cylinder head wow's

[Vincenzo]

So we sent the cylinder head away because we bent a valve when we put the timing belt on wrong. When we got it back all the roccers were put on not in the order that they were taken off (we numbered them) Because our ex mechanic friend said that the roccers are different sise for each valve, is he right? So we put the cylinder head back on and got the timming sussed so it was spot on because we had stuffed up befor and we were 100% on geting it right, when we went to ajust the valve clearence on No. 6 the valve spring came up to much so we couldn't ajust it. So we took the cylinder head back off and the No. 6 valve was snapped off just a little way up the stem. WHAT THE F*#k. so we are sending it to the guy that fixed the cylinder back today and he is going the put the rocccers back in the right order and we are going to put a new valve in. Does anybody know how we can avoid this problem happening when we put it back together again, because it has now been off the road for 12 weeks and we are getting anoid! Thanks Vincenzo

 

[vlad]

To my knowledge, a rocker is a rocker for a e30 engine, (and probably for any other BMW engine). The only difference that I can possibly think of is intake vs. exhaust, but that isn't the case for the e30. The only reason I can think that you would need to number the rockers is that they could possibly wear less if placed back in their original orientation. If they aren't in their original orientation, it could be possible for them to wear just a little more to seat into their new location.

The only reason that I can think that you snapped a valve off is that the head may not have been in the correct timing to the engine when you set the head down, hitting the piston top. Either that or you may have hit something else when trying to position the head.