ADM

Excuse the long post, as I thought the details could help diagnose the reason for the failure.

After a month of using my car after finishing my cam swap, I was data logging in my car to get readings as I was having some mis-firing problems there was a big difference between the readings of my O2 sensors. After my run I got a loud knocking sound in the engine bay, which sounded like it was coming from the lifter valley, more towards the passenger side.

I stowed the car for a long time as I suffered an injury and I could not move much. After my recovery, I took apart my opti, had some oil in it from a leaking water pump driveshaft seal. Cleaned it and put it back on. Fired it up and the car ran again, but was missing like crazy. I posted a thread on here and the guys said maybe its the Taylor wires I installed.

The knock was still there of course, so I stowed the car again until I the weather was forgiving enough to work on the car (summers are at 45 degrees C here, and humid).

I suspected a collapsed lifter since the noise sounded under the intake. I thought I would take inspect the valvetrain first and then proceed to removing the intake.

Driver side, perfect and neat.

Passenger side, the #2 cylinder intake valve rocker arm had come off the spring, and sitting on the side of the spring towards the #4 cylinder intake valve spring. There were not in contact with eachother, thankfully.

I took off the rocker arm, the polylock nut was loose as expected because there would be no load from the spring. I removed the pushrod and inspected it, no visibile damage

I then inspected the rockerarm carefully, the tabs were damaged (I am using self aligning rocker arms). It seemed like they were hitting onto something during operation, but the valve retainer did not have a single mark on it. I also inpected the valve tip, same. I will post pictures of the tips.

The pushrod was still sat in the lifter cup, so I think the sound was the pushrod hitting the head at the pushrod pinch or the lifter jumping up and down on the cam?

Could my cam have been damaged from the free moving lifter? Or the lifter be damaged as well? I am considering pulling the intake and also removing my cam to inspect it.

Now, about my rocker arm problem :

Could I have encountered valve float? I am running 918 Beehives and the retainers required for them. If the tabs were hitting the retainer, I would believe they are made of a much stronger material and hence not even a scratch on them, but that would mean a clearance inssue. I used 1/2 turn of preload for my valve lash. I checked all the other valves, and there was ample clearance between the tabs and the retainers.

My next step will be to install one of the other rocker arms onto that valve and check the clearance with feeler gauges.

I checked the pushrod it on a glass table, and it was thankfully not bent. I checked it again yesterday at work on a workshop surface plate and it was again dead on straight.

My problem is that CC does not make the Pro Magnums now, only Ultras. I don't want to buy a whole set of rocker arms again as I can't afford them at the moment.

First I want some help on diagnosing why this happened and how to avoid it in future. I want to learn from my mistake.

I was also looking at Harland Sharp, Scorpions, Lunati and Howard Cams rocker arms as alternatives to buying the Ultra Pro Magnums.

Would it be a better choice to switch to 7/16 ARP studs and rocker arms this time, and go NSA too? Would I need to re-measure my pushrods?

I am running a CC503 only, was shifting at 6500 RPM.

fergymoto

iTrader: (129)

You say your poly lock "was loose as expected because there would be no load from the spring." It should not have been loose, even with no spring. The nut itself is tightened down on the rocker fulcrum, then the inner locking screw tightens down on the rocker stud. It should have still been tight.

Sounds to me like the inner locking screw was loose or came loose, allowing the rocker to become way loose and jump off the valve.

I would definitely pull the intake and make sure the lifter and dog bone are still in place and oriented correctly. I have seen where people broke a rocker arm or had one come loose and because there was no downward pressure on the lifter, the cam lobe coming up would just throw the lifter up, knocking the dog bone out of the way and bending the spider that holds the dog bones in place.

With the intake off you will be able to see the cam lobe by looking down the lifter bore. Probably no need to take the cam out. Check the roller on the lifter too and see if it has any damage. If the roller is undamaged, the cam lobe probably is too.

ADM

Here are the pix, excuse the quality, camera phone

http://img46.imageshack.us/i/070920103061.jpg/
http://img259.imageshack.us/i/070920103058.jpg/

And thanks for the advice, I completely overlooked the locking screw coming loose.

I will remove the intake and inspect the lifter and cam lobe. I pray it did not get damaged.

fergymoto

iTrader: (129)

Is there any damage to the pushrod cup or the roller on the roller tip of the rocker? I don't see any but like you said the pic isn't good. If the spring cup and the tip look undamaged and the tip still turns freely it is fine.

SS RRR

iTrader: (2)

If the lifter is not properly pumped up there can be a little bit of play even with the valve correctly adjusted. Not sure if it's enough for a SA rocker to jump the tracks, but regardless...

speed_demon24

iTrader: (6)

You lost 5mph out of nowhere in your trap speed?

ADM

The pushrod cup is not damaged and the roller tip turns freely without any restriction whatsoever.

However, if you look closely in the pics, the side tabs are damaged but not wiped out. The insides are gouged and that makes me not want to use the rocker again as I am worried about it slipping off. I will try to get a better and clearer picture of the damage.

ADM

First time I adjusted the valves, the engine would not run. The lifters pumped and kept the valves open.

I redid the valve lash and it fired right up. Should I have re-done them again after running the engine?

Do you suspect that one lifter might have gotten damaged and caused the play?

leadfoot4

iTrader: (1)

I've been messin' with cars for a little over 40 years, and when it comes to getting hydraulic lifters adjusted accurately, the only way I've been truly successful is to do it with the engine running. As a side note, I had the CompCams 875Rs in my LT1 for a while, and the only way I could get them right, was not only with the car running, but with the engine fully up to temperature, to allow all the parts (especially the aluminum heads and rockers) to expand to their running dimensions.


BTW...I think your problem was something that happened to me a number of years ago. While setting the lash on a Pontiac T/A that I used to own, I was distracted for some reason, and didn't get the poly lock tightened down correctly. About 25-30 miles later, it backed off, allowing the rocker arm to jump to the side, just like yours did. I wasn't as lucky, however, as the pushrod popped out of the lifter and broke up, ending up in the oil pan.

BALLSS

you should be able to just but 1 RR and replace it. the tab damage 'may' not cause frther problems but if it were my car i would replace that RR. Had one do the same thing with a Crane RR and i bought one to replace it. My error on valve lash on that valve was the cause.

The only way to really know if lifter or dogbone are damaged is to pull them. I doubt they are but again the only way to confirm is to inspect.

I agree you most likely erred in tightening the polly on that valve and it got lose and came off.

I would replace RR and 'correctly" relash all the other valves. I use the #1 TDC and do the associated valves and then rotate to #6 TDC and do the same. I run the motor first to get it up to operateing temp and then let it cool about 15 min since my coated headers cool quickly but the cast iron block and internals stay pretty warm.

SS RRR

iTrader: (2)

Reason being is you adjusted them far too tight. It can be tricky to adjust lash with a lifter that is not pumped up, and yes, if you have initially adjusted valves w/out the engine running and knowing the lifter is not pumped up, it is a great idea to either run the engine for a few minutes and adjust or adjust while the engine is running.

ADM

The first time the lifters had no pressure. After cranking the engine over numerous times trying to get her running, they did pump up and keep my valves open. I did undo all the polylocks and readjust to 1/2 turn as I did the first time.

UPDATE:

I just pulled the intake a while ago. Inspected the spider and as fergymoto predicted, the #2 leg was bent upwards. I removed it and gently bent it back inline with the remaining legs and checked it with a steel ruler for alignment.

I inspected the lifter guide, no damage. Also, the lifter is not damaged either and the wheel turns freely, not even a scratch.

Used an inspection mirror to see the cam lobe since you can't actually look down straight through the hole due to the head protruding inwards of the lifter valley and its not worn or scratched.

I just wanted to ask you guys, does it matter which side the oil hole is on the lifter when you put it back in?

Thanks to all those who offered their assistance, advice and experience to help me out.

ADM

someone must know the answer?

speed_demon24

iTrader: (6)

Post up pics of your valvesprings/valves. When I put 918's on my stock valves there wasn't enough room between the valve tip and retainers for the s/a tabs which could have caused this problem.

speed_demon24

iTrader: (6)

It doesn't.

ADM

I am going to install the rocker arm today and check clearance with a feeler gauge and compare all the other rocker arms. There is no damage to the valve stem tip or the retainer which is what made me isolate that as the problem, but you can never assume. Always measure and be sure.