timing belt broke - Honda Prelude Forum

maxlude240sx · 10-26-2007, 03:54 PM

need some help my timing belt broke on my way to work, my question is am i going to have to redo the head? i have been told that i probably bent a valve or two.any advice you could give me would be greatly appreciated

petern101 · 10-26-2007, 04:12 PM

^pretty much. mine broke and i had a few valves bent. so i bought a jdm h22.

what you need to do is pull the head. inspect (i am 90% sure you will find damage)

two options: 1. remachine head w/new valves / other new parts 2. buy another motor swap in

either way you should replace the waterpump / other maintenance stuff. might be a chance to upgrade valves, 3 angle job, etc

G_Loc · 10-27-2007, 12:01 PM

Depends. Do you have an F22, H22 or H23?

suckmykiss4819 · 10-27-2007, 08:30 PM

but a used head for cheap or but an h22a head/block. your bottom end isnt damaged. it is more expensive to remachine the head for new valves..... so id buy a whole new head, it will save you money and time

TruNinja619 · 10-29-2007, 08:56 PM

Quote:

Originally Posted by suckmykiss4819

but a used head for cheap or but an h22a head/block. your bottom end isnt damaged. it is more expensive to remachine the head for new valves..... so id buy a whole new head, it will save you money and time

how do you know if his bottom end is not damaged?

petern101 · 10-29-2007, 10:16 PM

Quote:

Originally Posted by TruNinja619

how do you know if his bottom end is not damaged?

there's a good chance it isn't. mine was visually good..

but still, i would scrape the whole thing for worry of problems later on

plus you can find h22's for a decent price nowadays. worth the upgrade imo for hp

good bang for your buck

TruNinja619 · 10-30-2007, 12:07 AM

Quote:

Originally Posted by petern101

there's a good chance it isn't. mine was visually good..

but still, i would scrape the whole thing for worry of problems later on

plus you can find h22's for a decent price nowadays. worth the upgrade imo for hp

good bang for your buck

reason why i said that is b/c i snaped my timing belt on the freeway and ended up having to replace 2 piston heads along w/ doing a valve job..

petern101 · 10-30-2007, 09:50 AM

i snapped mine going 50mph but just ruined the head. but its wierd because h-series motors are non interference motors while not in vtec. but pretty much everyone that has snapped a timing belt has ruined their head (or more)

i guess its just wierd like that

MNludeDVR · 10-31-2007, 07:52 AM

I snapped a timing belt on the freeway and it didn't do any damage at all. Compression check was perfect on all cylinders and once I threw a new belt on, it was perfect.

firestorm · 11-21-2007, 02:10 PM

yeah i broke my timeing belt at 60mph no problem with the bottom end but head was shot

kellyk75 · 11-21-2007, 04:10 PM

Quote:

Originally Posted by petern101

h-series motors are non interference motors while not in vtec.

How does that work? Please explain.

noopie · 11-21-2007, 05:47 PM

Quote:

Originally Posted by kellyk75

How does that work? Please explain.

i really dont know if thats true. if that was true then ppl wouldn't hit the valves at rpm below 5k, which we all know is not the case.

this actually happened to me recently @ ~2k - compression and leakdown were fine. new belt is on and the prelude is running great.

pretty much i learned that when this happens, what needs to be done is
1) compression test - if that looks okay then ur valves are prob fine. if compression is lower in some cylinders, this is suspicious for

, you'll need to go to:
2) leakdown test

if those diagnostics check out then put a new belt on and see how things run.

kellyk75 · 11-22-2007, 08:10 AM

It isn't true. Simply put, the cams are attached to the crank via the timing belt. This keeps the valves opening as the pistons reach a certain point on the down stroke. VTEC changes when the valves open on that stroke to maximize power at higher RPM's. They don't open the valves further, just the timing (when opened and how long). When the timing belt breaks, the pistons are moving independently of the valves. There is no control over when the valves open and piston position....... therefore, collision & bent valves. My logic is that there is more momentum in the lower end of the engine, so the valves/cams will stop much quicker than the pistons/crank which is why sometimes only some valves are bent instead of most.

Again, this is just my understanding.