 Why did my rockers break? 6 cylinder |
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| David Stowers |
 May 16 2022, 09:32 AM
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Member  Group: Members Posts: 99 Joined: 28-June 12 From: UK Member No.: 14,613 Region Association: None  |
Hi all,
All 3 exhaust rockers broke on one side (4,5,6) when I started my engine for the first rime after cam and rocker re grind. What’s the likely cause here folks? Thank you |
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| fixer34 |
May 16 2022, 05:44 PM
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#2
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Senior Member Group: Members Posts: 1,268 Joined: 16-September 14 From: Chicago area Member No.: 17,908 Region Association: Upper MidWest 
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Assuming the pistons hit the exhaust valves while still partially open when at top of stroke. Cam timing needs to be off quite a bit (delayed) if it hard hard enough to snap the rocker arms. By any chance did you/someone forget to insert the locking pin into the cam gear. Tighten the cam nut and it will rotate by hand and everything looks good. Under power, the cam gear slips and that's it...
If you are real lucky it didn't trash the valves or pistons. |
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Posts in this topic
David Stowers Why did my rockers break? 6 cylinder May 16 2022, 09:32 AM
Superhawk996 Lots of possibilities. None of them good.
I... May 16 2022, 09:38 AM
David Stowers
Lots of possibilities. None of them good.
I... May 16 2022, 09:42 AM nditiz1 At what point did they break?
Did the cam timing ... May 16 2022, 10:02 AM brant I've been told in the past that some year of T... May 16 2022, 10:52 AM porschetub
I've been told in the past that some year of ... May 16 2022, 07:03 PM rgalla9146 :agree: all of the above.
Consider yourself a... May 16 2022, 04:02 PM mb911 Ugh what a sick feeling. My guess is wrong cam tim... May 16 2022, 04:31 PM euro911
:agree: May 16 2022, 05:04 PM r_towle The valve hit the piston.
Either valve timing or c... May 16 2022, 06:07 PM sixnotfour Bad News, you bumped cast pistons.... May 16 2022, 09:07 PM mepstein cam timed 180 degrees out? It happens. May 16 2022, 09:19 PM sixnotfour
cam timed 180 degrees out? It happens.
:beer2: May 16 2022, 09:44 PM Retroracer Like @FIxer34 suggested, missing or sheared cam ... May 17 2022, 07:18 AM burton73 Cam timing on my 6
This is not so easy and you ... May 17 2022, 10:43 AM sixnotfour Many shops have the tools ,but have done 180 out a... May 17 2022, 08:15 PM Luke M Have you checked the valve to piston clearance ? T... May 18 2022, 08:13 AM ClayPerrine I have lots of experience with setting the cam tim... May 18 2022, 11:04 AM Jake Raby
I have lots of experience with setting the cam ti... May 18 2022, 08:01 PM |
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