DDK - Die Deutschen Klassiker

JohnM posted a great thread (now in the 911 Technical archive) of his engine rebuild following an exhaust valve failure

http://www.ddk-online.com/phpBB2/viewtopic.php?t=17139

well this is what I found yesterday after breaking down on saturday - just looks a bit too familiar, but this time a dropped inlet valve









Not much left of the sparkplug electrode either (sorry for the poor pic)



Remains of piston #1 and the valve that I was able to fish out



So looks like I'm going to be busy in the next few weeks, splitting the case tonight

Bit of elbow grease and emery paper and it should be useable again....


Edited: Sorry, that didn't sound very sympathetic did it - apologies, hope it's not off the road for too long!

ouch

Let me know if you want any help, I' can pop down one evening for moral support etc

Hi James

the pics look very sorry and a little too familier. Was one of the head studs snapped on the failed pot?

Let me know if I can help in any way.

Kind Regards

Ouch! Thats really bad luck James, a sorry sight to see

Did it fail under load.....at high revs etc? Did you get any warning?

James

Have you got any history on the engine and whats been done?

Kind Regards

John - no failed nuts or studs - all looked good when stripping down, although I am going to try to retorque the heads back on tonight before I strip it to see if the studs are / have been stretched pulled previously as they were very rusty (Tip from your apprentice )
Will check through the history file I have on it tonight for any previous work.

Doug - I was pulling out of a junction from first into second, fairly low engine speed. Had only being going a couple of miles so engine still very cold, did have a noise earlier in the day but nothing that would have led me to believe it was about to detonate

James

What a bummer

I hope your rebuild goes well and your car is soon back better than ever.

James, I think that the noise earlier in the day was probably a chain tensioner starting to fail - the resultant cam timing fluctuations have caused the inlet valve and piston to collide repeatedly, this is why there is so much damage to the piston. The head of the valve has snapped off and then been crushed between the cylinder head and the piston. I have a good cylinder head and maybe a cylinder barrel but no piston, you can have these for postage costs (and maybe make a charity donation via Barry !)
Hope this helps.

Chris

Chris - my first thought too was the chain tensioners, but I only replaced mine less than 1500 miles ago with new 930 types. I made sure that I bled them too before installing. The first thing I checked when I pulled the engine was the tensioners - and they were spot on
I had been having mixture problems with the MFI and think it was set lean (wouldnt idle when warm and cylinder number 2 looks pale around the edges in the picture) wasnt sure if this might have contributed to the failure of the valve?
Re your most generous offer, I'll definitely take the cylinder head off you, but will probably replace the cylinders and pistons with new (barrel number 6 didnt survive unscathed either ) I'll drop you a PM now
Many thanks indeed

bad luck James, but thanks for sharing the pictures with us! Hope you get it sorted out OK.

Oh dear James, sorry to see this. It must be quite unusual for an inlet valve to let go?

I assume you'll contrive a way of measuring the con-rod lengths when you've got it apart just to be sure that the impact didn't affect it?

Best of luck with getting it sorted, you certainly don't seem to have lost much time so far .

butzsi wrote: I have a good cylinder head and maybe a cylinder barrel but no piston, you can have these for postage costs (and maybe make a charity donation via Barry !)
Hope this helps.

Chris

Top man, very generous Chris, thank you!

If you do decide to take Chris up on his offer I have some spare 2.2E pistons...... again just for postage/charity contribution.

Alan

Alan.UK wrote:If you do decide to take Chris up on his offer I have some spare 2.2E pistons...... again just for postage/charity contribution.

Alan

Hurrah for DDK!