E30 2.7i Build Advice

[Guest E302.7T]

Hey,

Just wondering if doing the 2.7 stroker build on a e30 323i using the 323i head and eta block is worth it and what components do I need. At the moment I have a 323i m20b23 engine and the eta block, the aim is have something with a little more go while I save for a turbo conversion.

Any advice/help would fully be appreciated, please excuse me and my dumbness as I am new. Thanks

[antil33t 90]

Have a good read of this (if you haven't found it yet)

http://www.e30tech.com/forum/showthread.php?t=48288

It's quite big, but it's a good place to start.

[e30ftw 394]

Would go with the 885 (325i) head if you plan on going turbo down the track. Bigger ports etc. Lower compression.

Definitley worth it.

[Guest E302.7T]

Have a good read of this (if you haven't found it yet)

http://www.e30tech.com/forum/showthread.php?t=48288

It's quite big, but it's a good place to start.

Cheers thanks alot just another question to put out there if i have the 323i head 731 and the eta 2.7 block do i need to get the clearances checked ? or should it be alright

[Guest E302.7T]

Would go with the 885 (325i) head if you plan on going turbo down the track. Bigger ports etc. Lower compression.

Definitley worth it.

Yea but then don't I need custom pistons etc etc?

[antony 0]

No, You need the block decked a few Millimetres, M20B25 pistons, M20B20 rods and a Vernier pully on the cambelt.

Or you could leave it as is, and just bolt the 885 head on here. All detailed in this link...

another 2.7 link.

Edited June 15, 2010 by antony

[Guest E302.7T]

No, You need the block decked a few Millimetres, and a Vernier pully on the cambelt. Or you could leave it as is, and have a really really low CR.

another 2.7 link.

Sweet thanks for that. would the cr be just right for turbo?

[antony 0]

Hey, I've edited my previous post.

Your CR will depend on what option of head/pistons you go for, but I would try get it as low as possible.

[e30ftw 394]

Which ETA block have you got? What year car?

If you have the later 10.2:1 pistons the 885 head will drop compression to 9.5:1

If you get a thick steel headgasket you can dropper lower still..

[Guest E302.7T]

Which ETA block have you got? What year car?

If you have the later 10.2:1 pistons the 885 head will drop compression to 9.5:1

If you get a thick steel headgasket you can dropper lower still..

f**k not sure I think its the later one 1984? Still not very sure if I should do the stroker build or just get oversized pistons but where would that leave my capasity if it was a 2.3

[pureboiracer 0]

dont f. around with a 2.3 and oversize pistons and all, imo the best bang for buck would be to put together the 2.7 and throw a turb at it.

[antony 0]

The piston's on the early block are flat on top, and the later have a slight dish.

Or if the head is still on it...

Early Etas up until Sept. 1985 had a compression ratio of 11:1. The blocks of these engines is stamped 27 6KA. From 9/86 the compression ratio was dropped to 10.2:1 and these engines are stamped 27 6EB. These numbers are stamped above the main engine number

[e30ftw 394]

If its the early one the top of the pistons usually stick upwards, others have a dish as said.

http://www.bmwccn.no/rogaland/Mahle_m20.html

Look at last 2 for reference.

[Guest E302.7T]

dont f. around with a 2.3 and oversize pistons and all, imo the best bang for buck would be to put together the 2.7 and throw a turb at it.

So fully not worth the fukin round?

[Guest E302.7T]

The piston's on the early block are flat on top, and the later have a slight dish.

Or if the head is still on it...

'

No head just the block and yea wouldnt have a clue sorry for being a noob

[Guest E302.7T]

If its the early one the top of the pistons usually stick upwards, others have a dish as said.

http://www.bmwccn.no/rogaland/Mahle_m20.html

Look at last 2 for reference.

The block is 1985, the pistons are 10:2 CR and The pistons were all measured and were very close to spec 83.98 so may have been replaced. Slight lip on the bores but in very good condition.