It's true, I do worry too much about machines, but perfection is difficult if not impossible to accomplish unless you are God. Also, most good machines are the product of a worrying engineer, while most bad machines are the product of an overly confident or untrained engineer.

I believe that’s what I said in an earlier post so I'm not really sure about what you are disagreeing about. The chain stretching isn't really the main problem; it’s the brittle guides that fracture with an otherwise not problematic amount of chain stretch (as in not affecting timing etc). Some people have even replaced their chain at 100k (but not the guides) and suffer the same fate. That is why it is always recommended that the chain and guides are replaced together. The chain slaps against the plastic guides that get brittle with age and with some engine dynamics, a part breaks off and gets between the chain and the sprocket and then the top end of the engine is gone. This replacement (chain, guides, and tensioner rail) is recommended for any late 80s or early 90s MB v-8 every 100K mi or more. The design flaw is the brittle guides, though a slacking chain accentuates this problem. I had thought I said this earlier.

I agree that the stresses are minimal for the link trying to fall outward from the chain, but this is true only for static loading. In dynamic loading all hell can break loose and harmonics of the engine's explosions and chains rotation and slapping can certainly cause vibrations that are in the direction axial to the chain's link. Perhaps the e-clips can still hold the link on, but it just makes me feel squeamish.

Ask any engineer, if a structure is exposed to both static and dynamic loading, it’s the dynamic vibrations are the chief concern to structural stability for the long run and the primary factor that decides the structural dimensions to support these loadings. Vibrations are a huge portion of engineering and not one of the easier parts either.

I once taught a dynamics course for turbines and other high speed rotating machines once. You’d be absolutely amazed how much force can be produced from a tiny unbalance (which is inevitable) in any spinning object. The other interesting thing was in what direction are these forces produced, not at all in the directions you’d think. For even marginally realistic problems, huge FEA codes are needed to estimate these loads while even at best the output is still conservative. This is why high speed turbines such as turbochargers require such precise machining. Though, I’ll admit that the chain is spinning at a much slower speed, it is however running in a non-concentric pattern and has a mass far grater than most turbines for small engines.

Again, I don't disagree that MB took this loading into account because these cars were build by some of the best engineers in the industry, but these clips are spinning and sliding around at a couple hundreds rpm; this still makes me worry. I’d still rather have a crimped clip but I guess if there is no other choice, I’ll have to go with it. Hell, they were wrong with the chain guides, so they could be wrong with this too.

ATLD