Failed Rocker Arm

-
Yes, the spring height measurement is not counting the 'cap' ( the retainer). What tool are you using for the measurement?

The issue is that the installed spring height looks to be abnormally short; that is valves, valves seats, retainers, keepers, & any shims. I'd be looking into what retainers and keepers you have first, or if the springs have shims under them. I've been looking at your pix in post #1... are the keepers protruding up out of the retainers? It sorta looks that way. I just wonder if some 10* degree keepers got put into some standard 7* retainers, or some other mismatch is there between the 2. That would tend to push the retainer down. Just thinking out loud....

You have a VooDoo cam with fairly quick ramps. The need for the heavier springs is driven by that. And the springs you have indeed have a pretty low coil bind height.... meaning you won't do a ton better. I don't have numbers in front of me, but I'd not expect the stock spring to be as good for coil bind height.

If I work through your numbers with the increased rocker ratio versus the cam tag, and try to account for lift loss due to pushrods angles, the exhausts looks to be getting in the range of maybe .040"-.060" from coil bind, and the intakes are a bit more. So getting on the verge of concern IMHO....
 
JRapley said:
I'll give it another double check tonight and look at some others. Just to be clear, that measurement didn't include the spring cap.

Out of curiosity, if the springs are getting to the point they're close to binding, is the solution different springs, different valves or both?

This engine isn't necessarily high HP & TQ (just shy of 400HP & 415lb-ft). I'm wondering if there would be any issues to just going back to stock springs.

@RAMM, any thoughts on this? I know you're fairly familiar with these EQ heads.

Thanks
Click to expand...

I think a 1.562" IH is a typo. I'm sure its 1.625 or 1.65 is even more likely. Refresh us on the cam and head combo again please. I know they are EQs and a Lunati cam. J.Rob

p.s. NVM I found the time to go back and read. J.Rob
 
Last edited:
nm9stheham said:
Yes, the spring height measurement is not counting the 'cap' ( the retainer). What tool are you using for the measurement?

The issue is that the installed spring height looks to be abnormally short; that is valves, valves seats, retainers, keepers, & any shims. I'd be looking into what retainers and keepers you have first, or if the springs have shims under them. I've been looking at your pix in post #1... are the keepers protruding up out of the retainers? It sorta looks that way. I just wonder if some 10* degree keepers got put into some standard 7* retainers, or some other mismatch is there between the 2. That would tend to push the retainer down. Just thinking out loud....

You have a VooDoo cam with fairly quick ramps. The need for the heavier springs is driven by that. And the springs you have indeed have a pretty low coil bind height.... meaning you won't do a ton better. I don't have numbers in front of me, but I'd not expect the stock spring to be as good for coil bind height.

If I work through your numbers with the increased rocker ratio versus the cam tag, and try to account for lift loss due to pushrods angles, the exhausts looks to be getting in the range of maybe .040"-.060" from coil bind, and the intakes are a bit more. So getting on the verge of concern IMHO....
Click to expand...

We dont know how OP measured the IH. Calipers ain't gonna cut it. UNTIL you use a IH micrometer AND tap on the valve stem you aren't seeing much accuracy. No way they are at 1 9/16" with those valves.

Talk about a mountain out of a mole hill. A single rocker broke, OP didnt pull the covers to discover 2, 3 , 4 etc.... broken. I use more spring pressure than Lunati recommends because their recommendations are Wrong. Ask me how I know. Pretty sure a rocker broke. EOS. J.Rob
 
Thanks again everyone for the information and replies.

I would definitely agree with Jesse, the fact I cannot get an accurate measurement doesn't help with correct findings on installed spring height. There's really no flat part on the inside of the head casting to take an accurate measurement to.

I'm most definitely leaning towards changing oil & filter, installing a new rocker arm, spinning it over by hand with the valve covers off to ensure everything is moving as it should, and then firing it up and drive on.

My only real concern is if for some reason another rocker goes and I'm not so lucky with the outcome.
 
There should be a way to accurately measure IH with everything mounted... sure others have done it a bazillion times.
'Cause, when you really are near or at coil bind the next rocker will fail soon. So better try to verify that IH or your springs.

JRapley said:
My only real concern is if for some reason another rocker goes and I'm not so lucky with the outcome.
Click to expand...
No need to worry then. As Nm9 said in post 5.
 
@RAMM specs in post #16. But for refresh this was the parts list:

Pushrods: Comp Cams 2112 (7.500" x 0.080")
Valve Springs: Crane 99835-16
Retainers: COM743-16
Valves: Ferrea FERF5003-1 & FERF5005-1

I also did double check the measurement I wrote down, and it was 1.562". Unfortunately I don't have a spring height mic or anything like that. What's your normal procedure for measuring installed height accurately with the spring already installed?

Shoot me a PM if you'd like to discuss offline or whatever.

Thanks
 
You must log in or register to reply here.
-

Back
Top