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Discussion Starter · #1 · (Edited)
I have a k24z3 in a 2.4L '08 Honda Accord and I am fixing a stretched timing chain. Unfortunately, in my stupidity, I lost timing between crank and camshafts... chain was so stretched it slipped by accident over crank when I was doing something. Can I re-time the engine by the following procedure?

1. Remove the timing cover and chain
2. Set the pistons at their middle point (check piston height with wooden dowel down spark plug hole) by rotating the crank
3. Rotating the cams separately to place cams back into TDC position without damaging the valves
4. Rotate crank back into TDC position

I am assuming that the pistons at their midpoint will not interfere with the valves? Also I assume I can I rotate the cams separately or will they interfere with each other?

Thanks so much for the support.

Rob
 

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You're going to replace the chain and tensioner as well, right?

Remove spark plugs, this will make the crank easier to turn. Pistons won't hit valves if they're sitting in the middle. All four pistons are at the middle at two points, go to whichever one is closest to where it sits currently. Turn the crank over slowly. If you feel any resistance, go the other way.
 

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Discussion Starter · #3 · (Edited)
You're going to replace the chain and tensioner as well, right?

Remove spark plugs, this will make the crank easier to turn. Pistons won't hit valves if they're sitting in the middle. All four pistons are at the middle at two points, go to whichever one is closest to where it sits currently. Turn the crank over slowly. If you feel any resistance, go the other way.
Thanks Brotatochip - definitely swapping chain and tensioners. Pistons are currently in the middle position. With that set in place, how do you suggest I rotate the cams to get them back to TDC? They are now both in time relative to each other (chain on) but when I remove the chain do I need to rotate them simultaneously to get back to TDC or can I move them independently without causing interference (valve on valve.. if this is even possible)? Is CCW rotation on cams okay or is CW always required for this step of the process?
 

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If they are currently in time they will likely move slightly when the chain comes off, not much though. There are pins you can get to lock the cams in place but I have never had to use one. It has been a while but I believe there is a spot in the middle of the camshaft you can get a large wrench on (or crescent wrench). There is no harm moving the camshafts CW or CCW separately. Again, you shouldn't have to move them much at all.

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Discussion Starter · #5 · (Edited)
Okay makes sense, I have the little Honda camshaft lock tool to lock the cams in place once I get them there. Unfortunately, at the moment the cams are pretty far off from TDC (cam TDC marks circled in red):
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And the crank is in this position - TDC mark is 90 deg CW to arrow on timing cover: (white mark circled in red)
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So just to confirm, based on the pictures above and your very much appreciated expertise I'll first:
1. remove crankshaft pulley (special crank holder wrench tool should be delivered in 1 hour..)
2. remove timing cover and then tensioner/chain
3. confirm pistons are at the midpoint by checking the crankshaft is at the position shown above
4. rotate camshafts independently back to TDC (i.e.first rotate left (rear) cam ~90 deg CCW based on pic and then right (front) cam approx the same distance CCW)
5. finally can I rotate the crankshaft 90 deg CCW to align the white marks on the crank pulley wheel to the arrow on the timing cover or should I rotate it CW as the engine runs? Problem is, If I rotate it CW to put cylinder #1 at TDC, then the white mark on the crank pulley will be misaligned by 180deg to the timing cover arrow... or will all the valves be closed when cams are TDC and I can rotate the crank freely 270deg CW back to TDC? pardon my ignorance.
 

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Unfortunately, at the moment the cams are pretty far off from TDC
My mistake. I misread your original post.

You've got it. If crank is ~90 degrees clockwise off of TDC, pistons should be in the middle. Remove the chain, rotate cams back and lock in place with your tool. Rotate crank back CCW to TDC. If you rotate 270 degrees to TDC I believe they will hit valves. If you only rotate 90 degrees CW you are correct and cam/crank timing will be 180 degrees off. That obviously won't work.

There is no harm rotating cams/crank CCW while no chain is on (as long as you're not hitting valves). Once the chain and tensioner are on, only rotate CW. Once it's set, rotate the crank CW a few times and then check timing marks. If it's an OEM timing chain with the colored links to help set timing don't worry when they don't match up any more. Only the marks on the block matter once at that point. If the marks still line up, you're good to reassemble everything.
 

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Discussion Starter · #7 ·
All of the replacement parts are OEM (mailman just arrived) so the colored links on the chain should help with checking for proper installation. This is my first time ever digging into the engine so I cannot thank you enough for your advice. You really helped relieve my nerves after I screwed up the timing this morning... Thank you for that and I will be back with an update! Time to get to work.
 

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No problem, glad I can help. I remember my first timing job, belt change on a D series. Took me every bit of 12 hours over two days. Now, they're a piece of cake ;)
 

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Discussion Starter · #9 ·
Timing chain installed! - Took 7 hours from removing crank pulley (pain in the a**) to install of new vtc actuator, chain tensioner and guides. Exactly as described above. Rotating the crank after install was like butter. Will save the rest for another day. Had a bit too much fun doing that, maybe I should start a timing chain shop :D Thanks agian.

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Glad to hear. Nice work.

If you plan on doing more timing belts/chains and want to make your life significantly easier, buy one of these. Stick it on a big impact and it takes the crankshaft pulley bolt right off. I have a big Milwaukee 1/2" impact and with this socket it takes it off in like three hits, so easy. Much better than digging out the big 3/4" breaker bar, pulley holder, cheater pipe, etc.

https://www.amazon.com/Lisle-77080-Harmonic-Balancer-Socket/dp/B00RGNCV1U/ref=sr_1_2?crid=AYBJ0DQE1S21&keywords=Lisle+77080&qid=1659964571&sprefix=lisle+77080,aps,126&sr=8-2
 

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Discussion Starter · #11 ·
Thanks for the rec, I had a 1/2” harbor freight impact and a 19mm socket (no extensions) that was slightly smaller (lower moment of inertia) than the one you sent and it wouldn’t budge. Heat and a 6ft extension to breaker bar and it cracked. Btw the engine just started up. Brilliant. Again, thank you.
 
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