Valve Failure?

[Ted Jannetty]

Actually it's one of the three small valves... so it's an intake valve and not an exhaust valve.
Still can be caused by thermal fatigue...

How was the valve lash? Excessive clearance causing pounding?

I am going to leave that one alone LOL.

 

[jhlarsen]

Do you have any timing advance control? If you wern't under boost one reason I can see that happening is if you have some major timing advance in your low and mid range.

I'm running rb3 with a map from dave at hurricane.
But were i was in the map at the time, i don't think it's to much advance.
But i will check in to that. Thanks for the heads up

i think its from the carboned up valve.carbon produces heat and i think thats what caused that

The carbon build up may be form the long drive down from the mountain..

Thats what i was thinking !

I'm running a NFS2 header with a 2871R turbo mid mount.
i gess the cyl next to it can say somting about how the engine/map is.
It was a long way down from the mountain on tree cyl. so i don't think it would look like this if i haven't driven it down..

And it is an exhaust valve

 

[mbarryracing]

Actually it's one of the three small valves... so it's an intake valve and not an exhaust valve.
Still can be caused by thermal fatigue...

How was the valve lash? Excessive clearance causing pounding?

I am going to leave that one alone LOL.

NOPE, I"M WRONG.
SORRY TED. Just expanded my screen to see the rest of the picture and the orientation of the cylinder next to it, Duh it IS an exhaust.
Man, I'm having a bad day...

 

[347strokin]

Just out of curiosity, how many kms on that motor and how many boosted?

Why does the next cylinder over look so different? Was that bad hole somehow running that much richer than the others?

 

[jhlarsen]

Just out of curiosity, how many kms on that motor and how many boosted?

2400km un boosted, ca 1000km boosted.

Why does the next cylinder over look so different? Was that bad hole somehow running that much richer than the others?

I did ride it down from the mountain after the valve vent to sh...
so i think that's why it looks like that.

 

[rxrider]

not likely, no compression, no combusiton, no carbon build up, would you mind showing us a few pics of your corresponding piston?

 

[jhlarsen]

here is some pic's.
anyone have a good ide on the cause behind the valve failure?

it's cyl nr.3

 

[Tarzan]

Ups...
Did you fix it?
What was wrong??

 

[rxrider]

Too tight valve clearance, causing compression leak and carbon buildup on the valve and valve guide until the valve jammed and got hit by the piston. One in many possible reasons. Was there any miscoloration on the above the valve.

BTW - are you up and running?