M20B23 motor and Getrag 5 speed from a 1985 E30

[Switch]

yeh, i think i know where i might be able to find one.. sry for the common sense (about displacement and compression, ) i heard somewhere (proby here) that the tranny that comes with the euro 323 is the dogleg tranny (close ratio fifth) did all the 323 trannies comes with this factory?

[code-]

i heard somewhere (proby here) that the tranny that comes with the euro 323 is the dogleg tranny (close ratio fifth) did all the 323 trannies comes with this factory?

Nope, very few

[bkelsey86]

mine didn't come with it :(

[Switch]

how would u tell (i'm guessing it says something on the actual bell housing?)

[bkelsey86]

thst and your gears would be in different spots with all odd number being down and all evens being at the top of the pattern.

[Madhatter]

thats kinda cool... so its basically an 2.5 head with a stock higher cam...

it would be more correct to say it's an eta head with i port passages. valves are the same as an eta, but intake manifold gaskets are the same as an i.

so.. why won;t it just bolt onto an eta? (or super eta?) low compression issues?

it will bolt up to an eta, super-eta or i blocks are what it's not compatible with.

compression ratio of the 731/eta combo has been reported here at ~9.8:1.

No, not really The eta head is the earlier E21 casting, that is why it still has the injector recesses (the K-jet injectors sat right into the head), the E30 323i head (731) is a newer revision, it isnt the same.

They have valves 2mm smaller than the B25, but they run larger valve lift and duration as standard though.

It will work with super eta or I blocks, the problem is the pistons end up smacking into the head because of the domed dish setup they have. You could use any larger bore block as long as you matched pistons.

Gearbox with the engine will either be a 245 or a 240 getrag, neither are dogleg close ratio boxes.

B23 Head
B27/B25 Block
B27 (eta) Pistons and Crank

That is the combination you need. The simple reason why the B23 head is a better alternative for the stroker is because of compression ratio, B23 head results in a higher comp ratio than if you were to use the B25 head. Power is actually up on the same stroker conversion too (using standard components).

[ultima]

Or you can search for a Euro b25 head. They yield higher compression than the U.S. counterparts...9:8:1 I believe...

[Switch]

soo.. madhatter, ur saying (i';m sure i am just repeating you.. sry)


323 head w/ eta..... (not super or i block) and that will be it? lol seems to simple......

[decay]

It will work with super eta or I blocks, the problem is the pistons end up smacking into the head because of the domed dish setup they have.

yes, that is what i meant by "not compatible".

[Madhatter]

Or you can search for a Euro b25 head. They yield higher compression than the U.S. counterparts...9:8:1 I believe...

The heads are the same, the pistons are different.

[Madhatter]

soo.. madhatter, ur saying (i';m sure i am just repeating you.. sry)


323 head w/ eta..... (not super or i block) and that will be it? lol seems to simple......

Not really, im saying you can use any block with a 84mm bore. That includes the 325i and both eta (the standard and the super).

The reason people say you cant use the super eta or 325i block is not because of the block at all, it is because of the pistons. If you use pistons from either of these two they will strike the head, the standard eta pistons arent domed like these two are.

But yes, for all intents and purposes, eta block, 323i head and you are good to go.

[Switch]

niiice lol thanks alot

[Rhys]

This thread has been very useful to me, just picked up a 731 323i head.... now to find a eta block!

[SpecM]

now to find a eta block!

should be easy, people will just about give them away