i've seen it break pistons, so i'd say the chances are good that there could be damage of some kind.
yes, it is a interference engine
When the belt tensioner fails, you have to stop almost immediately or the engine will overheat and suffer serious damage or destruction. I am assuming that the bolt itself is not stripped; the receiving mounting hole in the engine is stripped. And I am pretty sure that the mounting area is aluminum. Therefore, it should be fairly easy to tap the hole for an over-sized bolt. Select a tap that is just larger than the stripped bolt. I would not recommend the JB weld since if it fails, you are stuck without warning. Best of luck!
has engine been damage
No revving your engine dosent damage it.
Yes, it can damage the engine.
damage engine no.. will the engine run no.
Well I really have no idea what a ldv is, but if your timing belt breaks and your engine is an interference engine there will be damage. If it is not an interference engine there will be no damage.
On an interference engine the pistons can hit the valves. That will cause severe internal engine damage.
drill it out with a power drill
No - a small amount will not damage the engine, though may cause it to run badly. However, a larger amount can cause serious damage, and the tank and engine should be drained.
NO, it will not damage the vehicle engine by turning the heater ON before the engine has warmed up fully.
if the piston breaks that is engine damage.