Arg...broken rocker plate...

[SHEEPDAWG]

  Ive posted before about a vibration I couldnt find. Im still not sure I've found it but I did find my rear cylinder rocker arm plate broken in half. My questions are: , I found that the front right bolt was extremely loose, not even finger tight. Is this the likely cause?..or an effect of the piece breaking?..also the motor has Andrews37G cams. Did these cams require different valves springs or anything I should know to make sure the previous owner and installer should have used?...if yes what would be the proper way to check them?....Finally, if the poorly torqued bolt wasnt the cause what would be?...This may seem like something youd think id have noticed but I honestly didnt...pretty startling.

[Horizonmech]

Alot of times when a failure like this is found it's a fault of improper torque,..... oil, sediment or some crap was at the bottom of the threads giving the feel of correct torque but in fact no real clampage of the rockers occurred.....Glad you found it before real failure occurred on the road......

[Paniolo]

I had a busted one a couple of years ago. I hear it's a common issue.

[superglidesport1]

Ive posted before about a vibration I couldnt find. Im still not sure I've found it but I did find my rear cylinder rocker arm plate broken in half. My questions are: , I found that the front right bolt was extremely loose, not even finger tight. Is this the likely cause?..or an effect of the piece breaking?..also the motor has Andrews37G cams. Did these cams require different valves springs or anything I should know to make sure the previous owner and installer should have used?...if yes what would be the proper way to check them?....Finally, if the poorly torqued bolt wasnt the cause what would be?...This may seem like something youd think id have noticed but I honestly didnt...pretty startling.

When installing the rocker mounts it's important that the cam lobes for the respective cylinder are rotated to insure that the valves will be closed. This reduces stress / strain on the rocker support while it's being bolted down. In other words it's not opening a valve while being bolted into place. Of course the bolts should be turned in alternately and then properly torqued to spec.

Frank

[Tbones]

Ive posted before about a vibration I couldnt find. Im still not sure I've found it but I did find my rear cylinder rocker arm plate broken in half. My questions are: , I found that the front right bolt was extremely loose, not even finger tight. Is this the likely cause?..or an effect of the piece breaking?..also the motor has Andrews37G cams. Did these cams require different valves springs or anything I should know to make sure the previous owner and installer should have used?...if yes what would be the proper way to check them?....Finally, if the poorly torqued bolt wasnt the cause what would be?...This may seem like something youd think id have noticed but I honestly didnt...pretty startling.

I would say that the loose bolt caused your plate to break and not your cam or valve springs.  Make sure you tap out the holes and then air blow them out real good.  Use red locktite and a good torque wrench.

[bigblock6912]

i take it that you don't have adjustable push rods.

[SHEEPDAWG]

i take it that you don't have adjustable push rods.

I do not.