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Discussion Starter · #1 ·
Hi Folks,

Hoping you can guide me on the correct way to install camshaft and springs or if you think my camshaft is bad.
I replaced my stem valves and put the engine back together. I started the engine and it ran fine for 15 mins at idle. Then cylinder 2 exhaust springs broke. 馃槥. I repulsed the head and replaced both the springs and valves to be safe and put back together. Repeated start - warmed up engine at idle - again misfire and codes came up after engine running for ~ 5 mins. This time one of the new springs on cylinder 2 had broken and also the spring next to it on cylinder 3 ( original spring) had broken.

Hence need to pull head again. Can anyone (e.g. Mike馃榾) tell me what I鈥檓 doing wrong or what the root cause may be. Note it has 75k miles and has been fully serviced and maintained by BMW.
Many thanks
DazzleD
 

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i've seen this before and was the vvt motor had a dead spot in it, so vvt motor pushes the valves out longer and retracts them before piston reaches them so dont hit them ,, when vvt motor sticks or dont wind back in after enough the piston comes up and hits the valve or valves and the ones i have seen tend to push the upright cam follower post up and through the rocker cover ,,
the black plastic metal gasket is also a shim for mesh the teeth
 

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Discussion Starter · #3 ·
i've seen this before and was the vvt motor had a dead spot in it, so vvt motor pushes the valves out longer and retracts them before piston reaches them so dont hit them ,, when vvt motor sticks or dont wind back in after enough the piston comes up and hits the valve or valves and the ones i have seen tend to push the upright cam follower post up and through the rocker cover ,,
the black plastic metal gasket is also a shim for mesh the teeth
Hi Mike, many thanks for the prompt reply. So a new eccentric mirror is what is needed. I should count myself lucky there has been no piston or further damage馃檪. I am going to replace all of the springs on both the intake and exhaust side even though it was the exhaust springs that broke. I am looking at the beehive springs from Supatech. What are your thoughts?
 

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i had one come to me doing it a while ago for engine build i never seen one do it before, i put it back together and did mention to owner motor teeth were well worn but he decided to leave for a while as costs etc,, got it running for iver 3 hors running sweet ,, he collected car drove 60 miles and pulled in for fuel turned car off came out restarted it and then would not run and had repeated the push the follower through rocker cover,, I told him get it AA recovered back to me,, I stripped it found it had repeated and worked out that motor had stuck with valves open and pistons had clipped them, it also locked the camshaft enough to move the timing on inlet sprocket so new stretch bolt and retime fixed that part, i just use factory springs and internals takes away any guess work if thing go south in there,
 

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Discussion Starter · #5 ·
Hi Mike,
I thought I鈥檇 share the pictures of the broken springs 鈥渋n-situation鈥 as it seems to me that the retainers been forced down into the springs (keepers are still intact and the valve can move freely). This was exactly the same as the original ones which unfortunately I did not keep. I鈥檝e also added some pics of the total head for clarity. I have bought some beehive springs thinking there would be less pressure/ load and plan on replacing not just the exhaust springs but the intakes as well. What are your thoughts? Cheers

Daren
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exhaust side that is a new one on me , guess its just a build flaw would check the lifter post has not failed higher than normal perhaps, would also check the timing on it in case there was contact with a piston and spring bottomed out maybe , or might just be weak spring with age from engine being rev'd hard all its life possible,
 

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Discussion Starter · #7 ·
exhaust side that is a new one on me , guess its just a build flaw would check the lifter post has not failed higher than normal perhaps, would also check the timing on it in case there was contact with a piston and spring bottomed out maybe , or might just be weak spring with age from engine being rev'd hard all its life possible,
Thanks Mike,
What I don鈥檛 get is why the one of the new springs broke (originally both exhaust springs on cylinder 2, then a new spring one on cylinder 2 and then an original sling on cylinder 3 breaks)
I was wondering if the camshaft May have been warped? Just clutching at straws. The new beehive are from supercharger so reputable. I assume I will not see any difference in performance?
Cheers
Daren
 

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if camshaft was warped it would just dump all oil pressure sound bad from bottom end,, more likely to do with vvt and vanos system
 
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