View Full Version : I think I've wrecked a new cam chain :(
erik
4th December 2005, 13:36
Crap! I think I've stuffed a new cam chain!
The cam chain came as a continuous chain that had to be split. I didn't think to grind the head of the pin off before pushing it through to split the chain :doh: (it's the first time I've tried changing a cam chain). Now the plates have burrs where the rivetted end of the pin pushed through them (see attached photo). The burrs make the link bind.
As far as I can tell, I can't file or peen the burrs down as the finish would probably be too rough for the chain. Plus the fact that the burrs are there means the holes will have deformed a bit.
The only way to salvage the new chain, as far as I can tell, would be if I could get some new intermediate plates and another joiner link (which consists of the two side plates and two pins). But I don't know if you can get individual plates.
Anyone have any suggestions?
I'm hoping to get out to Mt Eden Motorcycles tomorrow evening, have to see if Ricky can trade/sell me some exhaust shims and will also ask him about the chain and order a new one if I have to.
WINJA
4th December 2005, 13:43
Crap! I think I've stuffed a new cam chain!
Anyone have any suggestions?
USE THE CHAIN IN AN ARMED ROBERRY AND USE THE CASH TO BUY A GOOD BIKE
DingDong
4th December 2005, 13:47
My advice... dont do anything, take it to the shop and wear the cost of your error:eyepoke:
erik
4th December 2005, 13:50
USE THE CHAIN IN AN ARMED ROBERRY AND USE THE CASH TO BUY A GOOD BIKE
:laugh:
I'll keep that in mind. I get my full licence in january and if I haven't saved up enough cash...
erik
4th December 2005, 13:53
My advice... dont do anything, take it to the shop and wear the cost of your error:eyepoke:
But if I did that, I wouldn't learn how to change a cam chain.
Plus, even if I have to buy another chain, I'll still be saving money on paying a mechanic to do it (assuming I get it right next time...).
Sniper
4th December 2005, 14:00
Learning bears its costs. If you don't have a manual, I would suggest not going to do something important.
Take it to a mechanic matey.
DingDong
4th December 2005, 14:04
But if I did that, I wouldn't learn how to change a cam chain.
Plus, even if I have to buy another chain, I'll still be saving money on paying a mechanic to do it (assuming I get it right next time...).
Agreed... but study up first (get a manual or someone to guide you) it can be a very costly lesson if your chain fails at 100kph, and Winja will reply "TOLD YOU SO!"
DEATH_INC.
4th December 2005, 17:35
Don't worry about it, they're usually tight after you re-rivet them,and you can't remove material before pushing 'em out or you don't have anything to rivet over when you put it back together.
erik
4th December 2005, 18:10
Don't worry about it, they're usually tight after you re-rivet them,and you can't remove material before pushing 'em out or you don't have anything to rivet over when you put it back together.
So you reckon just ignore the burrs and rivet it back together?
T.W.R
4th December 2005, 19:51
So you reckon just ignore the burrs and rivet it back together?
file the burrs then use the new joiner supplied, compress the rivets properly with the chain rivet tool.
the inner plates take the lateral pressure of the chain, the outer plates take the torsional pressure. so when the joiner link is fitted & the rivets are compressed the link will be fine.
DEATH_INC.
6th December 2005, 18:59
So you reckon just ignore the burrs and rivet it back together?
Yep,unless it came with the joiner.
erik
6th December 2005, 21:48
Thanks for the advice, Death and T.W.R.
It's nice to know the burrs aren't a major problem
After actually trying it, I found I could carefully flatten the burrs by beating them with the wrong end of a nail punch.
Joining the new chain to the old to thread it through was a bit tricky at first trying to hold the pin in position and press it in place with the chain tool.
I dunno how you guys do it, but I had to make a guide to hold the pin in place (part of a bolt with a hole in it that the pin and chain tool pin could fit in - basically a tube, but I didn't have any tube the right size).
I was sold a joiner link with the chain, so when I removed the second pin from the new chain, I ground the head off. It worked well, the plates didn't get damaged at all.
So right now the new chain is in the bike with the joiner link in place but the pins haven't been riveted yet. I think I'll experiment a bit riveting the old chain before I attack the new one. The rivet tool in that came with the chain has a rounded end (slightly flatter than it originally was after I tried it on a pin in an old final drive chain). It's different to the method I've seen described of punching a cross and a centre punch, so I don't think I trust it. The manufacturer's method of riveting the links seems to be to squish two edges of the pin a bit and I'm trying to make up a rivet tool that will do that for the chain tool. I'll see how it goes on the old chain first.
Interestingly, the old chain showed no signs of burrs after pushing the rivet through. I don't know if there is any difference in the hardness of the steel used in the chains, but I did find that the riveted part of the pin on the new chain was 2.9mm across whereas the riveted part on the old chain was only 2.8mm across (pin diameter is 2.7mm in both cases).
The pin from the old chain had quite noticeable grooves in it from wear. I'll measure the old chain later to see how much it's streched across a number of links (gotta go and find what it should be).
Wasp
6th December 2005, 21:53
just a few quick Qs
what is a cam chain and what does it do?
my mechanic said i need to replace the cam chain(s) and tensioners, how much is this going to cost to buy the chain and tensioner? how long would it take if i got him to do it?
Kwaka-Kid
6th December 2005, 22:26
VT250 = more expensive because long camchain running around the twin.. cost? dunno.
Erik: Yeah just however man, i have joined heaps of camchain with just a hammer and nail/whatever form of punch is within arms length ;) Its amazing how well they just hold together. And fully agree with death dont worry about the burrs, its amazing how not-rocket-surgeory it is, but at the same time, a critical piece in the workings of that revvy beast.
T.W.R
6th December 2005, 22:35
Thanks for the advice, Death and T.W.R.
It's nice to know the burrs aren't a major problem
So right now the new chain is in the bike with the joiner link in place but the pins haven't been riveted yet. I think I'll experiment a bit riveting the old chain before I attack the new one. The rivet tool in that came with the chain has a rounded end (slightly flatter than it originally was after I tried it on a pin in an old final drive chain). It's different to the method I've seen described of punching a cross and a centre punch, so I don't think I trust it. The manufacturer's method of riveting the links seems to be to squish two edges of the pin a bit and I'm trying to make up a rivet tool that will do that for the chain tool. I'll see how it goes on the old chain first.
glad to hear you didn't strike any hassles with the rest of the job. I wouldn't have slipped the joiner into the chain though before i was ready to finish the job, just needs someone to play with it & the joiner could say bye bye down into the sump! lacing the chain ends together with a piece of wire may have been safer.
the punch in the kit relys on compression spreading, and the technique you describe actually fractures the rivet end to achieve the spread. the factories obviously use a fully automated system of machines to do the work, but the rivet spreading is done by a 2 or 4 dogged compression punch.
the tool has a sprung loaded system to hold the chain in place so you shouldn't have to much trouble completing the job.
TLDV8
6th December 2005, 22:52
What is a cam chain and what does it do?
Generally it is an endless chain driven by a gear on the crankshaft which goes to the top of the engine to drive the camshaft or camshafts at half the crankshaft rpms.The tensioner is normally a blade type on the trailing side of the chain with a spring or hydraulic loaded ratchet,when they are worn,things get very noisy at idle speeds.
This is the topend of a Suzuki TL1000 V Twin...a little different since the cam chain drives a idler gear which in turn drives the 2 camshafts,one for inlet,one for exhaust...a more common method is the chain coming up and driving on cam sprockets.
Here is a pic..the curious may notice the 2 cam postion sensor's ; )
http://i30.photobucket.com/albums/c345/manurewa/Scissor3.jpg
http://imageevent.com/tldv8/camsscissorgear
erik
7th December 2005, 22:22
I've been experimenting riveting links on the old chain. My attempts at making a different rivet tool have failed, the steel hasn't been hard enough and has just dented (shaft of an old screwdriver. when I tried to harden it, it fractured, but that might've also been due to the shape of the tool). So I've been using the rounded rivet tool that came with the cam chain tool.
I think I'm getting the feel for it, the last one I did (from right to left) seemed ok and wasn't way too stiff. (second to last one I wanted to see what a little bit tighter did).
Stay tuned for more riveting entertainment when I do the actual link (tomorrow probably, have to sleep now). :p
Pixie
7th December 2005, 23:32
I've been experimenting riveting links on the old chain. My attempts at making a different rivet tool have failed, the steel hasn't been hard enough and has just dented (shaft of an old screwdriver. when I tried to harden it, it fractured, but that might've also been due to the shape of the tool). So I've been using the rounded rivet tool that came with the cam chain tool.
I think I'm getting the feel for it, the last one I did (from right to left) seemed ok and wasn't way too stiff. (second to last one I wanted to see what a little bit tighter did).
Stay tuned for more riveting entertainment when I do the actual link (tomorrow probably, have to sleep now). :p
If you want to make a really hard punch,Use a Ramset nail,the ones that fasten into steel RSJ's.
You can grind it to a point or chisel,but don't over heat it when grinding
erik
8th December 2005, 22:10
If you want to make a really hard punch,Use a Ramset nail,the ones that fasten into steel RSJ's.
You can grind it to a point or chisel,but don't over heat it when grinding
Thanks for the tip, I haven't come across Ramset nails before.
Seeing as the exhaust shims haven't arrived yet, there was no pressing need to rivet the chain straight away, so I decided to have another go at making a different rivet punch.
I had some music wire left over from my model airplane days and initial tests showed it was fairly hard. So I got a piece of 3.2mm dia music wire, made a punch similar to the shape of the rivet head, then got a piece of 6.35mm dia music wire, heated the end till it was a dull red (as hot as I could get it with the hobby butane torch I have) and punched the end of the 6.35mm dia rod with the smaller punch. Quenched it in oil but it started to dent when I tried it on a rivet, so heated it up and punched it a bit more, then heated it as much as I could (still just dull red/orange) and quenched it in water. It seems to be hard enough now, doesn't seem to dent after riveting pins in the old chain. It seems to do an ok job (see photo).
Now I just have to grind the diameter down to 5.5mm in my lathe ;) so that it fits in the cam chain tool.
erik
10th December 2005, 20:37
The shims arrived on friday, I got them from Precision Shims ( www.precisionshims.com.au thanks to crash harry for mentioning them).
After messing around with the punch I made, I still wasn't really happy with it. In the end, it broke when I tried riveting a pin the the old chain using a hammer rather than the cam chain tool.
So in the end, I tried the rivet tool that came with the cam chain tool. But from all the practice I'd done on the old chain, the tool had become rather flat. So rather than indenting the pins, it just squished them.
I ended up grinding the broken rivet tool I made to a rounded end and hardened it and used it in stead. I didn't get it perfectly lined up, but it'll be ok I think.
With the new exhaust shims and cam chain, I swear the exhaust sounds slightly different. More kind of "poppy" or like a musical note, rather than before.
It's still not running right though ;)
But it's good that I've done the chain and shims now. :yes:
Gixxer 4 ever
15th December 2005, 21:55
Your crimp looks good. I noted when we put the new chain in tonight on the, GPX 250, the pins are tight and it only takes a small amount of crimp to secure them. We worry about these things to much.:shifty: You did good. :woohoo: But if the chain in the picture is the one you fitted why didn't you use an endless chain? Because if that is the chain you are fitting it is now endless but not installed. :confused:
You say it is not running well. What is the problem?
erik
16th December 2005, 00:04
Your crimp looks good. I noted when we put the new chain in tonight on the, GPX 250, the pins are tight and it only takes a small amount of crimp to secure them. We worry about these things to much.:shifty: You did good. :woohoo:
Cheers.
But if the chain in the picture is the one you fitted why didn't you use an endless chain? Because if that is the chain you are fitting it is now endless but not installed. :confused:
You say it is not running well. What is the problem?
The last picture of the crimped chain is of the end of the chain hanging out of the top of the engine. It is installed, just the cloth (to keep dust etc out of engine, yeah I probably worry too much ;) ) is hiding the engine.
Gixxer 4 ever
16th December 2005, 05:59
Cheers.
The last picture of the crimped chain is of the end of the chain hanging out of the top of the engine. It is installed, just the cloth (to keep dust etc out of engine, yeah I probably worry too much ;) ) is hiding the engine.
Cool. we do as well.:mellow: Still nice to get these jobs :done:
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