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Message started by DragBikeMike on 07/01/20 at 23:39:32

Title: Cam Chain
Post by DragBikeMike on 07/01/20 at 23:39:32

I have a pile of old cam chains that came with packages of old junk I bought on eBay. Sort of a collection.

I also have a brand new OEM cam chain that I plan to install on my big bore project.

It was inevitable that sooner or later the new chain would end up sitting next to an old chain. Any of you ever see a 2016 or newer OEM chain? It's different.

Title: Re: Cam Chain
Post by DragBikeMike on 07/01/20 at 23:52:24

The 2016 and newer chain has pins about 1/2 the size of the older chains. There are a lot of other differences too. The link plates are about the same thickness, but the side plates are a lot thinner. The side plates also have a much different pattern/footprint.

I wasn't sure if they sold me the correct chain so I started reviewing all the parts fiche starting way back. The change came in 2016. Up until 2016, the part number for the chain was 12760-24B00. In 2016 it changed to 12760-24B10.

The price changed dramatically too. The old chains are $134. The new chains are $88.

I have just under 10K miles an my bike. It has the same chain that was delivered from the factory. I reviewed my old photos and sure enough, I have the chain with the funny side plates and smaller pins.

Now here's an interesting tidbit. That chain tensioner has not drifted out much at all. I'm in there all the time fiddling around with stuff and it never seems to change. That's even after running it for about 3000 miles with my special jack bolt and the super-short cylinder.

I beat that sucker up. I have a love affair with 7000 rpm. This chain with the teeny-weeny pins seems to hack it.

Title: Re: Cam Chain
Post by DragBikeMike on 07/01/20 at 23:54:08

Here's a different shot of the two chains. The 2016 chain is on the left.

Title: Re: Cam Chain
Post by DragBikeMike on 07/02/20 at 00:11:49

I weighed the two chains. The 2016 chain weighs 255 grams. The older chain weighs 289 grams.

Armen, how did you miss that? ;D

I wonder why the factory switched to the lighter chain? I guess the logical conclusion is that it's cheaper. I'm not so sure. The lighter chain seems to be holding up a lot better than the norm. Granted, it lived for about 3000 miles with a tensioner assembly that had no pawl, but that tensioner was set up with a hard stop that limited travel to around 1mm. All the other miles were logged with a stock tensioner. And a whole bunch of those miles are with heavy duty valve springs and a high lift cam. I just don't see much, if any, change in the tensioner extension.

Do you think they're tryin to reduce the stress on the tensioner/guide? That heavier chain certainly imparts a lot of force when it turns the corner at the sprockets. The centrifugal force must be off the hook at high rpm, and the guide has to hold the chain back. Since the drive side is under extreme tension, I'm gonna make the bold assumption that the stress imparted by the chain is confined to the rear guide.

I'll probably be in that clutch cover pretty soon. I'll make sure to check it and report the results.

BTW, all the other parts have remained unchanged since the beginning of time. The guides and sprockets have the same part numbers they started out with back in the eightys.

Title: Re: Cam Chain
Post by LANCER on 07/02/20 at 03:54:50

What was the difference in the measured chain stretch between the two ?

Title: Re: Cam Chain
Post by DragBikeMike on 07/03/20 at 00:45:07

I didn't measure chain stretch. The 2016 is brand new, never used, so I suspect it won't have any wear. But I think I will do some measurements just out of curiosity.

I have six early style chains. No idea about the history on those six chains. I think it might be interesting to measure them all and compare. I will post results.

So Lancer, have you ever seen one of these newer style chains?

Title: Re: Cam Chain
Post by LANCER on 07/03/20 at 09:03:59

Nope, I have not.

But I will be looking for these things from now on.

Title: Re: Cam Chain
Post by Jdvt600 on 07/03/20 at 09:21:08

How do the two oem versions compare with the nitrided cam chain available from Lancer?

Self deprecating disclaimer: I'm not an engineer and have a less than basic level of knowledge about internal combustion engines. I do however appreciate the information shared here and the ability to inform my purchases. I suspect the general consensus is that the differences are minor and I should just check the wear on whatever chain I install.

Title: Re: Cam Chain
Post by SavageMan99 on 07/03/20 at 09:28:29

Just my personal choice...
I run both the modified tensioner and the nitrided chain. Losing your engine due to a cam chain failure would suck.
If I didn't already have the starter kickback safety I'd add that too.

Title: Re: Cam Chain
Post by justin_o_guy2 on 07/03/20 at 10:43:21

Tensioner mods come in different flavors.

Making it so it cant spit its guts out and kill the engine, making it longer, to use the chain longer,, both very good improvements,, Available at your LOcal Versy Store,,

Then along comes a radical who decides
That ratchet pawl is the main culprit,,and he does away with it,
The voices decryiing such foolishness were everywhere,
but he did it anyway
Hes still riding it, I think the same chain is on it, everything works fine,,
My memory isnt so perfect as Id like, but I think a coupld others have followed,

So,, about that Nitrided chain,,

After seeing really big differences in OEM cam chain life, we all started looking at
Average ride length,, as a beginning clue.
Every time the engine warms up to full operating temps, the cylinder grows Taller,, and the tensioner is always working to click that pawl into a tooth and keep that chain nice and tight,,

Well,, how much differently will a nitrided chain wear when its being tortured by mechanical forces that nothing is gonna stop?

I doubt the nitrided chain lasts noticeably longer in that environment,,
But, Slap that dude into a spot where the tensioner doesnt have a pawl,, and would it need to be nitrided to last 50,000 miles? WE havent seen that test, but IM goin with
Problee Not,,

The chains in the side by side picture , tho,, I think seeing which lasts longer is a no brainer,.

What we Call Chain Stretch is really the accumulation of wear at the pins.
The thinner plates means a decreased "Bushed" area where the pin passes thru the plate, and the smaller diameter pin does the same thing,,

And that crappy , wimpy chain might just run and run and run in Batmans setup..

Not sure what all the did inside there,, not sure where to go look,, but when I start gettin my bike back o the road, IM doin the Batman conversion on my existing Verslavy..

Or,, MAYBE, Ill do the little modification I came up with that accomplished kinda the same thing without removing the pawl,,
I have the spring all picked out and taped on the side of the toolbox,,

Title: Re: Cam Chain
Post by badwolf on 07/03/20 at 11:29:56

I did not want to start a new thread for this, but you guys have brought it up,,so.
I put in my nitrated chain at 80,000 miles. I did not change the cam chain follower. When put together my home extended plunger was at 0 mm extension.
I checked it at 100,000 and it was out 3 mm.
I took out the pawl spring, and turned the plunger upside down so the teeth were on top and the pawl did nothihg. I also cut 2 coils off the plunger spring.
I just checked it at 106,000 miles while beefing up the clutch and it is out 3.5 mm.
Sooooo, I think the expansion/contraction is the main cause for wear, not to the chain, but the follower. I think my follower was wore more than my chain.
Would love to see someone changing their chain to try swaping a new follower on the old chain first to see where the wear is the worst, chain or follower.
I don't plan on checking my plunger again till I hit 150,000 miles, and I lenghted my plunger myself so there is no saftey pin.

I am NOT telling everyone to do this, just relaying my thoughts. If the engine kicked backwards I am sure a valve might get bent, that is why the plunger (pawl) is there in the first place. But I have yet to have my bike do that. Knock on wood. (my head)

Title: Re: Cam Chain
Post by justin_o_guy2 on 07/03/20 at 15:36:33

If the engine kicked backwards I am sure a valve might get bent, that is why the plunger is there in the first place.

Thats where the pawl would come into play,, makes sense,, Id never thot about the Kickback moment,,
Gurus? What say ye all?

Title: Re: Cam Chain
Post by norm92de on 07/03/20 at 16:11:55

I don't know what I have done but I left out the pawl spring and limited the backward travel by putting a stopper pin in the assembly when I last opened her up. Not very many miles on it since.

Oh my god! I will burn in hell but I will bet my Suzuki won't. :)

Title: Re: Cam Chain
Post by justin_o_guy2 on 07/03/20 at 17:01:15

I wish Batman would show up and give us another quick rundown on his mod,,
Id shine the light in the sky, but IM afraid everyone of Chinese ancestry would see it and conclude supper is ready,,
I couldnt feed them,, and I dont have any bat soup,, zero,,

Title: Re: Cam Chain
Post by DragBikeMike on 07/04/20 at 01:58:44

"Sooooo, I think the expansion/contraction is the main cause for wear, not to the chain, but the follower."

Badwolf I agree. I don't think the chain wears much. I think the follower is the culprit. I suspected that when I saw an old post from a member named "Ares" (hope I spelled that correctly), and I kept seein posts where members installed new chains and the tensioner was still extended too far. I don't think it's wear as much as the follower loosing it's arc.

When I built my tight quench motor, I machined about .130" (3mm) off the top of the cylinder (that was one loose cam chain). Then I installed a jack bolt to bear on the top portion of the rear chain guide/follower. The jack bolt drives on the follower and increases the arc. I could put that tensioner anywhere I wanted it with that jack bolt. All my cylinder heads have the jack bolt installed and ready to go if I need it.

I have a good setup for measuring the chains now. I took some preliminary measurements today. They are interesting. I will post the data when I'm comfortable that the readings are repeatable and accurate.

Title: Re: Cam Chain
Post by Dave on 07/04/20 at 03:42:22

I removed the pawl, left the extension spring inside, and made a spacer that limits the backward travel. I left about 1mm of space for the plunger to move backwards as the engine warms up. I did that 2 years ago but I did not ride the bike much last summer as I was fighting a handling issue and I had 2 other bikes to ride.

Not sure how long it will be before I open the engine up to peak inside. I think my next experiment will be to fiddle around with the clutch plates and see if I can figure out a way to make more grip.

Title: Re: Cam Chain
Post by badwolf on 07/04/20 at 06:26:15

Dave, I just added one steel plate to the clutch pack and made a longer pushrod to get the adjustment right, and it made a world of difference!
I was getting a little slipping when hitting it to pass or shifting hard. Now it is much more solid. One clutch plate, a short piece of rod and finally broke down and installed a new gasket. A cheap fix, and it worked.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:37:21

So, a total of seven chains. Six are used junk that I got from various eBay bulk parts purchases, and one is a brand new 2016 OEM chain. Time to do some measuring. I used this setup to guarantee an even playing field for all the chains. The ten-pound weight ensures that each chain has exactly the same amount of force applied.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:38:37

The factory service manual specifies a wear limit of 5.070” over 21 pins (center-to-center). It’s pretty hard to measure that right to the gnats behind so I rounded to the nearest .005” increment. Here are the results of pin measurements.
New 2016 chain: 4.990”
Chain #1: 5.005”
Chain #2: 5.010”
Chain #3: 5.010”
Chain #4: 5.010”
Chain #5: 5.000”
Chain #6: 5.005”
As you can see, none of these even come close to the wear limit. Either I’m awfully lucky and randomly got a whole bunch of perfectly good $130 cam chains from engines that all had almost zero mileage….or…..the chains don’t wear out very fast.

3/17/22 Measured original OEM chain after logging about 23,500 hard miles. It (chain #7) was 5.010”.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:39:22

Let’s try another method of measurement. I measured sprocket bore to sprocket bore. That will also account for any wear on the chain cleats.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:41:22

Results for sprocket to sprocket are as follows.

New 2016 chain: 10.290”
Chain #1: 10.310”
Chain #2: 10.330”
Chain #3: 10.320”
Chain #4: 10.340”
Chain #5: 10.310”
Chain #6: 10.335”

If you consider that the factory wear limit on the pin measurement is about .080” over a brand new chain, and then look at how much the sprocket to sprocket measurement varies new vs old, things still look rosy for the used chains. Worst case (chain #4) is only .050” greater than a brand new chain.

3/17/22. Measured original OEM chain after logging 23,500 hard miles. Chain #7 was 10.343”.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:42:01

Let’s look at the rear chain follower, the one that keeps tension on the chain. This is an old used follower (eBay bulk junk purchase) compared to a brand-new OEM follower. Note how much greater the arc of the new follower is compared to the flattened out used follower.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:42:38

Here’s another shot. You can see the rear guide’s get up & go got up & went. I contend the problem most lies in the rear chain follower/guide.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:43:14

In this picture, you can see the guide is old and cracked, but the rubber is not worn away. The guide is not robust and looses it’s arc.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:43:49

The jack bolt installed in the head rectifies the problem by restoring the arc of the follower. It allows the tensioner to maintain correct extension (12mm or less)), and in doing so, keeps the drive side of the chain well away from the slack side.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 01:44:44

Extending the tensioner with the Verslavy is a good fix if you don’t have the cylinder head removed, but if the cylinder head is off, I think adding the jack bolt is a really good option. It’s not very difficult and keeps the cam chain geometry closer to the original design. It also allows you to adjust the system during regular inspection and maintenance.

Title: Re: Cam Chain
Post by badwolf on 07/10/20 at 10:01:49

Mike, GREAT WORK!!! When I changed my chain at 80k I could not see any wear on the old one in slop or twist. Looked at the follower but saw no real wear on the surface so put it back in. I did not have a new one to compare it to. Now you have comfirmed my thoughts the follower is the culprit. The heat/expand - cool/shrink cycles combined with the pawl on the plunger is too much stress for it to take. Next time I have mine apart, I'll see if beefing-up the curve is possible.
When you are reassembling the engine try the old and new followers and compare the plunger extenson.
Your jack bolt looks good, but if the follower could be restored to stay at its stock curve I could leave the head on. I'll do a compression test and check oil usage at 150k, if things seem good I'll try to get to 200 before a rebuild.
I don't push hard any more (old) and my high gearing keeps me under 4 grand almost all the time. I'll shoot for 200k without spliting the cases, or pulling the jug or head.
I think the best thing to do is - AFTER BREAK - IN - remove the pawl and put a spacer behind the plunger with 1 - 2mm movement allowed. Without the heat/cool cycles stressing the follower it should retain it's shape and allow the chain to run it's life (100k+ miles ) without the plunger blowing up the primary case.

Title: Re: Cam Chain
Post by verslagen1 on 07/10/20 at 10:29:35

I proposed doing that at the bottom of the cylinder and was poo-poo'd.
But it looks like you found a spot with more meat.
and there is a spot behind the starter that we might be able to put in a manual adjuster

https://thumpertalk.com/shop/ThumperTalk-Manual-Cam-Chain-Tensioner-ENG-TT-MCCT1-p2006766344.html

Title: Re: Cam Chain
Post by norm92de on 07/10/20 at 10:53:07

When I removed mine I was surprised at the flexibility of the system, (read rear guide.)

As stated before I removed the pawl spring and restricted the rearward movement of the plunger.

We can only speculate about- what if Suzuki had done what every other manufacturer does, i.e. a spring loaded adjustable plunger at the rear of the cylinder.

How easy is it to remove the rear guide with the cylinder in place?

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 11:18:26

"I proposed doing that at the bottom of the cylinder and was poo-poo'd.
But it looks like you found a spot with more meat.
and there is a spot behind the starter that we might be able to put in a manual adjuster"

Versy, I was initially looking at that area, but the oil feed hole runs right there. It just didn't look like I could install the jack bolt without breaking through the feed hole. So I moved on to plan B and looked at the head. As it turns out, the location in the head more closely aligns with the original location of the arc's apex. It's a perfect spot and functions perfectly.

Hey, how do you get to that ThumperTalk report? The link doesn't work for me.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 11:26:13

Norm, it's fairly easy to remove the rear guide with the cylinder in place. I checked that when I first set up my tight quench engine. Did some mockups with the engine out of the bike to make sure I would be able to do it. I wanted to be able to periodically inspect the guide.

You have to remove the clutch to provide enough room to pull the guide down & out. You also have to pull pretty darned hard. When it goes back in you also have to push up pretty darned hard. Putting a small chamfer in the material around the pivot bolt helps. Then you have to get that bolt through the hole in the head & guide, but I did it without wrecking anything. Just takes patience. Tenacity helps too.

Title: Re: Cam Chain
Post by DragBikeMike on 07/10/20 at 11:38:52

Taking the pawl out will relieve some stress on the guide, but you lose control of the intake closing event. Limiting the back-travel with a stop in the tensioner mitigates the valve control issue, but not under all conditions. If you remove the pawl and don't install a stop to minimize the back travel, you end up with the plunger moving back & forth a whole bunch. If you are looking for performance, valve control is pretty important.

This photo gives you an idea of how much that plunger moves around when the pawl is completely removed. I removed the pawl and greased up the plunger, then rotated the engine through several times. Each time the intake cam lobe goes over the nose the valve springs drive all the slack out of the rear side of the chain. It causes the plunger to retract. The result is the intake valve closing way before it should. It also negates the deceleration ramp ground into the cam lobe because the valve is driving the cam rather than the cam holding back the valve.

Title: Re: Cam Chain
Post by norm92de on 07/10/20 at 13:25:25

DBM,
Thanks for the reply. Very helpful.

Title: Re: Cam Chain
Post by verslagen1 on 07/10/20 at 14:06:30

should work now

https://thumpertalk.com/shop/ThumperTalk-Manual-Cam-Chain-Tensioner-ENG-TT-MCCT1-p2006766344.html

Title: Re: Cam Chain
Post by Armen on 07/10/20 at 20:55:27

Hey Badwolf,
Did you add a friction plate or steel one?
thanks

Title: Re: Cam Chain
Post by badwolf on 07/10/20 at 21:23:04

I doubled up one of the steel plates. It was .060'' thick. Then had to make a new pushrod that much longer.
I can't get to slip now at all. The pull seems just a little bit harder, but not much.

Title: Re: Cam Chain
Post by Armen on 07/10/20 at 21:29:14

Thanks!

Title: Re: Cam Chain
Post by Dave on 07/11/20 at 03:37:29

If you are going to try adding a steel plate - add it where the friction plate rubs against the aluminum hub. MMRanch said his inner hub had worn and when he added a steel plate the slipping stopped.

Title: Re: Cam Chain
Post by Armen on 07/11/20 at 06:23:27

Thanks!

Title: Re: Cam Chain
Post by DragBikeMike on 03/17/22 at 23:19:10

Since I have my engine torn apart to repair the transmission, I thought it would be wise to measure the cam chain. The original 2016 cam chain has about 23,500 very hard miles on it. Lots of those miles with heavy valve springs and high lift cams.

The 21 pin measurement is 5.010”. The sprocket to sprocket measurement is 10.343”. If you look at the data I posted two years ago you can see this well used specimen is right about where all the other chains were in the original post.

The majority of the miles were logged with a tensioner that utilized a pawl. The chain just doesn’t seem to wear very much at all.

If any of you have chains with known mileage and operating conditions, howzabout measuring the chain using a technique similar to the one I used in this post. Record your data here so we can see what the trend is.

Title: Re: Cam Chain
Post by TheSneeze on 03/18/22 at 08:52:58

My bike's odometer reads 9800+ miles, but it's use is a complete unknown (other than the uphill cam lobe starving for oil). I will measure my chain and post up what I find, but I won't be able to use the sprocket to sprocket method as I don't have two sprockets. Oh wait - I might have another in the pile of engine parts I scored... I will look around, but either way I will post the measurement and method used.

Title: Re: Cam Chain
Post by TheSneeze on 03/25/22 at 13:58:08

To my trained eye, the 21 pin measurement on mine is 127.53mm, or 5.020".

Title: Re: Cam Chain
Post by justin_o_guy2 on 03/25/22 at 16:01:33

Don't just toss a chain on. Put it in something and cover it in oil.

Title: Re: Cam Chain
Post by TheSneeze on 03/25/22 at 17:01:29

Good advise, but not my first engine build. Thanks, JoG

Title: Re: Cam Chain
Post by justin_o_guy2 on 03/25/22 at 23:17:47

Jus tryna help,mang..

Title: Re: Cam Chain
Post by DragBikeMike on 04/02/22 at 11:29:11

Thanks for the data Sneezy. Do you think it's safe to assume your chain had roughly 10K on it? Can you look at the pics I posted earlier to see if your chain is the old style or the new lighter style. It's less than half-way to the wear limit. If it's the original chain, it's only about 35 years old. Takes a lickin and keeps on tickin.

Title: Re: Cam Chain
Post by ThumperPaul on 12/24/23 at 10:27:01

595F502C2E292D1D0 wrote:

Mike, thanks for directing me to this very informative post. It puts my concern about chain stretch to rest. The rear chain guide/follower is the weakest link in the system and would need replacement long before the cam chain itself. Reading your quote, I'm not exactly looking forward to removing and re-installing it. :-[

It's interesting that the Verslavy CCT is more to do with compensating for the aging weak tensioner than actual cam chain stretching itself. And, of course, Suzuki is proud of their rear chain guide follower at $100.