m20b20 head on an eta?

[notoriousbij]

I just bought two euro model e30s, a 323 and a 320. The 323 was rearended but runs great while the 320 has a burnt valve. The plan is to put the 323 motor into the 320. But, I also have a 325es. I have heard of bolting the 323 head onto the eta block, but was wondering if the 320 head was the same? I would use the 323 head, but the motor runs awsome the way it is, while the 320 head needs to be rebuilt so I would have to tear that motor apart anyway. Does the 320 come with the 731 head?

Many thanks.

[rs4pro3]

check the part number on the intake side above the ports, if it ends in 731 then You'll gain quit a bit of HP bolting it onto an eta block. If it's not that head it's not worth bothering.

[AdamF 88iS]

'731' is a casting number, not a part number.

The ETK lists the 320 and 323 as both using the same head by part number (11 12 1 277 753).

[decay]

they do use the same head casting, but the 323i cam is a bit hotter from what i understand.

also, you're going to want an i intake manifold & tb to go with that as well; if you check realoem you'll see the gaskets for the b23 and b25 are the same.

i would consider finding some slightly-higher-rated low-impedance injectors to throw in at the same time as well.

[notoriousbij]

Thanks for the info. I will check the part numbers shortly. But, in order for this to work correctly, I need a 325i intake? It would be sweet to use the one that is on the 320 motor if it would work. If not oh well, can't win them all. Thanks for the help.

[notoriousbij]

I finally got the motor apart enough to see the casting number, and the 320 head is the 731. :D I had just one more question though. Does anyone know if the intake for either the 323 or the 320 is the same as the 325i? They are both i models, but I am not sure if they are the same. Your thoughts are most appreciated.
Thanks

[rs4pro3]

the 323i manifolds I've seen have smaller runners then the 325i

[decay]

the 323i manifolds I've seen have smaller runners then the 325i

i wouldn't be surprised by that at all.

but what's important is that the gaskets are the same for the 323i and the 325i-

so if you wanna slap that shit on your eta block, find and use an i manifold/TB is my advice.

[Court M3]

notorius what are your plans for the 323? PM me mgith need some things from you if you decide to part is out ;)

[Madhatter]

The heads are identical.

320/323i inlet manifold are shorter than the 325i item, the plenum is also smaller.