math q's...

[dan_c]

so... has anyone done this?
take an m103, an om603 crank, and m104 2,8 con-rods, bore down to 91mm, port the head.... and u get the m103 3,3 with a 8.3:1 comp!
i did use the search tool (in vain), but did anyone fit the diesel crank in the block?

[Ortolan]

I tried this with both 3.0L M103 and C36 rods, it doesn't work. I recall that 2.8 rods were actually longer than the 3.0L rods. The problem is that the pin bore on the piston must be placed much higher up to compensate for the additional stroke. I ended up using the C36 crank (same as OM603 crank) and Oettinger pistons. You will definitely need to make custom pistons if you want the crank to work in the M103 block.
Search through my previous posts if you want more information on this.

[dan_c]

thank you for youre reply Ortolan. I did look into youre thread, and also after a long sleeples night i found these only facts about the 3,2 and 3,3 conversions:

[dan_c]

and some more

[dan_c]

custom pistons are in order, both to suit the 91mm bore, and to bring the pin closer to the top... but what rods go to 84mm travel?
the 350d crank and rods go over 90mm travel
the 300d gives the 84... or so i think...

[Ortolan]

If you are having custom pistons made then you can retain your stock 3.0L rods.