Can anyone find the rest of my plug?

[Jezza-7]

Well after the melted piston it took me two weeks to get the car running again. So was having it remapped today and just as we were finishing the session, again i lost power but this time no smoke out the rear. When the plugs came out one looked like this and i was wondering if anyone knows where the rest of it is?





Very disappointed as i spent all saturday getting it spot on and then this. Hopefully there isn't too much damage.

[Andy]

If I had to guess, I think that plug is consequential damage from the head dropping a valve/valve seat.

Was thinking earlier, if that's the case - does the person you bought the head off still have the receipt from Jabba?

[Jezza-7]

Ah good question. Will find out.

Head will be coming off tomorrow so will see the outcome.

Cheers again for today mate. Learnt a lot as well. 

[Robin]

Very similar to what happened on mine. Mine was due to the spark plug thread being retapped and helicoiled however the drill drilled away some of the valve seat which then failed.

[vwmk3jon]

Ouch!

[Andy]

I didn't realise that your head had died too Robin!

[Robin]

That was a good couple of years ago if not longer, I was running the lader back then with 150bhp.

[Jezza-7]

Found it!! Pics to follow!

[Andy]

Pics pics pics! Fingers crossed it's not seriously bad news.

[Jezza-7]

Right....

When i took the head off with the inlet attached, deciding not to look at the block until the head was removed, it rattled a little and i knew straight away that there was a lot of FOD inside.

I will start off with the least damaged.... er parts? lol. Enjoy!

No 2 and no 3 on the head appear to be fine and they are not bent. But the rest will tell you more about the damage.

Here is no1 inlet/outlet valve on the head, inlet bent but the exhaust is not bent.



And from a different angle



No 2



No 3



And well whats left of no 4






Right now the bottom end

Starting with no 1 and debris



No 2



No 3



And again whats left of no 4 and the remaining piston, this was the shocker for me  but i did find some of the spark plug in the swarf.




And the valve







The cylinder bores 1,2,3 are fine and have no damage so that was good but unfortunately no 4 had damage.

This is the rear of the block



And the side of the bore next to the no3 wall



Whats your thought on the no 4? Do you think the damage is too far to just put a new piston in it.

Other option is to get my old block re-bored and get forged pistons.

[hayesey]

holy shit!

no way you'll get away with just putting a new piston in there, absolutely no way.

Any ideas what has caused this? 

[Jezza-7]

I can only think of valve clearance. Its weird how no 2 & 3 valves are fine but no 4 speaks for itself and no 1 only has the inlet valve bent and the exhaust looks ok.

Annoying really after buying the block and bvh. Thats about £600 down the drain. But the cam is fine.

At least i have the old head still.

[Yoof]

Plug deffo a result of valve failure.

I'd have a chat with whoever did the head...

Block needs an overbore to be used again, I'd also check the rod is still straight (infact I'd frame the piston/rod from no. 4!)

Strange the inlet on No.1 is bent, are there any witness marks on the piston? Also did you manage to check the cam timing post failure?

[Andy]

I checked the vernier hadn't slipped at the side of the road - though that's not to say that the belt hadn't skipped.

No. 4 drops a valve/seat and the consequential seizure bends the rest?

[Yoof]

Just noticed you havn't got a valve seat...