85 e30 Block Use

[MurphinDC]

I'm gathering parts for a rebuild and have a line on a full 1985 e30 318i motor.  I am really only interested in using the block and I have searched the archives and it appears that this block would be usable, if I swap the crank, pistons and rods with 2.0 parts.  Can I get the experts here to confirm that my assumption is correct?  Any other items of importance I should be aware of using this block?  My plan is to use an e12 head.

 

Thanks

Murph

[TobyB]

The only thing to confirm is that it has all 

of the accessory mounts you need-

and that includes the engine mounts!

The bosses should be there- they may just not be

drilled and tapped.  Easy enough to fix while everything's dirty.

 

Yes, it should work just fine, and be about 10 lbs lighter

while also being a bit stronger. 

 

t

 

 

[tzei]

Rods are same lenght so you can use them.

I have to disagree about block being stronger as i have encountered couple cracked in normal use. Maybe i have had bad luck.

[Tommy]

It is funny how the strength conseption is different globally. Here in north-east older and heavier blocks are always referred as the strong ones.

[TobyB]

I might be misrepresenting 'strength'- the later block is more rigid,

but since it has less metal, it may indeed crack more easily.

Certainly has less material, and may be less ductile.

 

Now that y'all say it, I've seen later bores cracked, too, and so far

the only earlier one I've seen... well, I did that.

 

t

yup.  3 laps without coolant.  What could go wrong?

[Preyupy]

I have found that the later blocks have a much more consistent cylinder wall thickness.  If I am going to try and bore a block to 92mm or larger I always have them sonic inspected to make sure there is enough wall thickness.  The early blocks have shown to have some core shift in the castings and they can get a bit thin in places if you are not careful.  At anything under 91mm I would still choose the later block just because of the weight (for race engines).  If you are cracking a block something else is wrong.  

[Oldtimerfahrer]

Is the block itself a straight swap for the earlier 2 liter block? I picked one up a few years ago for nothing and have been wondering if it's worth keeping. I think I have an E21 vintage M10 block currently...

Andrew

[Preyupy]

I think there are a couple of bosses on the blocks that are different (Mounts for A/C compressors, and brackets)  You will just need to have a look and see if the ones you need are on the block you are trying to use.  

[MurphinDC]

Thanks for the help, but the deal fell through.  

 

Murph