I might not be able to repair this one.

[VTRDark]

WTF it looks like it's melted.

(:-})

[Phimosis]

Trying to save petrol and running it lean huh?

[tony.mon]

That's what happens when three out of four valves drop into the combustion chamber.
That's not melting, that's proper mechanical hell on earth, that is....

[macdee]

[VTRDark]

And it's bleeding.

(:-})

[tony.mon]

And it's bleeding.

(:-})

It's bleeding expensive.....

[AMCQ46]

So what do you recon happened to fu k it up that bad? Can't see why high comp or tuning would do that

[tony.mon]

Off the top of my head there was some valves, and half a piston.

Cams were ok, cam journals and cam chains also, manual cct's fitted, of course, and valve timing was still set, so I'm thinking either valve spring float leaving opposing valves able to touch each other, or maybe a valve collet or two coming loose, literally dropping a valve.
Once one's gone, everything else joins in.....

[darkember]

Off the top of my head there was some valves, and half a piston.

Cams were ok, cam journals and cam chains also, manual cct's fitted, of course, and valve timing was still set, so I'm thinking either valve spring float leaving opposing valves able to touch each other, or maybe a valve collet or two coming loose, literally dropping a valve.
Once one's gone, everything else joins in.....

Would the added heating during the London trip have had any bearing on the consequences??

[bigtwinthing]

"course grinding paste"

[Styler4077]

Take the piston out and run a 500cc Storm.
I do want to see the piston when (If?) it comes out.
Any bits make their way past the piston to the crank?

Good luck any way Tony

[AMCQ46]

Off the top of my head there was some valves, and half a piston.

Cams were ok, cam journals and cam chains also, manual cct's fitted, of course, and valve timing was still set, so I'm thinking either valve spring float leaving opposing valves able to touch each other, or maybe a valve collet or two coming loose, literally dropping a valve.
Once one's gone, everything else joins in.....

so are your cam profiles so much more aggressive than normal.........given that you haven't raised the rev limit that can be the only reason for valve float.

but if it is a collet coming loose than is that an assembly issue or a design weakness.

as you can tell I like to know root cause before I would build a new engine, otherwise what is to stop the new one doing the same?

[warby221]

Looks like you had a valve head shear there tone
Only ever seen that a couple of times usually on competition motors or extreme over-revving
Buggers just seem to wave a white flag and give up then do all sorts of damage banging around
First time I’ve known one make it out the engine and in to the exhaust
So you’re looking at head and pistons defiantly shot
Good chance of con rod and bearing damage and a few floating bits off ally finding their way to the parts other bits cannot reach
When you think about what a valve go's through at 10K revs it’s amazing more don’t fail really
Bet it made a hell of a racket when it went

[tony.mon]

Bet it made a hell of a racket when it went

Let's put it this way- I was in no doubt that I was going to need another engine........

I was just surprised that nothing came out through the cases!

[warby221]

lol i bet a case of
sphincter on standby
its brown trouser time