sinister357

what i mean is if the timing belt breaks on a gsr, will i be sure to have bent valves? the reason i ask is because i've heard the same story on the d16z6 (sohc vtec) but when mine broke, all was fine - so those aren't interference engine. i've read several manuals and they all say "possible", so i'm still not sure about the b18c1. it either is or it isn't. has anyone broken their timing belt and lived to tell about it?

EDIT: interference engine are engines that have their pistons share the same space as the valves - just not at the same time during the cycle. which brings me to the point of valve reliefs on pistons - are they there for the purpose of avoiding each other in case something does happen (belt breaks) because when the pistons are at the top, non of the valves shouldn't be fully opened anyway (if at all) to be requiring the reliefs. any second thoughts? sorry, i'm a newbie and still limited to 5 post a day - wish i could at least "bump"




Modified by sinister357 at 5:50 PM 9/19/2004

m R g S r

It's not set in stone that your valves will bend if the timing belt breaks, there is just a very strong chance

PissedoffGS-R

If you try an understand what the timing belt does in relation to keeping the valves in sync with the pistions via the cam gear/s and crank pulley. When that belt gos theres nothing to keep the valves from trying to open when the pistons are on an up stroke, witch would lead to the pistion hitting the open valve/s and geting crunched, resuling in either just the bent valve or the bent valve and a scored piston or both along with scored cylinder walls.

sinister357

anyone else with any opinion or past experience with broken timing belt? i'm hoping to find a definite answer to this question. thanks

JDM civic master

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister357 &raquo;</TD></TR><TR><TD CLASS="quote">anyone else with any opinion or past experience with broken timing belt? i'm hoping to find a definite answer to this question. thanks</TD></TR></TABLE>

There is no definite answer, sometimes it causes a lot of damage, sometimes it doesnt cause damage.

sinister357

but the chance of all the valves being closed on all cylinders at the same time is, well it doesn't happen. so when the belt breaks, somethings gotta give, unless there are sufficient clearance designed into the motor already as in my d16z6. there shouldn't be a "maybe".

JimBlake

Why can't it be a 'maybe'?

Have you ever turned a camshaft when the belt is off? The valve springs make it sorta snap into certain positions. If the belt brakes it's gonna come to a stop at one of those positions where most valves are closed, and a couple are nearly closed. Even the ones that are slightly open won't get hit, with stock internals of most engines. (Maybe not true for B18C5???)

A valve has to be pretty far open in order to get hit. So it all comes down to dumb luck whether any valves get hit WHILE the cam is coasting to a stop.

High-lift cams, or pistons that raise CR, or milling the head, etc... Those things that raise CR, will make it more likely to get hit because there's more interference.

PatrickGSR94

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister357 &raquo;</TD></TR><TR><TD CLASS="quote">but the chance of all the valves being closed on all cylinders at the same time is, well it doesn't happen. so when the belt breaks, somethings gotta give, unless there are sufficient clearance designed into the motor already as in my d16z6. there shouldn't be a "maybe". </TD></TR></TABLE>

You got lucky. All D-series and B-series engine are of the interference type as far as I know. I don't know of any non-interference Honda engines, there may be some but I don't know of them.

I know that Toyota engines are non-interference. If the timing belt breaks your car just dies on the side of the road, but there's no permanent damage.

sinister357

as i have said, my belt broke on my d16z6 too and nothing happened. those i'm sure are not interference engine. can someone prove me wrong on that? when putting the belt back on, i was playing with the crank and cam gear - spinning them all around which ever way - and it still came out ok. anyone broken their b series timing belt yet? i'd like to hear your story.


Modified by sinister357 at 1:26 AM 9/22/2004

PatrickGSR94

iTrader: (1)

B-series engines will definitely destroy themselves if the t-belt breaks. I know that for a fact 100%. Are you sure you didn't just turn it off immediately when it broke and maybe got lucky? When we were doing my friend's SOHC VTEC swap in his DX Civic, I'm pretty sure the pistons and valves would touch each other at some point in the rotation before we installed the timing belt.