[Mike]

I have a problem with my timing chain. It seems that after I put both cams, and crank at TDC then turn my car on the colored links that are used to line everything up no longer are set at TDC when I set the engine their. The crank will be a few degrees advanced while both cams still line up together correctly.

I'm not totally sure what the deal is, but no matter how many times I reset the colored links to TDC with both cams and crank the same problem reoccurs.

I was thinking that maybe my autotensioner is bad, and I might need to replace it. Any ideas from people on here?

 

[TeamPacman]

Every time you put new cams in, you need a new autotensioner...

 

[Rubber Chicken]

If you align the special links with the marks on the cams, then turn the engine over, the marks will not align every time cylinder #1 is at TDC. You need to keep turning the engine until the bottom link is on the mark on the crank sprocket, which you can't see unless you remove the front cover.

Here's what to do when changing cams if you to be 100% sure you have the cam timing correct:

1. Turn the engine over by hand until the special links are aligned to the marks on the cams. This takes anywhere from 1 to 100 engine revolutions. After a while you can see a pattern of the links moving, which I think was every 6 or 8 engine revolutions. Take out the spark plugs to make it easier. Put the engine to TDC using a rod on cylinder #1, and check that the marks on the cam sprockets all line up. Take a photo with a digital camera for reference.
2. Remove the steel cover over the tensioner.
3. Put some pressure on the chain guide so that the little cam on the tensioner moves so that the holes line up, then put a pin in the tensioner to lock it. I use a filed down allen as a pin.
4. Lock wire the front of the timing chain making sure that you can still remove the cam sprocket. I use safety wire wrapped around the chain and chain guide.
5. Use something to tension the back of the timing chain and remove the tensioner (I use welding wire). The goal is not to let the chain slip on the crank sprocket.
6. Lock wire the chain so that it cannot slip down, while allowing the chain guide to pivot to give some slack in the chain over the cam sprokets. This is the most critical part. Use multiple pieces of wire.
7. Remove the cam caps and remove the cams. You will need to manipulate one cam at a time a lot, but they will come up.
8. Swap cams or whatever you're going to do. Don't forget to put the correct sensor wheel on the correct cam (they are marked IN or EX).
9. Put the cams back in, install the cam caps, put the chain over the cam sprockets so that the special link matches the marks. Take care not to turn the engine over nor move the chain.
10. Take up tension on the chain with the rear guide and install the tensioner. Remove the pin to release the tensioner.
11. Check that the marks on the cam sprockets line up horizonally. Refer to photo if necessary.
12. Remember to set valve lash (between the valve and rocker, not the roller and cam!).
13. Check everything looks OK, and you're done.

I know the whole process of keeping the chain on the crank sprocket is a pain, but if you do it this way then you can be almost 100% sure you have the correct cam timing.

If the chain does come off the crank sprocket, then all is not lost. Keep going and install the cams so that the horizontal marks line up. Once done give the engine a couple of turns, find TDC using a rod on the piston, and then check the marks on the cam sprockets look good. Use a ruler across them if there is any doubt.

 

[Administrator]

Wow... I need to read this post a few times. Thank you Derek.

 

[Mike]

If you align the special links with the marks on the cams, then turn the engine over, the marks will not align every time cylinder #1 is at TDC. You need to keep turning the engine until the bottom link is on the mark on the crank sprocket, which you can't see unless you remove the front cover.

Here's what to do when changing cams if you to be 100% sure you have the cam timing correct:

1. Turn the engine over by hand until the special links are aligned to the marks on the cams. This takes anywhere from 1 to 100 engine revolutions. After a while you can see a pattern of the links moving, which I think was every 6 or 8 engine revolutions. Take out the spark plugs to make it easier. Put the engine to TDC using a rod on cylinder #1, and check that the marks on the cam sprockets all line up. Take a photo with a digital camera for reference.
2. Remove the steel cover over the tensioner.
3. Put some pressure on the chain guide so that the little cam on the tensioner moves so that the holes line up, then put a pin in the tensioner to lock it. I use a filed down allen as a pin.
4. Lock wire the front of the timing chain making sure that you can still remove the cam sprocket. I use safety wire wrapped around the chain and chain guide.
5. Use something to tension the back of the timing chain and remove the tensioner (I use welding wire). The goal is not to let the chain slip on the crank sprocket.
6. Lock wire the chain so that it cannot slip down, while allowing the chain guide to pivot to give some slack in the chain over the cam sprokets. This is the most critical part. Use multiple pieces of wire.
7. Remove the cam caps and remove the cams. You will need to manipulate one cam at a time a lot, but they will come up.
8. Swap cams or whatever you're going to do. Don't forget to put the correct sensor wheel on the correct cam (they are marked IN or EX).
9. Put the cams back in, install the cam caps, put the chain over the cam sprockets so that the special link matches the marks. Take care not to turn the engine over nor move the chain.
10. Take up tension on the chain with the rear guide and install the tensioner. Remove the pin to release the tensioner.
11. Check that the marks on the cam sprockets line up horizonally. Refer to photo if necessary.
12. Remember to set valve lash (between the valve and rocker, not the roller and cam!).
13. Check everything looks OK, and you're done.

I know the whole process of keeping the chain on the crank sprocket is a pain, but if you do it this way then you can be almost 100% sure you have the correct cam timing.

If the chain does come off the crank sprocket, then all is not lost. Keep going and install the cams so that the horizontal marks line up. Once done give the engine a couple of turns, find TDC using a rod on the piston, and then check the marks on the cam sprockets look good. Use a ruler across them if there is any doubt.

Thanks for the help, but that isn't quite the problem.

I did the A2 head swap on my A3 block. After getting everything put together the engine is knocking (registered through K Pro). In an effort to try and figure out what is wrong, i'm wondering if maybe the timing is off. Although, after taking it all apart again, including the chain case cover I can assure that it is not.

We're still currently trying to find out why its knocking.

 

[typesfanatik]

with timing off you can really damage your engine bad right


we are doing my itr install this weekend and im gettin all the research in i can

 

[chameleon]

wow, who's the idiot that said you need a new auto tensioner.. geez. if you remove the tensioner and then use some pliers to squish it down, just hold the little orange arm down which will let you compress it, once compressed all the way just pull the little arm up so it aligns with the little pin hole which you can slip in a really small alan key to hold it in place. so once you put the timing chain on and alingned with the colored key marks you have to tighten it very well so put back the tensioner without letting the chain slip, once its on remove the key, and you can push the chain holder by hand ( the one that supports the left side of the chain) until its tight, spin the crank around to make sure its tight and you are set. of course to line up the chain marks the cams have to be both in "up" and the crank gear has to be aligned with the down arrow on the block with the dot on the gear.

 

[nikos]

A new tensioner is a good idea. Someone on here, changed cams and head internals and used the old tensioner.... After a few dyno runs and making 270whp.... the chain jumped due to bad tensioner and his block took a crap. So, to be safe I would spent $50 for a new tensioner.

 

[chameleon]

that doesnt make any sense really, i had a jdm tensioner and the tsx one, both are identical and work in the same exact way its a little lock mechanism, it just doesnt occur to me how they can go back. especially since the tsx one i have has about 1 mile of use on it. there is no way honda is going to design a motor 10x better than a B but yet fuck up a tensioner mechanism. timing chain is tricky but once you study how its setup man its cake. i even have the helms for the RSX S and no where on it does it say tensioner should be replaced, anywhere in the uninstall directions.

 

[suckafree]

hmm.. i think the point is, why chance it>? a $50 part....or a $2-5k part...change the tensioner..or dont... up to you but i would

 

[non vtec]

the tensioner is run by oil pressure, it is possible that if its low on oil pressure that in the middle of an adjustment it will smooth the locking pin off the end of the tensioner and slip. I know this because its what happened to mine. wwe made deeper grooves in my tensioner to help it lock better and at this stage it has lasted. But we are going to make a solid mechanical tensioner like a B-series one or a limiter to protect the chain if it does fail... I would prefer to have to replace a chain guard every season during a rebuild than kill another motor..

 

[98specR]

down by the river

 

[typer558]

see this link!