gerald is right -- don't do it (archive)

I have an 88 528e and my roomate has an 86 325e so I do know something about both these engines. The head will bolt up becasue it is an M20 engine, but the compression ratio will be way high and the pistons may actually hit the head.

The standard eta has flat pistons and a corresponding combustion chamber shape to get the correct compression ratio. The 88 528e has what is called th "super eta" engine which is an "i" head with "i" pistons. The "i" head has a more hemispherical combustion chanber and hence the "i" pistons are more dome shaped.

If you put an "i" head on an "e" block without changing the pistons, the compression ratio drops significantly. What you are proposing to do is the opposite and will increase the ratio if the pistons fit at all.

As far as I know, the only signficant difference between a super eta head and and i head is the cam.

If you have any more questions email me since I don't regularly check this board.

Devinder

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