Pics of the motor

I posted a few weeks ago about my buddys b20 vtec that blew up. Well he finally got the pics developed. There not great but here are a few.
http://img.photobucket.com/albums/v220/2crxs/motor.jpg
The center of the piston is gone but the cylinder walls where not very bad.
http://img.photobucket.com/albums/v220/2crxs/ronsmotor.jpg
As I posted before, all 4 valve heads where gone. But the stems where still in place. Its kind of hard to see in the pic, but the entire combustion chamber in the head looked exactly like the top of the piston. Except for the hole. Any ideas on what happend?

wasnt built right is my guess. same thing as ls/vtec you gotta do a bunch of shit with fittings and all.

all the fittings where fine, it ran with the stock bottom end for a long time. then he put high compression pistons(11.5 to 1 i think) in it. And it ran good and strong for a while after that.

looks like a melt down, but why only on 1 cylender, maybe there was something in the cylender and it caused this all to happen. but i dont know

We blew up a race motor out of a GSXR 1100 that looked just like that.We determined the cause was one of the cam gears slipped at 11,500 rpm.

....ok

if i had to guess, id say that the injector failed and it ran lean. the combustion temp would be a lot higher, and that could cause the valve stems to get hot and melt. this is just a guess though.

detonation? weird that it ran well for a while and then that one cylinder gave out. Maybe when he last modded his engine he damaged it without knowing? How long was he running the engine?

This is a pic of when i blew my b16 up..overrevved it. Pretty nasty.http://www.we-todd-did-racing.com/wetoddimage.wtdr/wNzY3MTY4NnM0MTNkZmQzMXk1NDE%3D.jpg
http://www.we-todd-did-racing.com/wetoddimage.wtdr/wNzY3MTY5NnM0MTNkZmQzMXk1NDE%3D.jpg

Damn kpeters, That sux.
He was running it for about 4-5 months when it blew. He said that he was driving normal at about 5k when it happend. Just died. It was put together by a shop in Florida.