So, first off... how's it hanging everyone?



Timing belt broke the other day while accelerating onto highway. I would have thought that there would be loud noises if pistons and valves made contact (it just died, no noise), but I just installed a new timing belt and the motor won't start. Pretty sure I did it correctly, it's my second time doing it now and the other one lasted for roughly 63k miles before breaking.



Even though I didn't hear anything, it also seems logically impossible that pistons and valves did not make contact. I was accelerating (though not quickly at all) when it happened, and I know we have interference engines.



Anyone have experience with this? I know Patreezy's DIY from forever ago resulted in either pistons or valves messed up. Here's hoping I got off the hook, but I'm starting to doubt it.

 

Time to shop for a new motor

 

Yeah I just advanced and retarded timing by about 7 degrees as a last ditch effort and nothing. Time to take the head off, hopefully the pistons are fine.

 

More than likely bent some valves.

 

I have all 16 valves out of a head that had like ~50k miles on them if you need them. Jus let me know. But sorry to hear though.

 

You made contact, no doubt about it. Depending on how bad, you can probably salvage the pistons and grind down the contact marks to a smooth surface. Pull the head and check it out. The valves and valve spring assembly however will more than likely need to be replaced with new, even if you can turn the motor by hand. Maybe just get a whole new cyl head, might be cheaper. I know I've got spare empty to fully assembled ones that I'm going to be posting up for sale for less than cost of parts.



As for my DIY, I had an issue with the threads in the cyl head that the bolt that secures tensioner pulley goes into, ended up trying to get by without fixing it 100% which resulted in losing tensioner pulley tension on timing belt after replacing it. It resulted in needing to replace cyl head with all new. I did however end up running the motor with the knicked pistons with no problem.



Either way you go about it, you'll need all new valve assembly and possibly new pistons.



I was also surprised by the complete lack of noise.

 

Also have (2) beta motor (& a transmission), if you're interested in just swapping for all new.

 

So intake valves definitely hit on the number four piston. Piston just has slight marks on it, should be fine. Other than that everything looks fine. I'll let you know spoolinshark, would you be willing to break up the set?

 

They almost always need replacement in sets of four (two cylinders worth). If four's bent one's bent IIRC. You might need a dial gauge to tell if they're bent, but you'd be the luckiest person ever to only need 2 valves. My parts car had two visibly bent, two I needed to measure, and four well within 0.0002" of dead straight.



Lack of noise: the thing works by controlling baby explosions, and you missed a "tink" in there. No big surprise in retrospect.

 

In regard to that, there looked to be zero marks on either valves or piston on number one cylinder, and there was a ton of carbon buildup for it to knock off if it did contact. Also, don't one and four alternate exhaust and intake cycles, so that the much smaller exhaust valves were open on the #1 and maybe missed the piston? I'll definitely check everything again.



Also, I thought it would at least start and attempt to stay running down only one cylinder. That was pure speculation, but maybe there is something else bent up a little bit.



This is a pain in the ass, never letting timing belts get anywhere near the end of their life again.