller Rockers left on the tips of the Valve Stems split the center line. The adjusting screw on the arms are such that there are about 2 threads exposed out the bottom of the arm and the oil groove in the screw lines up with the passage in the arm that feeds the bearings on the shaft. It seems that if the push rods are longer or shorter it would then cause the roller tips to not split the centerline as the rocker goes through its travel. If anything, they super slightly favor the outside of the engine. I am using 8.050" push rods right now.

Please keep the think tank going even if reaffirming your current idea about this issue - got to get to the bottom of this, it is driving me crazy.

Thanks.

 

[Lee Thompson]

push rod lenght

On our shaft mounted rocker system--pushrod lenght will have 0 effect on the roller to stem pattern. The only thing lenght will change is how far you run the adjusting screw in or out. The height of the center line of the shaft, the height of the tip of the stem and the distance from the shaft to stem will remain constant. That is why some of the higher priced shaft systems come with shims to adjust the shaft height. Think about it.

 

[wbrophy]

On our shaft mounted rocker system--pushrod lenght will have 0 effect on the roller to stem pattern. The only thing lenght will change is how far you run the adjusting screw in or out. The height of the center line of the shaft, the height of the tip of the stem and the distance from the shaft to stem will remain constant. That is why some of the higher priced shaft systems come with shims to adjust the shaft height. Think about it.

Good info for everyone but I think he is using the Chevy style set-up.

 

[Blown&Injected]

Lee very good point.

I have spent some time last night playing with some objects rocking on a fulcrum and considering the nature of the fixed height of the valve stem and the rocker arm on the shaft (I am using Shaft mounted rockers, Harland Sharp 1.6:1 ratio roller rockers) and it seems that the only issues for this set-up is that the Installed Height is good, I am at 1.730", and the position of the adjusting screw on the push rod side of the rocker arm - that is dictated by the push rod length.

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?

Thanks for the help!

 

[Lee Thompson]

Imo

No As long as you keep the groove in the window and go 0 lash + .030--I don't see that making one bit of difference. Have you pulled the lifters? I ask if the dics are up against the snap ring.

 

[Scott Atk]

Did not measure for coil bind as at max lift there is lots of space between the coils.

Could this be your problem? I have never run the beehives, but it is my understanding that they are supposed to "stack up" in the lower section, this is how they control harmonics. This is why some have had problems with beehives setting off knock sensors. If you have space between all coils then its possible your installed height is too tall and your losing your pushrod - rocker arm connection at high RPM?

You also mentioned using Harland Sharps. Do you have GN1s or irons? I couldn't make my HS rockers work when I switched to GN1s. Geometry was off due to the different valve spacing.