b18b - death of a timing belt
I was driving the car back from work last Monday afternoon, just cruising along with traffic - when suddenly i heard the sound of what sounded like thirty cracked out hamsters gnawing on my engine all at the same time...
the engine immediately seized up.
I had the little sucker towed home, and i rolled him into the garage where it awaited The Doctor for a diagnosis.
Upon inspection a few days later for the first time (last night), i immediately noticed that the timing belt had stripped itself out.
"Awh F*@k..." i said to myself - but i've been open to the idea of upgrading to stainless types for a little while now anyways. Called up Jim at Motorvations Motorsports to get the ball rolling on that, and had a talk with him about getting some head work done and larger valves installed. And agreed to bring the cylinder head to him tomorrow.
Tonight, when i took the valve cover off, i noticed this:
OH NOEZ!
Valvetrain configuration:
KMS dual valve springs
KMS titanium retainers
Crower 402 cams
Valve last specs are: .003 intake .005 exhaust (stock)
My questions are these: is this issue connected with the timing belt failing, or is this a separate issue that i need to address? What can cause the cam caps to crack like that? Now that i think about it, is it possible that the cams are bottoming out the valve springs at higher RPMs (since the lash is so close) and causing breakage?
And lastly: is there any type of machine work necessary when installing new cam caps on a head like this in order to match the two journal halves?
Update:
thanks to Barefoot for the answers.
After many distractions this evening (texts, laughing at Avatar wannabees, providing tech support for a client) - i finally got the cylinder head off, and almost had a stroke when i looked at the valves. Yeah, i've seen some bent valves before - bla bla bla...
but this kinda takes the cake:
all of the exhaust valves have visible damage:
and there are seriously visible valve strikes on the pistons:
Saturday afternoon update
Just got back from Motorvations, while i was there i informed Jim that most of the cam caps had been destroyed - he then told me how the heads were actually made at the factory, and suggested that perhaps it'd be a better idea to get a junked head with intact caps. (i wholly agreed)
Then we dismantled the head to remove the springs, retainers, and valves. A lot of the valves were bent in the actual stem, and we had to use a hammer+extension to push them out of the valve guides. Which means that the valve guides were probably toast anyways and needed to be replaced. Another reason to just start over with a new head.
This is the damage to the exhaust valves:
I'm surprised that the head did not snap off of this one and destroy the combustion chamber. Whoever "TAE" is, they make one heck of a valve:
I plan on updating this thread as things happen - so check back. But that's it for now, more later!
-jonathan
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Originally Posted by Da_unknown
