Well.....what happens as a result? What breaks?

 

Umm, I believe that you lose the control of you head, and end up with pistons meeting valves. If, your really unlucky, camshafts break

 

Usually what happens is that the cams stop rotating since their power source (the timing belt and crankshaft) is no longer able to spin them. So, the valves are in roughly whatever position they were in when the belt broke. Generally, one or more valves are open.

The crankshaft continues to spin due to inertia and since the camshaft(s) and crankshaft are no longer in sync, the pistons smack the valves and either bend them or break them.

Sonny

 

you also have a possibility of breaking your pistons

 

yea basically pistons meet valves. however, on non interference engines, this will not happen but i believe that honda engines are interference engines.

 

d15b timing belt snaped at 70mph... suprisingly there was no damage.

 

It also depends on what you were doing to the motor at the time the belt snapped, for instance, if you were flooring it and revving past 7k rpms, you will do some serious damage to the engine. But if you were rolling on the freeway at like 3k rpms and not pushing it, theres some good chance you will not do any damage. I've seen some snap and do tons of damge, and some do not do any damage.

Damages could be, bending valves, damging the valve guides, dome, piston head, even possibly cracking the piston depending on the conditions. The damage is unpredictiable.

 

i heard inlinefour say that they the cams automaticly turn to a point where all the valves are closed when the timing belt breaks...but at high RPM say bye to everything....

 

your jack

 

valves and pistons have metal intercourse!!!!!!
most newer engines are interference fit engines this means that when a timing belt breaks the valves and pistons can mate . on older hondas 80s and older thease were not interference fit and if a belt broke even at higher rpm no damage would occur

 

well i got lucky, was on the highway, going about 70, in 5th gear, low rpms, lost all power, let off gas, put it in neutral, i knew immediately what it was, coasted off the highway, timing belt was hanging off. Put a new belt on, waterpump, main seal, it started and ran fine, had to adjust the valves though. I got lucky i guess, 93 si hatch.

 

basically ur f*ed