How to: Tell what head an M20 has, the 2 second way.

[MattAvino]

Very interesting, my motor or head has under 200k then.

[reelizmpro]

The m20b25 I just pulled from my '87is has the '2.5' over the '2.7' stamped on the head. So has the head been replaced in the past?

This or the entire engine.

[MattAvino]

so if you have an 87 325i with a "2.5/2.7" embossed head and torx headbolts you know they were changed at some point.

The m20b25 I just pulled from my '87is has the '2.5' over the '2.7' stamped on the head. So has the head been replaced in the past?

[cabriodster87]

I just found that i have the AMC head. It's like my baby is sick now.

BMW how could you let this happen?

http://www.r3vlimited.com/board/showthread.php?t=232555

[Herr Faust Schinken]

Yeah yours is an oem head the 885 casting mark on the sides proves it

[Earendil]

So I always thought my head was the AMC head because it did not say "2.5" on the casted knob above the 2nd cylinder exhaust port. However, I still have the knob (just with no numbers), and I have the circle with the indentation above the 3rd cylinder exhaust port. My head is not original, the PO snapped the timing belt in 2003 and it was replaced with a "remanufactured" head according to the service records. Any thoughts?

This is the first time I'm hearing about this AMC head business. I have a "stock" motor in a 325i with no receipt history. Mine looks like yours. I'm wondering where this fits inter the picture? If we figure this out, anyone would be welcome to use my picture as an example.




EDIT:

I almost forgot. I tore this head down two years ago and took pictures. This is what the backside says. I think it might be. bMW head ;-)

[German Audio Specialties]

I have a M20B23 in the shop now, with a known original head. I will snap some pics of it soon

[TurboJake]

So I always thought my head was the AMC head because it did not say "2.5" on the casted knob above the 2nd cylinder exhaust port. However, I still have the knob (just with no numbers), and I have the circle with the indentation above the 3rd cylinder exhaust port. My head is not original, the PO snapped the timing belt in 2003 and it was replaced with a "remanufactured" head according to the service records. Any thoughts?

Purely based on the casting surface texture, I'm inclined to say that your head is a BMW head and not an AMC. Every AMC I've seen has a very rough surface, whereas yours is rather smooth and appears to match the valve cover.

But if you decide to look and find out what it says behind the intake manifold, let me know. I haven't seen that before.

[jw 325ic]

So I always thought my head was the AMC head because it did not say "2.5" on the casted knob above the 2nd cylinder exhaust port. However, I still have the knob (just with no numbers), and I have the circle with the indentation above the 3rd cylinder exhaust port. My head is not original, the PO snapped the timing belt in 2003 and it was replaced with a "remanufactured" head according to the service records. Any thoughts?

o/t, you can replace that spark plug wire loom for like $10 from the dealership....

[Boise]

So I always thought my head was the AMC head because it did not say "2.5" on the casted knob above the 2nd cylinder exhaust port. However, I still have the knob (just with no numbers), and I have the circle with the indentation above the 3rd cylinder exhaust port. My head is not original, the PO snapped the timing belt in 2003 and it was replaced with a "remanufactured" head according to the service records. Any thoughts?

[Herr Faust Schinken]

Thanks for the info turbojake.

[TurboJake]

I just checked my head I have the little round thing but not the 2.5 /2.7 does this mean I have the cruddy amc head here's a picture

I don't think so, you can now see that I have added the info for an AMC head. You sir have an 885 head with that casting mark just machined or ground off. That casting circle does not exist on the AMC head at all above the #2 cylinder exhaust port.

[Herr Faust Schinken]

Thanks looks like I'm gonna haft to pull the manifold off to check

[craiggroves91]

I just checked my head I have the little round thing but not the 2.5 /2.7 does this mean I have the cruddy amc head here's a picture

I'm not a head expert, but it almost looks like they grinded the badge off

[TheTacoMan]

Or, if it does not say anything where you have "2.5/2.7", like mine, then it is the dreaded AMC head. Noooooo....

Good post, this would have saved me a lot of searching a while back. Keep up the good work!

It just says 2.5 there
Also it does have one spring per valve I checked just in case I had an I head. Also further inspection I found it was an 885.