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Re: 2002 with an M3 crank?
> Another thing to keep in mind wrt to a stroker configuration is an M10 block
> is the rod/stroke ratio. I personally would try using as long as rods as
> possible, if I were doing a stroker configuration. I also agree with Ben,
> its not worth putzing around with increasing the displacement. Finding
> extra cubic inches in a 2002 is extremely expensive, and not cost effective.
Increasing the rod/stroke ratio is what BMW did for the M3 motor. Reduces
rod angularity problems as the stroke length goes up.
Finding an extra 100 or so cc's for the 2.0 is not too difficult, but
anything more gets a bit complicated.
> There's nothing wrong with the stock crank (many good things, IHMO) or
> the stock bottom end.
Definitely not. The only reason any of this is being considered, IMHO,
is to increase the displacement for more torque and power. The stock 2.0
bottom end is immensely strong, IMHO.
> >> After my affair with the pistons not getting sold to me, I figured
> >> I would measure my stroker setup and re-evaluate before I spend $400
> >> for a new set of pistons.
>
> I'd personally put that money into an injection system, or buying good
> valvetrain hardware. (in a performance application)
I'd put the money into tii struts and brakes (didn't you say that you
were still running stock brakes, Fillipo?). Then maybe an injection
system. To do an M3 crank setup, I'd figure on spending an extra $700
or so.
> >I've been looking at this, and am not sure that the gain in displacement
> >from 4mm of stroke would outweigh the increased mass and the trouble and
> >expense to make it all work. Plus, I have a feeling that the resulting
> >motor would be more prone to vibrations and buzzing than a 2.0.
>
> A well balanced 2002 engine is pretty smooth, I think.
Yes, but M3's tend to be a bit on the buzzy side. The M3 uses damped
motor mounts to mitigate the problem. Unfortunately, that kind of
setup is difficult to implement in a 2002.
> >Cheezy. Amazing that the pistons are still strong with 4mm taken off of
> >the top.
>
> And dangerous. Minimum spec for most piston tops is .200" of material. You
> already took off .158" if 4mm was really machined off. (Hey---maybe
> Fillippo's discovered something about weight saving techniques that I should
> know about)
Oops. Brain fade. I rethought this, and it's more like 1mm of material
was taken off of the piston top. I forgot that the old pistons are probably
92mm, 3.5 liter pistons. Which means that they're designed for an 86mm
stroke....
Hope this helps,
Ben