Threw rocker arm - on the intake side ???

[Master Chief]

Hi guys.

Just had bit of bad luck - i guess having to do with my attempts to tune the Anti Lag Launch Control, or hittinig the limitter meaby earlyer that day.

Went to the dyno - seemed to be a bit low on power, so i checked the Spark Plugs - Number 1 seemed to be fouled, and looking down the bore, there was a small puddle of liquid - seemed like oil or meaby fuel - not water.

Anyway, desided to check it back home, so as i was leaving the dyno - drove for 50 seconds, and the engine stalled - upon starting i heared a clinking noise and the engine died again - only menaged to run it, holding the throttle open at above 50% - and it was working on 3 cylinders.

Towed it home.

Did some LeackDown test's on it - and it was pretty low on cylinder 1.
Took the valve cover off, and found out the ROCKER arm, on the intake side, of cylinder 1, was just sitting off the valves, on the side - held in place only on the LIFTER side, by the GREDDY LHA STOPER - ocationaly hitting the Cam lobe on the side - the two shims, just sitting on the bottom of the head.

Obviously this would explain why the car was on 3 cylinders, but i wonder what could have caused this in those 50 seconds , and wheter there was already something wrong, an i just didnt notoced it !?!?


I would have expected, antilag, to cause a brocken rocker on the EXHAUST SIDE , not a thrown rocker on the intake side.
Has this EVER happend to any of you ?

My concern is that the Leackdown showed much lower on the No.1 Cylinder, as compared to the rest.

Could be the valves are not sitted 100% in place, and need a bit of runing to sit back ? I did, remove the intake CAM, replaced everything back to its place, and playing a bit with the crack pulley - managed to raise the Leack Down result a bit - but still lower than the rest.

On the way i bled the LIFTERS on the intake side, and rechecked clerances of the shims etc.

Could something like the above, cause the valve to BEND or something ?


Here are some photos :

This is how i found it :
http://www.max-tuning.com/gallery/mypics/rocker/r3.jpg

And the Damage (so far...)
http://www.max-tuning.com/gallery/mypics/rocker/r1.jpg
http://www.max-tuning.com/gallery/mypics/rocker/r2.jpg

I did some micro polish, to remove any burs, but i obviously cant remove the scratches - i just hope it will still be ok, as the ar on the side of the lobe of the cam, and most of the contact surface of the lobe with the rocker arm is still smooth.

The scratches on the retainers, shouldnt cause any problems, i think.

I have Rocker Arm stopers, as i said.

I am trying to understand why would a VALVE bend - and how - if the rocker arm moves.
The rocker arm is the only contact between the valve and the Cmashaft. If it moves out of place, than the valves would stay closed - no ? I closed, than how could the hit a piston ?


UPDATE :
About my REV limmiter, its set at 8000RPM - the thing is that although i may have reached it earlyer that day - the car seemd fine when i left the DYNO that evening - and all this actualy happed, 20 meters down the road from there.

Also, i have meassured the TIPS of the valves, using the below instrument - used for selecting the right shims to use - and they both meassure within spec.
http://www.max-tuning.com/gallery/mypics/sr20det/mt_quality/mt-quality7.JPG
If a valve was bend, wouldnt it be lower on the top, than a streight valve ?
Unless both valves got bent the same...

[godsmack]

well i know that a common thing with sr's when the arm comes off you will usually bend a valve. Now as for measurements??? I'd say pull the valves to check.

[drifter_for_life06]

agreed, you're best bet is to just pull the valves out to check. The scuffs on the retainers should be fine, unless they are deep enough to alter the structural integrity of the retainer..but by the picture it doesnt look to be that bad. I personally wouldnt use the cam with those scars on it...but thats just me cuz im picky about shit being "near perfect" where that is not.

my :2c:

[Master Chief]

I am trying to understand, what would cause the valve to bend.
I mean, if the rocker jumped out of place - the valves would stay shut - and as such, not hit the piston.

Could it have bent on the other side - i.e. where the rocker sits on ?

Has anyone that had this happend to them - can confirm about the valves ?

Thanks.

[beyondstock]

The way the Camshaft and rocker looks it seems as if the rocker arm got lodged sideways between the cam and the valve. I would guess two things happened. Being lodged at the angle it was at the valve opened to far or kept the valve open and contacted the piston. OR the pressure of the camshaft lodging that rocker arm was kind of sidways and caused a slight bend?

I really dont know I'm just shooting the idea out there...

[godsmack]

The way the Camshaft and rocker looks it seems as if the rocker arm got lodged sideways between the cam and the valve. I would guess two things happened. Being lodged at the angle it was at the valve opened to far or kept the valve open and contacted the piston. OR the pressure of the camshaft lodging that rocker arm was kind of sidways and caused a slight bend?

I really dont know I'm just shooting the idea out there...

ya those scuffs mean that arm lodged and more than likely pushed down the valve at the wrong time. valves aren't that strong when it comes to something like this.

[juggernaut1]

I mean, if the rocker jumped out of place - the valves would stay shut - and as such, not hit the piston.



Well assuming your doing 8000 when this happened (and I'm not saying you were) the cam would be rotating at 4000 rpm or 66.66 times a second.

That means when the rocker is thrown it has 1/60th of a second to clear the cam lobe before it gets pounded back into the valve or anything else in its way. The chances are it will hit the valve and your retainer shows it was hit. Whether it hit at the wrong time to hit the piston is another question. But even if it didn't hit the piston any side load applied to the valve when the rocker dislodged could also potentially bend the stem.

[Master Chief]

I see what you guys are saying. I'll try a compression test - and if it doesnt vary too much from the other cylinders. i'll leave it like that for now.
I have a spare head to build properly - so i'd rather to that, then take off the head, replace valves and gasket, and put it back.

I am wondering however - on a SOLID LIFTER setup, what would prevent the rockers, jump off the vaves, like it happend to me here ?

[juggernaut1]

You could remove the spring and rotate to valve and measure any movement with a dial guage - this would be a quick test whether the stem got bent.

[drifter_for_life06]

I am wondering however - on a SOLID LIFTER setup, what would prevent the rockers, jump off the vaves, like it happend to me here ?
Nothing. You cant 100% guarantee a rocker wont jump off. RAS just try to help, whether or not they work well enough to be bought and used is debatable

[Master Chief]

Good idead Juggernaut.

As for the RAS - as you can see in the photos - it actualy caught the rocker on the lifter side, so it at least prevented it from flying all over the place, and causing more damage.

The thing is, that it really didnt look as this could be prevented - thats what iam worried about.

Also did a compression tes today - apperantly Cylinder 1 is about 152-155 PSI, where the others are at about 160-162.

I wonder if this small diffrence is worth taking the head apart etc - what do you guys think ?

It might get better in time as i belive its a really small bend if there is one, and i am sure the valves never hit the cylinder.