Broken valve springs; My fault?

[greg88]

I'm in the middle of a BHG rebuild (also my first build ever!!!) and upon stripping the head this is what I discovered.

I have a few more pics, but I'm sure you've all seen your share of broken stuff. :biglaugh: Keep in mind that the spring you see is the larger portion of a Ferrea dual valve spring setup. There are three broken springs in total, all located on the intake side of cylinders one, three, and seven.
Ferrea = the best...right? What could have caused this?

When I pulled the spark plugs, the ceramic was missing on a few. Could that have damaged the valves so severely?

The shop that worked on this motor was really shady. Unfortunately, this only became apparent as the guys dug deeper and deeper into my motor. I don't expect them to pay for a thing, but could it be there fault? I didn't change a thing from the day I picked up the car. Thanks in advance.

 

[supradavenz]

i maybe wrong here but just putting my idea out there.. the fact you used (if you did) old/original valves with high pressure springs caused the valves to much stress and being old and weaker made them break?..

im a true amature but that just what comes to mind.

Dave

 

[GrimJack]

With that level of damage to the top end, I'd be seriously worried about the condition of the pistons...

 

[greg88]

With that level of damage to the top end, I'd be seriously worried about the condition of the pistons...

I'll upload some pics soon.

 

[james_9876]

Just a quick question... where is the 7th Piston on a L6???

Anyway, the only way I know of springs breaking is if you put cams in the motor on worn springs, or if you get used springs out of a different motor with a different cam. Basically metal fatigue.

Did you do any valve work yourself? Could just be worn out. And you may be looking for some pistons.

Later

 

[greg88]

Just a quick question... where is the 7th Piston on a L6???

:biglaugh: Sorry... valve seven. The corresponding cylinder of valve 7/24.

 

[Frank Rizzo]

Over-rev? Valve float?

Seems like the piston contacted those valves at some point in their life.

 

[Frank Rizzo]

You have some major pitting/erosion around the intake coolant passages. I had pitting on my #6 cylinder exhaust side coolant passage but all of my intake passages were flawless.

 

[williamb82]

my guess is you had detonation which broke the ceramic on the plugs as you mentioned. on this cylinder it appears the ceramic got caught between the piston and valves and not only damaged the volave but over compressed the springs and caused them to break. whoever tuned it apparently did a shitty job. id guess the pistons is screwed and possibly the cylinder walls as well as the turbine wheel of your turbo.

 

[IJ.]

All exhausts that were broken?

What condition are the valves in on the broken ones?

How high have you been revving it? (ie standalone or stock ECU?)

What do the tops of the Buckests on those valves look like?

 

[greg88]

All exhausts that were broken?

What condition are the valves in on the broken ones?

How high have you been revving it? (ie standalone or stock ECU?)

What do the tops of the Buckests on those valves look like?

Valves were broken only on the exhaust side of cylinders one and three. Springs were broken on the intake side of cylinders one, three, and six. I was running a maftpro setup for speed/density and 6k was the most I ever revved it.

Honestly, I'm not sure what to make of the pistons/cylinder walls.

It looks like theres some scoring on the cylinder wall with some rough piston edges under that.

my guess is you had detonation which broke the ceramic on the plugs as you mentioned. on this cylinder it appears the ceramic got caught between the piston and valves and not only damaged the volave but over compressed the springs and caused them to break. whoever tuned it apparently did a shitty job. id guess the pistons is screwed and possibly the cylinder walls as well as the turbine wheel of your turbo.
Today 09:03 AM

I was guessing the same. The turbine wheel looks fine from what I can see. It really makes me wonder what happend to the valve pieces. Should I be shopping for a new engine (that I will build myself this time :3d_frown: ) or should I just measure the clearances and see what that tells me.

 

[IJ.]

Greg: My "guess" for what it's worth is it's gone WAY lean under boost and somehow hung the exhaust valves open then torched them.

I can't see any way for Ceramic to hang an intake and even if it did it wouldn't break a spring it would just backfire and clack a lot.

Mine was from too much RPM for too long while too lean....