I just looked at the price list. Twenty Five cents per Inch O cam chain! Wooo Hoo, talk about a deal..Looking at more in freight than the service.

Putting a new chain on a "one chain worn" set O gears was no problem. I also had the worn guides in the equation. The tensioner was out something like 8 mm of the 18 allowable with the rear guide bent as much as I could bend it.
So, question is, In my mind, how tight would the tensioner have been with new guides? I expect new guides would have yielded a tighter chain, but the 8 mm wouldnt have gone away. When we are talking about side deflection of 8 mm, the length change is very small, considering the length of the chain. I would say ~2.8 mm of chain length is soaked up, OHH, but it's done twice, above & below the tensioner, so 5.6 mm of chain length would be taken up by an 8 mm deflection.( I didnt draw any models, just used the square root of 8 as the difference between the imaginary straight line of the chain with no tensioner on it & the triangle created when the chain is deflected, so you engineer types may see a glaring oversight. PLease, feel free to correct my thinking if I am off base.)
Remembering that the cam drive gear is removed to get the chain on & that the amount O slack was minimal I wouldn't think the chain could be much shorter & still get it on.

UNless, the ID of the cam drive gear could be relieved to allow it to sit lower on the cam while the chain was slipped over the teeth. Hmmm, that sounds doable. Just have to do it on both sides for balance & stay away from the bolt holes & index pin.LOcate the hash marks that line up with the head & go up & down with a grinder ,,,, OOOPS, wouldnt that load the bolts with the whole cam chain varying tension? Doesnt the cam drive gear fit snug on a shoulder? I'm not sure the ID of the gear isn't somewhat load bearing. If so, relieving it to get a tight chain on might be a bad idea.

I brought up the same thing quite some time ago & someone else, who can do the math, showed the stresses that put on the chain. I dint remember how it went, but I think the ratchet is gonna need to stay, else the chain would flop violently about forcing the tensioner spring back, only to extend again s soon as the rpm drop. Would that really be a bad idea? I dunno, BUt, my answer was to add a spring to the mix, outside the tensioner, so when the pawl catches with the chain tight, there would be a "give" left in it to soak up the stretch. It could be put into the tensioner extension that has been added by some to make the tensioner not reach the 18 mm limit so quickly & would have to be stiffer than the tensioner spring inside the tube.

Removing the rachet is an idea worth looking into.  One of Norbert's design's does replace the stock adjuster with a damper device.

My thought's on the adjuster was that maybe the rachet systmem helps keep the chain from getting too slack and whipping about.  Assuming everything is 200°F, there's a .014" difference in the thermal growth between the cylinder and chain.  There will be more if the cylinder is hot and the chain cool.  I've measured the temp's after a hot run and the cyl head is over 240 and the base is 180.  So the chain will be .028" shorter on a hot run.  Maybe enough to click over.

There is a place on the back side of the cylinder, just above the mounting bosses, where a hole could be placed to allow a plunger to push on the tensioner guide.  My idea at the time was to give the guide a little support in the middle as it was discovered that this guide is completely flat and a little bow in the guide helps take up the slack.  My chain was .01 long and the plunger was out 22mm.  I'm guessing it started about 10mm out to begin with.  Replacing the rear guide only took up about 2mm.  So roughly, 10mm plunger travel for .01" chain stretch.

One of our biggest issues (at least mine) is not being able to observe whats going on inside.  And popping off the cover every week is a lot of work.  

So here's an idea, an external adjuster, manual or automatic.  Drill a hole thru the case either at the afore mentioned location or a new spot in the engine case to place an adjustment screw.  A cantilevered leaf spring and a pointer would be an easy way to determine tension.

Any comments?  

Oldfeller2 wrote on 12/31/69 at 16:00:07:

Maybe that's why this problem has gotten so much worse in recent years. Suzuki might be having the same problem.

Ken

Update:

Tsubaki got taken to task a bit -- they advertise bragging rights to a quarter inch pitch (6.35mm) silent chain on their home web page.  Tsubaki America finally admitted the quarter inch pitch chain is only manufactured under license for "certain Pacific Rim OEM suppliers" and cannot contractually be sold back to America at all.

Rest of the story comes from Morse.  I got back their report on the chain and gear that I got from Lancer.  It is a Morse Type 82 silent chain that was manufactured by their Japanese subsidiary (guess who) and it is their best and only quarter inch chain of the Type 82 (motorcycle style) silent chain family.  They do not offer their hard pin in that style -- the chain is too small.  They do not offer a HY-VO tension split pin design that small -- smallest HY-VO size is the 3/8" pitch size.  

There is no better Type 82 chain pins or styles available.  We got all that there is in a Type 82 chain.

Comments on the sample chain and sprocket is that it was NOT worn out -- it was approximately a bit past halfway to the engineering wear limit.   This lines up with the service wear limit in the Suzuki Shop manual.


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HOWEVER,

There are automotive style silent chains in quarter inch pitch that will run on our gear forms.  The chains are made of links that are 1.25mm taller (same length -- but they swing a larger pin that sticks out a little longer on the side of things).

As such these chains would require changes to the left side straight chain guide to back the guide away from the chain 1mm and some changes to the top of the tension guide side at the top end edge to keep it from being abraded out of existence by the taller chain as it comes off the cam gear.  

I don't know what the longer protruding pin heads would hit or do to the engine as it ran its pathway.

Would this thicker chain last any longer?  Who knows?  
It was built for a dual overhead cam car engine and would require modifications to our engines to fit at all.

That's it, the last silent chain vendor has reported.  

Any opinions on the taller automotive chain and what it would hit if someone tried to install one in a Savage?

Oldfeller

Hey guys...
Just wondering if engine mods (more HP) puts added stress on an already suspect part of the engine? It would be interesting to see how mileage/mods/replacement compares to stock engines.

Oldfeller2 wrote on 12/31/69 at 16:00:08:

Well, thanks for trying so hard to find a chain. I'm sure it was frustrating to keep hitting dead ends. I think I'll order verslagen's modded adjuster and slap this puppy back together.

Don't know if I'll keep her yet. I may have to ride her for a week before I make any permanent decisions.

Thanks again.

Ken