Broken Timing Belt - What Next?

[EatsHondas]

So I was planning on putting off the timing belt and misc cooling system maintenance until this summer when I had some free time on my hands. Let me tell you right now, if you ever catch yourself thinking like me, DON'T!

My timing belt snapped last week while I was idling at a stoplight. 300 miles from home. I kid you not, it was an absolute nightmare. I got lucky and found someone who towed it all the way back to my door for $600 exactly, but I still have a car that won't drive.

Right now the car is sitting on stands and partially torn down to get to the timing belt since I can only work on it over the weekends.

My question is this: should I put a timing belt (and all the related parts) on it and see if it will crank? The belt went at idle so I was thinking there could a be chance that there's no damage (extremely unlikely I suppose, but possible). Or should I go ahead and pull the head now without even bothering with the belt first? If I find any damage, the head is going out the window since there are plenty of B25's in my local junkyards.

Thoughts?

[ButtJuice]

I'm not well versed on this particular subject, but I'm sure I can tell you what the Pro's will suggest;

Don't bother praying while putting on a new belt. Take off the head and either repair it (valves, ect.) or put another known working one on.
When it comes to this shit, don't half ass or hope for the best, just do it the proper way.

GL man.

[EatsHondas]

I'm not well versed on this particular subject, but I'm sure I can tell you what the Pro's will suggest;

Don't bother praying while putting on a new belt. Take off the head and either repair it (valves, ect.) or put another known working one on.
When it comes to this shit, don't half ass or hope for the best, just do it the proper way.

GL man.

Yeah the more I think about it the more that makes sense. I remember thinking my car was in really good shape when I bought her 6 months ago, but I've found sooo many problems since then. Damn it.

[smerfs]

sounds like a perfect opportunity for an m5x/s5x swap!

My advice would be to just tear into the motor instead of the valves, I've yet to see a T-belt snap without doing any kind of damage.

[Cronopoulos]

M20's are interference motors meaning the pistons went on a date with your valves and they had buttsex lololol....

Takes 45 minutes or so to get the head off, I say make it a weekend venture and get her done! Although swaps are cool, i cant justify it at ~3-400 at most worth of work and a few hours of your time. Just my .02

[MR 325]

Even at idle you're likely to have 3-4 bent valves. Pull the head and have it rebuilt or replace it with another.

[jlevie]

As others have said, there is about zero chance that there aren't bent valves. The good news is that it happening at idle means that there is probably little if any other damage. Pull the head, tear it down and check for bent valves. Replace any that are bent, have the valves ground, the head surfaced, and install new seals. It may be necessary to replace the valve guides.

[EatsHondas]

As others have said, there is about zero chance that there aren't bent valves. The good news is that it happening at idle means that there is probably little if any other damage. Pull the head, tear it down and check for bent valves. Replace any that are bent, have the valves ground, the head surfaced, and install new seals. It may be necessary to replace the valve guides.

I think that's what's going to have to happen. Hopefully I can get the old head all the way off this weekend and start sourcing a new one. I'm a little intimidated though, the most internal engine work I've ever done on a car is adjusting the valves. Guess I'd better dive in.

[wilholl]

Mine broke while trying to start... cranking.
Can you guess what I found inside???

bent valves!!

[jlevie]

I think that's what's going to have to happen. Hopefully I can get the old head all the way off this weekend and start sourcing a new one. I'm a little intimidated though, the most internal engine work I've ever done on a car is adjusting the valves. Guess I'd better dive in.

Unless you find a lot more damage that I suspect that you will find, rebuilding the head you have will be the least expensive option. If you go with a used head, it will need everything except (perhaps) some new valves.

[South26]

Here is a post I made over on mye28.com about taking apart a m20 with a broken timing belt.

http://www.mye28.com/viewtopic.php?t=92474&highlight=

So hopefully you do not have the melted domes or the holes in the pistons.

Andy

[chance]

The machine work and new seals can add up pretty quick.

Getting the head off is pretty easy once you get all the crap out of the way. It didn't take long at all for me to get my first m42 torn down.

[EatsHondas]

Unless you find a lot more damage that I suspect that you will find, rebuilding the head you have will be the least expensive option. If you go with a used head, it will need everything except (perhaps) some new valves.

A rebuild would be nice... I was thinking I needed new eccentrics anyway since she still ticks after a valve adjustment. It looks like there's a automotive machine shop right down the street from my house, so I'll give them a call to see what they'd charge to look my head over. What kind of ballpark should I be expecting pricewise?

The machine work and new seals can add up pretty quick.

Getting the head off is pretty easy once you get all the crap out of the way. It didn't take long at all for me to get my first m42 torn down.

All the timing belt related stuff is out of the way, I won't be able to pull the head until later on. It shouldn't be that hard though... All the mess of wires, hoses, and connectors are on the intake side. I wanted to pull it with both manifolds still attached, but that's gonna be retardedly heavy.

The head shouldn't need any machining right? Never been overheated so I doubt it's warped, and if it's cracked it's f*cked.

[chance]

A rebuild would be nice... I was thinking I needed new eccentrics anyway since she still ticks after a valve adjustment. It looks like there's a automotive machine shop right down the street from my house, so I'll give them a call to see what they'd charge to look my head over. What kind of ballpark should I be expecting pricewise?



All the timing belt related stuff is out of the way, I won't be able to pull the head until later on. It shouldn't be that hard though... All the mess of wires, hoses, and connectors are on the intake side. I wanted to pull it with both manifolds still attached, but that's gonna be retardedly heavy.

The head shouldn't need any machining right? Never been overheated so I doubt it's warped, and if it's cracked it's f*cked.

If it bent the valves, I would probably replace the valve guides, as they may have been damaged. The actual surfacing of the head should be under 100 bucks, but lapping in the new valves and having the new valve guides installed might run you a few hundred more.

OR..... I helped Ryan pull his whole swap.. m50 with s52 head/cams, nice zf trans.. you know you want it

[jlevie]

A rebuild would be nice... I was thinking I needed new eccentrics anyway since she still ticks after a valve adjustment.

The eccentrics being worn won't cause ticking, but worn valve guides will.

All the timing belt related stuff is out of the way, I won't be able to pull the head until later on. It shouldn't be that hard though... All the mess of wires, hoses, and connectors are on the intake side. I wanted to pull it with both manifolds still attached, but that's gonna be retardedly heavy.

Pulling the head with manifolds attached will be a bear singled-handed unless you have a hoist.

The head shouldn't need any machining right? Never been overheated so I doubt it's warped, and if it's cracked it's f*cked.

In my experience, a used head always has some warp so I routinely have a minimal surfacing cut done.