I have a vw polo 6n 1.6 litre which recently broke the timing belt. So I'm eager to know if it might have bent some valve or either if it's a non interference engine and i can just fit a new timing belt and run the engine. 

Would need the engine code to be sure...

 

1.6 petrol engine (code EZ )in a mk2 Golf before 1988 was none interference

(used by German army as 3 cyl engine with 4th cylinder as pump to deploy pontoon bridges so very reliable) but newer engines are higher compression so very likely to interfere. 

 

Did it break at speed or just on starter motor?

 

If you can fit a new belt with correct timing and turn the engine twice over with a socket on crank pulley (spark plugs out) with no resistance then it may not have bent valves.

 

If resistance skip to 'Bad'.

 

A compression tester in each plug hole in turn, and crank 6 or so times and measure pressure as roughly same in each cylinder will then prove there's no damage.

 

Bad:

If resistance or uneven pressures, then cylinder head off and inspect the piston crowns for impact, and edges of valves. To check stem straightness you can do a drop test of an oiled valve spun in its own valve guide with head upside down, without camshaft, cotters, or stem seals. It should spin and lower slowly.

 

I'd expect something to have seized and stripped teeth from the belt, rather than the timing belt to snap. Bottom crank pulley cog loose or water pump seized are possible culprits.

 

Or a belt tensioner may have worked loose (never seen this).