the other night my timing belt broke, and I tried to start it a few times before I realized it was the timing belt. I have an internally stock LS at stock timing. what are the chances my valves are bent?

 

pretty good chance. The higher the revs the more likely.

 

You could always put on a new timing belt and see how it runs.......

 

how many miles did you have???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by miketegra &raquo;</TD></TR><TR><TD CLASS="quote">You could always put on a new timing belt and see how it runs.......</TD></TR></TABLE>

Doubt it!!!! think about it your belt snapped and every thing kept turning,... cams, crank,............................ chances are a the pistons could have hit some valves THATS NOT GOOD , open that sucker up and see what all screwed up

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dased530 &raquo;</TD></TR><TR><TD CLASS="quote">

Doubt it!!!! think about it your belt snapped and every thing kept turning,... cams, crank,............................ chances are a the pistons could have hit some valves THATS NOT GOOD , open that sucker up and see what all screwed up </TD></TR></TABLE>

yea I figured that, but it snapped as I was crusing at like 2500rpm's so maybe I got lucky. It had 125k and I was TOLD it was replaced 2 90k.......

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dased530 &raquo;</TD></TR><TR><TD CLASS="quote">

Doubt it!!!! think about it your belt snapped and every thing kept turning,... cams, crank,............................ chances are a the pistons could have hit some valves THATS NOT GOOD , open that sucker up and see what all screwed up </TD></TR></TABLE>

if the belt snapped, then the cams stopped spining, and thats the bad part, since its an interferance motor and then the belt most likely snapped where the vlaves were open in one of the cylinders, and then the pistons smakced the valves. you should do a compression test to see how things are, or a leak down test. you could pull the valve cover off, and then rotate the cams and see if everything looks ok, then check the compression, don't foget to make sure the valves are closed.

 

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

if the belt snapped, then the cams stopped spining, and thats the bad part, since its an interferance motor and then the belt most likely snapped where the vlaves were open in one of the cylinders, and then the pistons smakced the valves. you should do a compression test to see how things are, or a leak down test. you could pull the valve cover off, and then rotate the cams and see if everything looks ok, then check the compression, don't foget to make sure the valves are closed.</TD></TR></TABLE>

i know what happens when the belt snaps, Im just wondering how much valve clearance an LS has. also the cams are REALLY hard to turn, hell they really dont turn. I think its time for a new longblock....

 

Well, it was assumed that the valves would be checked for damage once the top end was opened up......I mean, once you are at the timing belt, you just need to remove the cams, intake, and exhaust to get the head off.
I should have said:
Take off the cylinder head (including cams, timing belt and all the other crap), inspect valves and pistons for damage, and if ok, throw on a new timing belt and call it a day. My bet is that if you didnt hear any nasty noises, your engine is ok.
don't assume the worst......

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dased530 &raquo;</TD></TR><TR><TD CLASS="quote">

Doubt it!!!! think about it your belt snapped and every thing kept turning,... cams, crank,............................ chances are a the pistons could have hit some valves THATS NOT GOOD , open that sucker up and see what all screwed up </TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sukebei Oni &raquo;</TD></TR><TR><TD CLASS="quote">
if the belt snapped, then the cams stopped spining, .</TD></TR></TABLE>

not at that same exact moment

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dased530 &raquo;</TD></TR><TR><TD CLASS="quote">

not at that same exact moment </TD></TR></TABLE>

they probably did since the cams are near impossible to move by hand. they definately wered spinning freely.

 

so what if the cams were on a part that the valves were open? then they hit.

 

same thing happened to me. my guess is if you didnt hear anything, youre probably ok. my valves were fine.
i thought the b18b was noninterference? do the circular cutouts on the pistons mean anything?

 

My timing belt broke at idle. Put a new belt on and it fired right up. You'll just have to wait and see.

 

same thing happened to me... at about 140K I was in neutral about to go down to 2nd to go around a corner, downshifted, got on the gas, and.... nothing. The belt snapped while I was in neutral at idle speed. No damage

 

...my friend's B18A lost a timing belt and there wasn't any damage. Apparently it's a non-interference design, so it would be safe to say the B18B likely be as well. A B18C, however, would not survive this...

 

my friends b18b broke its belt on start up and ruined the head! just depends on where the pistons r!!!!!!!!!!!!!!!!!!!!!!!1

 

You may be ok here... gonna have to get her running again and see how she feels though to make sure.