Here is my scenario. I was at a practice day with my road race car (2000 Civic with LS-vtec) and the motor stopped while I was rounding a corner. There was a power loss of about 1-2 seconds followed by a loud noise (like something grinding to a halt) and the engine stopped. I coasted into the paddocks.

When we tried the starter, there was an interesting sound.. it felt like the engine was turning over but there was no "chug-chug-chug" sound. We checked the compression and there was none. Long story short, it looks like the alternator belt came off and got caught up in the the timing belt, throwing the timing off by several teeth. When we removed the valve cover, all the valves were loose and I was told that they must have hit the pistons and all bent.

Now the car is parked at the race shop for the weekend. They will only have time to pull the head to look at the damage Monday. <U>I have a race next weekend and I need to know what the chances are that I can just buy new valves and have them installed (in which case I will move my *** to find some valves this weekend) or whether it is likely that my pistons and/or other parts are toast.</U> If they are, I will not repair the engine before next race for lack of time and mainly funds. However, if it is likely I can just change the valves, I will buy whatever I can find in the next couple of days locally. Thanks in advance for any input.

 

fi you broke off the end of the valve you might have destroyed the bottom end

if you bent the exhaust valves...more than likely your guides are also broke....

 

Early on, I installed the timing belt way too tight--and probably didn't tighten the tensioner bolt enough, and the belt slipped at about 8000 rpm-- I bent every single valve and broke a few guides--the pistons though, just had little tiny divots in them and after getting my head re-done the motor ran perfectly. My experience.

 

chances are you are fawked! sorry bro... interference motors suck

but you wont know until you take it apart

 

it happened to me 2 months ago. put a hole the size of your finger through the 3rd piston, and broke the head of the valve off and jammed it into the head. your fucked. it gave me a reason to build a motor.

 

This is what it looks like:




That was my GS-R. It happened to me

 

Well, those are pretty catastrophic failures. In regards to your setup alot of factors come into play. If the pistons are just nic'd then you can take the high spots off of them a get it back on the road. If you bent one enough to damage a valve seat then the head will have to be reworked and most likely it will have to be for the guides anyway. my advice to you would be to source a head now if you want to be on the track in time. I believe there is one in the classifieds for 300.00 that has been up for some time. Sorry to hear about the bad luck.

 

or u might get luck the same thing happened to me and i pulled my head off and there was no damage at all i don't know if having forged pistons and ss valves have anything to do with it tho

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PogKai &raquo;</TD></TR><TR><TD CLASS="quote">This is what it looks like:




That was my GS-R. It happened to me </TD></TR></TABLE>


this is exactly what happened to me 2 weeks ago, if i were to post pics you would think the pics above and my pics were the same. ive bent my vavles like2 times and the 3rd time it ruined the head and pistons. this was all cause i used bigger cams on stock pistons

 

dammm...that is too crazy!

 

Pictures like these scare the **** out of me and turn my stomach.

 

Really scary indeed. . .thats why claying is so important.

 

i had a b16 that did that once... cause the retainer snapped cause of misshifting... HEHE

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RudeBwaiSi &raquo;</TD></TR><TR><TD CLASS="quote">Really scary indeed. . .thats why claying is so important.</TD></TR></TABLE>


How is claying going to help in this situation when the timing got all mashed up due to a rogue alternator belt?

As dcb16 stated, it's an interferance motor, anytime the timing belt snaps or timing gets all screwed up like in this situation, you're likely gonna have the valves kissing pistons.

Civic44, pull the head and report back....hopefully it can be repaired before your next race, but from the way you describe things.... hold on to your heart.... and wallet.

 

The only way to tell is to pull the head.

Also I have no idea how claying the motor wouldof help prevent this failure

 

OK, the head has been pulled. All the valves are bent. There is damage to the seats. The pistons are OK. The valve guides are damaged. There is no time to properly replace the guides. He is proposing to change the valves and do a valve job. The car can be raced this weekend (biggest event of the season) and would see about 2 hours of track time. There are two risks:
1) The pistons seem to have hit the valves pretty hard and we don't know what condition the pins that connect the rods to the pistons are in after this contact. There is definitely no time to verify this before the race.
2) The valves will be running with cut-down guides. They are aftermarket valves and are supposed to be much stronger than stock. This is something that would have to be addressed sooner rather than later. That's a headgasket and a bunch of labour each time...

Anyway, I told them to fix it... what kind of risk am I taking here? Any opinions? Would shifting at 7800-8000 instead of 8200-8400 make any difference?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RagingAngel &raquo;</TD></TR><TR><TD CLASS="quote">
How is claying going to help in this situation when the timing got all mashed up due to a rogue alternator belt?
</TD></TR></TABLE>
Sorry didn't note that that was the reason.

 

I think it's a real tough call.

In my eyes you are running a time bomb because you have to "half ***" the job and that's completely understandable since it's the biggest event of the season.

You didn't mention what type of aftermarket valves you are going to run? Are they some of the many that are flat faced and offer a slight bump in compression too?

Shortshifting it will reduce the risk since you are running up to two hours and it's not like a 10-14second rip down the drag strip.

In the end, you have to ask yourself if you are prepared to build yourself something completely new if you experience a catostrophic failure.

 

This was what happened to mine last month AT THE DYNO:

 

i know im a year late but the head looks like a b16...
the combustion chambers arent square like the gsr..

 

Well hopefully if you're somewhat lucky this could happen:

Still seems to amaze me how the remainder of my intake valve conviently located itself on the adjacent exhaust valve. Here's the piston, hardly untouched, cylinder wall not blemished at all:

Filed and smoothed down the top of the piston afterwards, head was rebuilt free of charge with 16 brand new valves, and compression across the board is now 240 psi

 

Big *** Pics for Clarity . Mine resulted in lack of valve to valve clearance, but considering your timing belt jumped a few teeth it won't be the same scenario. Keep your fingers crossed though, ya never know until you pull the head

 

Well, I see this thread is back from the dead. It turns out the engine did not make it through that race weekend. A rod let go and the block was toast. I had to change blocks again and 4 more valves.

On the bright side, I managed to borrow a friend's car for the race and, starting from the back of the pack, I gained 10 positions to finigh 14th, so the weekend was not a write-off, although the engine was.