One more...

 

Ohh yeah, forgot I was supposed to be doing this

 

 

Bugger, took a couple of photo's but they're on my phones memory card and my card reader won't accept this type of card

To be honest not too exciting photos. Significant bore scuffing, material ripped off the piston crown, cylinder head warped by 300 microns and cylinder head gasket.

Most don't photo well

 

What can I do to motivate you Fluffy? Get down to that pool and everything will fall into place.

 

Now that looks exactly like my old cylinder head, except there was only half a valve head stuck in the inlet.

Did you ever find out what caused your failure?

 

Obviously the valve has dumped into the chamber hence the damage. To do that normally means either the cotter has released at the top or the valve has bent causing it to stick. If it sticks it'll be repeately stuck until it fails.

Unless it was bent when it went in (not likely since they'd have trouble assembling it) then the only way it will bend is by some form of debris in the bore or the valves own inertia overcomes the valve spring allowing the piston to strike it.

The former is unlikely if the air filter was attached properly.

Therefore I'd go for the latter. The latter is caused by engine over-rev. I wouldn't be able to tell for cerain without seeing the short block though.

 

When my engine blew there was no evidence of an over rev in the ecu. The valve stem retainer was also undamaged.

I certainly didn't over rev the engine, though i was the 3rd owner.

It was replaced under warranty anyway so water under the bridge but i'd still like to know why it failed.

 

Problem is when you over rev you tend to bend the valve and then the valve sticks causing it to get hit repeatedly by the piston until it does break. Depends how bad the contact is to how bad the bend is and hence how long to failure. In your case I'd say it was actually a fairly small bend.

The reason I say that is when I've seen similar it's tended to knock out both exhaust vlaves in the same chamber and also take out the intake valves in secondary damage.

The lack of split retainer is also worth noting for the same reason. Cotters work by the tension in the spring holding them shut in the retainer. Smash a piston into the valve and they'll try and ride out of the groove in the valve. This forces them to spread splitting the retainers if hit hard enough. That would support the idea of light damage. Since yours weren't split.

How long after you got the car did the engine fail?

 

3k miles, and it was an inlet valve on cyliner no4 that failed.

Exhaust valves appeared to be fine, though i only got a quick look at the damage.

When the engine actually failed it had only just started to warm up and revs were at approx 4k.

The report that came from the dealer said manufacturing fault in the valve stem.

That being said, the dealer failed to clean the inlet manifold out properly (inlet valve failed pushing bits of valve back into the inlet manifold) and then tried to get me to accept engine no2 when it was knocking like ####.

Engine no3 was a cracker though!