TB system isn't like the rest of your car.. There's no reason to expect a 200hp ALH to eat through it's TB components any faster then a stock car. If this were true, we'd be seeing a lot more disasters on this site... I think most people here are running above stock power levels.It does stand to reason the OEM parts will fail when subjected to more torque than they were designed for...
sorta as a rule of thumb... when you approach the limit of the OEM clutch then you have also approached the limit of other components on both ends of the engine.
this ^^x2TB system isn't like the rest of your car.. There's no reason to expect a 200hp ALH to eat through it's TB components any faster then a stock car. If this were true, we'd be seeing a lot more disasters on this site... I think most people here are running above stock power levels.
possible .... someone needs to do some testing
I'll see if I still have my old tensioner laying around in the garage, but back in the day when I was hypermiling, I did thousands of bump starts. I didn't specifically inspect the tensioner, but I don't remember seeing anything like this on it (I think I would have noticed ) and it didn't fail.Popping the clutch for a rolling start? I did have one customer that broke a tensioner catastrophically while doing this, resulting in a head replacement.
Honestly, I'm not sure what causes this. If someone were so inclined they could work out through the gearing to figured out how much tension is being applied to the belt when parked on an incline and the engine is being rotated backwards (rolling backwards when in 1st or rolling forwards when in reverse). I can do a quick test with my car by parking in the driveway w/o my ebrake on, notice the position of the tensioner and then have someone push the car a little to see how much more tension is being applied.do you think even rolling backward can cause this... unless the cam or pump were somehow stuck when it happened causing major deflection in the tensioner... if you notice it's bent away from the max tension stop indicating it hit the max stop ... how did you line up the marks before you took it apart ?
Nope. Just him doing routine maintenance since I last changed the belt.Nick, has anyone else had their hands on the car?... does it still have the ASV?
I would think in the case you are suggesting that the other tang (the one that interfaces with the backplate) would be the one providing the reaction force to you torquing on the tensioner.
The only way I see the tab bending this way is if the spring looses tension.
If you took a new tensioner, and measured the tension at full travel (using a torque wrench?) then compared it with one of the damaged tensioners I bet you'd see a significant difference. As a test to prove/disprove Litens' stated cause of failure...
you could take a new tensioner test it dry, then soak it in oil and test it again.
I don't think an oiled clock springs' tension is going to change much if at all.