I broke it.

[Rob_RA]

John

Have been thinking the same thing. I have been doing a bit of researching surrounding turbo upgrades and have come accross a few stories of this happenig in the states.

As you have said though, surely if this was the plug striking due to a design flaw it would have happened the first time it was started?

There also seems to be a fair bit talk about No. 4 cylinder running the leanest and pre-ignition??

[spareparts]

can you load up a pic of the plug in question.... to me it looks like the engine is runing lean and melted a bit of the plug and it fell in the cyl

[El-Diablo]

Ive seen it mentioned a few times and have also read of people placing two washers under the plug to prevent it.

Unfortunately there is little if no verifiable problem solving on these engine failures or failures in general with most comments being by internet experts.

It is statistically unlikely however that a large number of failures would occur on a certain cylinder. this would indicate that there is something wrong somewhere in the fuel/air feed to number four in particular.

In regards to whether it is happening it wouldn't take too long to get a head on a measurement machine and check the facing depth of heads with this particular failure.

I'm interested with the photos of the failed cylinder as it appears the combustion chamber is not machined apart from the valve seats. There are two distinct casting bosses in the combustion chamber. Has anyone else had a head off and seen if those bosses re in every combustion chamber? Can you please post pics of the other pistons and combustion chambers thanks.

In the photos it is unclear if something broke off and caused the valve damage or whether the edge of the valve failed. Can you get photos of the edge of the valve at the break to show if its a mechanical or heat failure.

It is unlikely to be a heat failure as the piston would melt before a valve would get broken.

Next question is did something fail in the turbo and send material into the cylinder causing the mechanical damage?

[El-Diablo]

Had another look and the last post may be right failure of the plug tip, tip got under the valve and the valve broke the pieces then caused the further damage in the engine.

Did you find any debri in the intake/turbo or any other locations

[shamrockshirts]

Thats exactly what I'm thinking, Most likely explaination is Pre-ignition causing a piece of the sparkplug to break off and fall in (usually the ceramic first) which then munch's the tip of the sparkplug and causing the cylinder/head damage.

The story of no 4 striking the piston top doesn't make sense to me unless something has changed 1st.

As for it being No4....unfortunately its very common on most engines especially turbo'd when you start pushing them.

In my experience its usually cylinder 3 or 4 are the first to go because they are the last injectors on the fuel rail and the last ones to the fuel feed.
The fuel pressure regulater is supposed to distribrute even pressure accross the fuel rail but when you've used up all the fuel on the rail and there is nothing returning to the tank then there is NO pressure to regulate. So the last 2 cylinders usually are the first to suffer. Ahhh the joys of tuning.

One really good reason to upgrade your fuel pump assembly.

[El-Diablo]

I used to ride kawasaki triples and they were prone to seizing the middle cylinder if you ran them out of fuel. The reason the fuel line to the center cylinder was considerably shorter than the outer two. Kawasaki were too lazy to ever change it.

Its a real pity that a lot of the failed engines on forums never get a real thorough investigation as to root cause. All that happens is Bullsh*t and emotion which doesn't help anyone in the community.

[McCoy]

Because you've had detonation you'll need to look at your turbo too, you may find that is rooted too.

I'd be interested to know what injectors and adapters you were running.

[R4LLI4RT]

all i can say is it look mighty expensive.
I dunno how modded your car is but that looks like a warranty issue.

[Mixedmotorsportmedia]

Exhaust intake WGA tune, lol and yes shaping up to be that way. but good things to come

[R4LLI4RT]

keep us updated with the info
if the case is it covered under warranty that would mean new block yeah?

[mr_evo]

shit aye. all those 1/4 mile runs didnt do you any justice