Recently, this happened to my ITR block w/ CTR pistons at the dyno while tuning:



Before the dyno, we were able to (1) check valve to valve clearance and (2) valve to piston clearance (w/ the new set of cams). After this happened, we checked the (3) bearing but it was still ok.


The reason for the new tuning at the dyno was my upgrade from Spoon cams to Crower 63403-2 and replaced my ITR valve spring and sk2 tit ret w/ a set by crower's.

I know my valve did fall off. But still guessing how it did happen...

 

improper timing belt tension, improper valve to piston clearance, or fatigued higher mileage valves.

 

shiit..One of my REV valves broke off @ the stem, it caused this same damage, I was @ about 3500-4000 on the freeway, I had about 2000 miles on the engine....I cannot explain why the valve broke the way it did...**** SS valves, im sticking with OE....

 

How did your retainers and keepers look? Still there I hope.

 

OUCH!

 

looks like one of the valve faces dropped clean off

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CompressionFed &raquo;</TD></TR><TR><TD CLASS="quote">How did your retainers and keepers look? Still there I hope.</TD></TR></TABLE>
The valve spring and retainers are still ok. Couldnt have been valvetrain failure...?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1.6i &raquo;</TD></TR><TR><TD CLASS="quote">shiit..One of my REV valves broke off @ the stem, it caused this same damage, I was @ about 3500-4000 on the freeway, I had about 2000 miles on the engine....I cannot explain why the valve broke the way it did...**** SS valves, im sticking with OE....</TD></TR></TABLE>
While "clay"-ing the valve to piston clearance, a couple of these valves bent when they rotated the crank. It didnt just happen once but twice on different occasions while measuring clearances. Is this suppose to happen with aftermarket valves? Lousy. I'm going OE with my next project.

 

ouch.

 

yowza

 

the same thing happened to me and i still dont no what happened

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by grenthang &raquo;</TD></TR><TR><TD CLASS="quote">the same thing happened to me and i still dont no what happened</TD></TR></TABLE>

you had stainless steel valves or stockers?

 

Seat concentricity?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rocket &raquo;</TD></TR><TR><TD CLASS="quote">Seat concentricity?</TD></TR></TABLE>

I have never heard this term before, please explain if you will!

 

Research valve seat concentricity and it's effect on the longivity of the valve.

 

I'm with Rocket on that. The same thing happened to my last setup, I had RM springs with Dynamic valves and after about 500 miles kaboom. My head looked like just missing a valve seat, it came completely out of the head. For mine I believe it was due to bad maching though, the valves were cut VERY thin but they assured me it'd be fine, heh WRONG. They also too A LOT off the seat that broke out. Never ever will I go back to that hack shop, the new setup is amazing compared to that ****.

 

Ah good post sir.

Bad concentrity will pound the seat loose and seats will fall out. Same effect as running slightly bent valves long enough to do the same.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1.6i &raquo;</TD></TR><TR><TD CLASS="quote">

you had stainless steel valves or stockers?</TD></TR></TABLE>

NEW stainless steel valves. They were just installed around 2,000 miles before this happened.

Rocket/PandaHatch, never heard of this before. Seems like thats what happened..
Great info! Thanks!