M20 Heads

[Plumberpat]

I have a M20 with 335,000km (208 miles). I tried to set the valves and found that I’ve run out of adjustment on two exhaust valves. It’s an AMC head and I’m wondering how much real world difference there is between the 885 and the AMC. 885’s aren’t that easy to find around here (Vancouver Island), so I’m wondering if I should just have the AMC rebuilt or spend the extra to buy a 885 and then rebuild it.
Thanks,
Pat

[superj]

whats an amc head? I have never heard of that. that eccentric wears out on the rocker arm though, it gets a flat spot. try putting another two rocker arms for the ones that won't come in and see if the adjustment comes back in.

you can have it rebuilt but those I heads are getting expensive and hard to find, everywhere.

[hotdish]

I think you probably want to get an 885 if you're going through the trouble of rebuilding an m20 head.

whats an amc head? I have never heard of that.

Aftermarket replacement head casting

[superj]

ohhhh, ok. thanks /\

[e30oe21]

I have a M20 with 335,000km (208 miles). I tried to set the valves and found that I’ve run out of adjustment on two exhaust valves. It’s an AMC head and I’m wondering how much real world difference there is between the 885 and the AMC. 885’s aren’t that easy to find around here (Vancouver Island), so I’m wondering if I should just have the AMC rebuilt or spend the extra to buy a 885 and then rebuild it.
Thanks,
Pat

From what I've read on the internet, stock to stock the BMW casting is better. If you are going to port, the AMC casting is a little better due to a little more material and room to port.