E30:Details of my Killer engine

[tom.murphy@xxxxxxxxxx]

     Hello BMW Experts!  I have recieved a few congratulations on finishing
my engine
project, and a few inquiries as to what I did to get such a powerhouse.
Thanks for the kind notes!
     I wanted hi power with a streetable tune, which would pass pollution
tests.  I started with my old M20B25, got a used diesel crank, and fitted
new JE forged pistons using my stock connecting rods.  If you do this, get
a crank which doesn't need any journal work, and save that money!  My
piston maker asked if I would shorten the rods 2 millimeters, so that he
could make
pistons with enough room above the top ring.  I said ok, but on second
thought I wish I had stayed with the stock lenth rod, and put a ceramic cap
on the piston to keep the rings cooler.  Same money, more power?  Results:
2.821 liters, CR of ~ 10.2:1.  86 x 81 mm, bore/stroke.
     The machine shop lightened the rods slightly, (which I liked from past
2002 rebuilds), and I smoothed the rods and crank myself (the hot-rod books
say a lot of oil weight can hang onto rough rods and cranks).  All rotating
and reciprocating parts were balanced to within one gram(?).
This all goes back to a lightened flywheel.
     The head got a porting job by Long Island's best, Eric K. (NY).  I had
my cam reground to a 272 degree spec. (don't know where it is measured!),
smoothed and matched the intake runners to the head ports, checked for
gasket interference (found some), and minimised the throttle body central
shaft.  I got a good deal on a Stahl header from bmwcca member #2, and had
it ceramic coated, inside and out.  Then I plunked down $ for a Supersprint
muffler.
     I coerced a vendor into selling me the adaptor needed for a K&N cone
filter, but ordered the cone on my own in order to get a bigger one than
the kits were offering.  I reused the back part of the stock air filter
housing, cut off the front, and used aluminum sheet to complete a heat and
turbulence shield,  To get some air packing effect, I cut out some of the
plastic grill around the headlights and the plastic behind the lights.
     Topping all this off, my last purchase was for a custom Garrett
Integrated Automotive (NJ-PA) ECU chip.  Redline: 7100 rpm.
     The car runs great, being much faster than my '79 Euro 635, and
probably faster than a stock E36 M3.  I can floor the gas at 2000 rpm and
keep it down, with no knocking, flat spots or surging.  Idle is just a
little bit lumpy, but hardly noticablely different. I still get that great
'on cam' rush at about 3800-4000 rpms, but don't need to be there for
power. The supersprint is only a little more noisy, mainly when starting
off, but a I do have a bit of that header 'rattle' (for want of a better
word).  No tickets so far, doing (moderate) street racing whenever I can!
               Murf '87 328is '79 635csi      BMWCCA 79550

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End of bmw-digest V9 #149
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