M20 bent valves. Options?

[jmc330i]

I got a 325i touring last year after the owner had changed the cambelt himself and got 6 bent valves for his troubles.

I'm just looking at sorting the head for the moment, so other than the valves, what else would I need to replace?

[craigieeb]

I would check the rockers,
if they haven't snapped, there will probably be a crack somewhere

[Rav335uk]

I would look at the Rocker shafts too.
When my timing belt went, I bent 8 valves, 5 rockers, and 2 shafts.

[reggid]

makes sure guides are good as you wont get a good VJ without this when you use new valves

[HairyScreech]

I have plenty of spare stock valves and rockers here if you need a few. (wiltshire/somerset boarder)

If you need an assessment of the bits once the head is off let me know, pretty familiar with how/where they fail.

[jmc330i]

Cheers guys, that gives me some things to look at when I strip it down.

I have plenty of spare stock valves and rockers here if you need a few. (wiltshire/somerset boarder)

If you need an assessment of the bits once the head is off let me know, pretty familiar with how/where they fail.

That would be good The head is already off, but I've not looked at it too much yet.

Once I know how the bits have faired I can start planning the next step for the M20.

[moapys]

Hi - I just suffered an "interference situation"; not a belt breakage - but an idler shaft shearing...same effect - valve/piston collision.

My question: Beyond the usual bent valves (all intake <?>) and broken rockers (all six intakes <!>), I have one badly nicked piston top. I'd say that the depth is as much as a 1/16" in a few locations.

If I grind/polish out the high spots, is there much of a chance of "burning through" the injured piston? Thanks for your opinions.

Paul

[HairyScreech]

Without seeing some pictures its hard to say.
It all depends where and how much grinding would be needed.