Saturday, December 3, 2011

BMW M44 Engine to Create a BMW S42 Euro Racing Engine Replica

  • M44 block bored out to 86mm to accomodate the Euro S50b30 pistons

Pistons: Left M42, middle S50 (decked), last STD S50
  • Euro S50b30 pistons decked 3.8mm and pocketed
Pistons: Left M42, middle S50 (decked), last STD S50

  • M44 connecting rods with custom small-end bushes....M44 rods are lighter than M42 connecting rods and contrary to popular belief they are forged)

  • Stock M44 big-ends and main bearings

  • Fully balanced bottom-end

  • Lightweight flywheel

Here's the rods: Left M42, next M44, next M47, las
  • M47 (E46 320d) crank with 0.5mm machined nose so the pulleys fit   NOTE - One important thing about the crank swap... The M47 keyway is closer to the snout of the crank than for the M42/M44. The stock key location on the M47 crank engages about 1/8" only of the M42 timing chain sprocket. You need to either have another keyway slot cut into the crank (best) or extend the key father back so that it engages more of the sprocket..."There's no replacement for displacement." This diesel engine crank increases the stroke by 8mm and displacement by 8.5%. You'll increase torque as well with the now longer 88mm stroke.

This high output configured engine has a Stock M42 head, so far, head work and Cams would obviously increase HP in addition to these significant bottom end upgrades.

  • AFM to 3" MAF conversion (E36 328i MAF) the engines found on E30's use a MECHANICAL component called a AFM (air flow meter) to measure the amount of air going throw the intake. In this way, the computer can calculate the amount of fuel to inject in each cylinder. They stop using this AFM component around 1992. While there is some dispute regarding when the AFM was removed from production and when the MAF began [it is thought by some that BMW didn't switch to the MAF until the M44?], they replaced the AFM with a MAF (mass air flow meter) which is an ELECTRONIC component used to measure the amount of air going throw the intake.
 This is the diagram for the AFM to MAF conversion.

  • 80 degree thermostat
  • Custom 6mm duraform spacer gasket for intake manifold (keeps intake mani ice cold)
  • Stock M42 header, so far
  • TB water line delete
  • Euro M3 injectors
  • Fan delete mod
  • Dastek unichip
  • CAI
  • 11,6:1 compression
  • Current rev limiter @ 6750rpm

Future Modifications:

  • Euro M3 ITBs
  • Euro M3 solid lifters
  • 34mm intake valves
  • Gasflowed head
  • Bigger cams (don't know how big yet)
  • Custom header (4-2-1 48mm runners)
  • Up rev limit to 7500rpm

These S50B30 throttles bodies will be later fitted to another cylinder head. Still need to get another M42 head which will be gasflowed, bigger valves, better valvetrain, solid lifters and custom billet cams. The intention is to use the first two and last two throttle body sets. The fit to the head is like the ITB:s was intended for the M42. Additionally, S50B30 plenum chamber, ram tubes and rubber boot for the MAF.  The builder will cut cylinders 1 and 6 off and weld it closed. Its made of aluminum.

cut and finished throttle bodies

source -


  1. Super tare. Si pe mine ma bagate gandul ca anul ce vine sa imi fac unul . Poate ma consiliezi daca nu ma descurc ... Nu inteleg foarte bine limba engleza...

    M-am gandit mult la un stroker de 3,1 litri de M50 si mai pot sa-ti dau si eu unele sugestii si linkuri utile avand in vedere ca chiulasele de M42 si M50 impart cam aceleasi piese componente... Am gasit axe cu came de 274 de grade noi de rally cu 1000 ron pt M42 , poti sa pui supape mai mari de 34 mm pe care le-am gasit la 8 ron noi etc etc... Facem schimb de experienta daca vrei...

  2. De asemenea poti ridica linistit turatia si acum in 7200 de ture avand in vedere ca axele tale sunt de 252 de grade. Eu am limitarea in 7200 acum pe M50 ( cu axele stock 240/228 ) si precum probabil stii axele cu mai multe grade au si lobii putin mai lungi deci supapele sigur nu iti vor intra in acel efect de plutire...
    Tacheti mecanici deasemenea poti lua noi cu 1000 de ron... Sigur avem ce discuta daca iti face placere...

  3. Look here :)