Re: 318is engine question

[Herman Chan <hermanc2@xxxxxxxxxx>]

> Now the engine. I'm trying to decide which engine conversion to do
> on my 2002 and am leaning toward the 91, 318is engine. My questions
> are: Is a 91 the best year model engine for the conversion? What's
> the highest horsepower rating stock for this type engine, and if
> tweaked right, what's the highest HP I could get using one of these?
> Any input would be appreciated.

Barry,

The profile gasket failures that afflict engines up to circa 11/93
production should be a prime consideration, but there were evolutions along
the way:

- - the '91/E30 version of the M42 has a simpler single stage intake manifold
and a different oil pan than the later E36 versions

- - the '92-'94/E36 version M42 has the DISA two-stage intake manifold, M1.7
DME, and airbox similar to that used in M20 sixes.

- - the 2/94 (I believe) and later M42 have M1.7.2 DME, integrated coil pack
and a bigger, squarer airbox.

- - the M44 that made its first appearance in the '96s has fractionally
greater displacement and torque and some revisions to the valvetrain, but
is saddled with OBD2 and EWS.

The changes in the intake and displacement were meant to improve torque,
but there's only so much to be had from ~1800cc.  At some point, the
crankcase breather hose nipple was moved from the front to the back of the
valve cover.

Physical contraints may dictate which combination of parts you can use; I
can't say, never having done it;  I only wanted to point out the
differences I was aware of.  There's a gentlemen from So. Cal on the
digests who has personally done the conversion.  He can probably pick up
the specifics.

Herman

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