justin_o_guy wrote on 12/31/69 at 16:00:06:


Even the brand new chain I have here does that to a slight degree.

Ken

Justin, I still don't get your point.  The cam chain must be 'indexed' to the driven gear and also the driving gear.  Otherwise the driven gear is not 'indexed' to the driving gear.  And piston meets valves and kerpow!

I think I follow what you both are saying.  The chain is tied positively to the crank by the small driven gear.  Although the chain progresses over the gears in a 2 to 1 ratio, every time the spark plug fires on a gas/air mixture load (every fourth go round) the same set of links get jerked about by the speed up due to the heavy power stroke acting on the small crank gear.

Every time Thumper goes "thump" real hard during one of my right wrist episodes the exact same links are catching hell at the point of thump.  Time after time after time.   Day after day.  It isn't a nice little split up multi-cylinder thing, it is a great big THUMP from a big piston.

Anyhow, I attempted to contact D.I.D., Tsubaki, Morse Hy-Vo,  Ramsey in Charlotte and two far eastern new smaller guys.  So far Ramsey is the only one who has replied (within a day I might add) and they simply don't make the chain we need.  

Shucks, they were the one supplier I thought we could count on being local and all.

Good news, Borg Warner (Morse) just called and wants a picture of the cam chain.  I'll off one of the site's pics and crop out a decent shot of a section of the chain.  BW is sure they already make the chain, its just they make so many variants of silent chain (their proprietary Hy Vo being one example) that they want to make sure they sell us the right one.

Also, I contacted Suzuki and asked them to review the early stretch wear that is going on with the Boulevard 40 crew years 2005-2007.  Having bikes go to full extension on the cam tensioner in 8,000 miles is NOT normal.

Oldfeller

Took some pics of the chain this morning.

http://www.thelongtrek.com/savagecamchain/savagecamchain.htm

The file sizes are big. Please be patient while the page loads.

Ken

The chain should last a minimum of 10k miles.  I looked at mine at 20k and estimate I'll get around 50K from the chain itself.

Personally I'd look at the adjuster every time you retorqued the head bolts.  That's supposed to be every 4k miles.

The time to act is when the adjuster piston sticks out 18mm (housing to shoulder) as it's near the end of travel.  Damage will occur to the adjuster if left in this condition.  And if left to further extend, may disengage altogether.  Causing damage to the valves and piston if the chain jumps out of time.

This is all very good information, thanks to all.

Well, Borg Warner Morse only makes one super premium hard pinned automotive silent chain now and it isn't quarter inch.  They also have a policy against selling bulk chain -- they only provide endless chainsets through a distribution network that guarantees you pay a profit margin to at least 3 people.

There are only two American cam chain companies left -- they are losing their market share to the far east at an increasing rate.  They can't compete on price and their innovations are getting rip/copied just about as soon as they make them.  Our patents are meaningless in China and the Japanese have similar innovations themselves.

(sigh)   I really liked that Borg Warner Morse hard pin chain too.

Let's see who responds next.

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Having taken a strong dip into the silent chain world, I have a new thought.  Most modern silent chain sets have a curved tension pathway as well as a curved return pathway.  Ours has a straight pathway on the right hand side (tension side).  This used to be a common practice, but is relatively rare in the current designs now-a-days.

We have an issue that we never can really "wear our chains out" all the way to the stretch spec limit because the chain will hit itself before it wears/stretches that much.

If we could induce some curve on the right hand side (maybe biased towards the top cam gear side of things) we could use up some of the total deflection space that is currently unused.  We do use all of the deflection space on the left side (biased towards the bottom side of things of course).

Think of a long curve sanded (top bulged) sliver of wood inserted behind the right hand guide, one that is done once during an early inspection to put a bow into that guide, a permanent bow that can't go anywhere and is totally supported by the trapped steel tension of the guide itself acting against the sliver of wood supported by the cast wall.

Now this new permanent right hand side bowing partially counteracts the 7degree retardation that we currently add during the wear out of the chain (think of what the cam does when you insert the wooden sliver, it rotates backwards as the chain is pulled back around it to make up the bow).  

It also provides us some "extra life" out of the existing chain as we have to back up the tensioner to provide the slack to be taken up with the new right hand bow.

Provides extra life.   Recovers part of the 7 degree retardation.  Is within the "wear spec" of the chain.  Cost is some bandsaw and sander time and a small sliver of hardwood.

What's not to like with this idea?  You could do it on an early inspection even if there wasn't enough room yet to install a Slavvy mod or a tensioner adder block.

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I got some good questions asked to me about lubrication.  Does our engine provide a positive means of spraying or dribbling a constant supply of oil on to the silent chain as it runs its pathway?   Silent chain is VERY oil dependent or increased internal wear takes place on the pins.  Motor oil is NOT the best oil to lube a silent chain -- extreme pressure additive package heavy gear oil is the optimum lube for silent chains (but they never get it as a cam chain, they just get thin motor oil -- so they need a constantly replenished stream of that thinner oil to maximize their lifespan).

Oldfeller