m20 valve to eccentric contact area

[e30davie]

Righteo well I finally got a chance to fix this up last night. Poor old bmw has been sitting for a few weeks unloved due to a new daily driver...

Anywho, got it all apart, set it up to adjust cylinder 1, and i couldn't actually get the eccentric to tighten up at all on 0.25mm anywhere I put the eccentric. Flipped it over and no difference.
'
At my whits end i grabbed an eccentric off a spare head (unknown km's) put it against the eccentric off this head and this eccentric didn't appear to have any major noticeable wear. Though i didn't measure it was just by eye. but they looked pretty much the same...

So I put the eccentric off my spare head in, and immediately I was able to adjust it properly to 0.25 with eccentric in the middle of the valve like it should be, and like the other 11 valves....

So it seems i guess the old eccentric was worn out. I had read rumours of "flat spotting" on the eccentrics but i was looking for a significant spot. it seems the flat spotting is significantly less wear than I was expecting. Anyway here is a photo of the naughty apparently flat spotted eccentric. maybe it is worth buying 12 new ones? the rest adjusted fine, it was just this one.

Also i made a spanner to take off the fan and took the radiator fan out with the shroud and that made it easy to put my socket on front of the engine.

[TobyB]

If you flip the eccentric over, it will change the location
of the adjustment hole.

That might make things easier...

t

[Lugnuts]

Take the spark plugs out, put it in 5th gear, shove car back/forward until lobes are in the right place. That's how I've done it in the past.

[zaq123]

ok ok ok ill pull it out and turn it around.

Here is a fairly dumb question. How do people usually turn over the engine by themselves and watch the valves when doing this job? Obviously get a spanner on the front of engine but with the AC and all the shit in the its not easy to turn over engine and watch the valves. I can turn the engine from below...but then i cant see the valves....

I've only ever done it with a friend and have always cheated and jacked up a rear wheel an just got them to turn the wheel with gbox in gear.

there is plenty of room to do it from the top, even with hood still attached. you can place a card board or something on the inside of the radiator, allows you not tobe extra careful and keeps your tools from the radiator fins.

[e30davie]

I bent up a bit of wire and was able to use the hole facing down to further adjust. Dont underestimate my ability to fudge things to make them work when clearly they shouldn't. To be honest my back was sore and i was sick of leaning over. I kinda hoped it was good enough, and yet, here we are:)

[zaq123]

Realised last night that the hole for the Allen key adjustment tool is only on one side though so they only go in one way.

haha. Well the hole has to face up otherwise you won't be able to just it. I guess you can say it goes one way. How did you set the clearance if the hole is facing down? Would the inability to set the clearance kind of signaled that something is off?

[e30davie]

ok ok ok ill pull it out and turn it around.

Here is a fairly dumb question. How do people usually turn over the engine by themselves and watch the valves when doing this job? Obviously get a spanner on the front of engine but with the AC and all the shit in the its not easy to turn over engine and watch the valves. I can turn the engine from below...but then i cant see the valves....

I've only ever done it with a friend and have always cheated and jacked up a rear wheel an just got them to turn the wheel with gbox in gear.

[nando]

I was going to say it's in backwards, which is why it looks wrong.

[e30davie]

Realised last night that the hole for the Allen key adjustment tool is only on one side though so they only go in one way.

[e30strokr]

.. that's why they're called eccentrics

OK.. he just need to flip it and it will be normal, also the hole has one side concave

[kronus]

I just did my eccentrics and the hole is offset.....

.. that's why they're called eccentrics

[e30strokr]

It was getting late. I got the feeler gauge between the edge and the eccentric and did my best to set it to 0.25mm. Felt weird sure but it ran good. I'll have another go tomorrow:)

I just did my eccentrics and the hole is offset..... that would explain the "over rotated"

[e30davie]

well that possible...but doesn't make any sense why would you do that. Over rotated eccentric will change your valve clearance. They only reason to have them loose is to set the clearance. If your clearance is set to spec'd 0.25 and your eccentric is on the edge like that, something is off.
What did you set the clearance to?

It was getting late. I got the feeler gauge between the edge and the eccentric and did my best to set it to 0.25mm. Felt weird sure but it ran good. I'll have another go tomorrow:)

[zaq123]

I had a bit of a play on the spare head i have. I think iv'e actually over rotated the eccentric.

well that possible...but doesn't make any sense why would you do that. Over rotated eccentric will change your valve clearance. They only reason to have them loose is to set the clearance. If your clearance is set to spec'd 0.25 and your eccentric is on the edge like that, something is off.
What did you set the clearance to?

[e30davie]

I had a bit of a play on the spare head i have. I think iv'e actually over rotated the eccentric. I reckon if i take it back a half a turn ill get the same adjustment but the thing will be in the middle of the valve.

I'll pull the cover off tomorrow after work (its late Monday night here)

The only thing they they did to the head was new exhaust valve seals, rest was untouched. They just said the rest was in good/great condition. The engine purs along, so quiet now, i think we are all good, i just stuffed up this first valve.