I thought this would be helpful for everyone and to be added to by everyone. This is probably the most experienced group of people I have run across in modifying these engines. A thread for the other engines also would be good.
I for some reason can not upload some documents I scanned on compression ratios. I have quite a bit of other stuff printed out of WIS on the engine for full spec.
It has compression on all the variants by model. It shows the the 104.992 having 9.2:1 compression except the e36 models at 10.5:1. I will try and get it loaded when I can. I currently can not upload anything for some reason. I will scan some piston rod documents also. Maybe get valve sizes cam data etc.
MAG58 had cc on the head and the gasket to be added.
I also was going to add some specs from the CP form for my pistons.
The compression height is 1.225
Bore is 3.5433. That is a cleaned up stock bore. Basically between standard and replacement size.
Dish depth is -0.05
Mercedes specs: 104.942
The stock bore spec is 89.9-89.906 Piston is 89.873-89.879
to 89.912-89.918 Piston is 89.885-89.891
Rods are 148.995-149.005 center to center of bores.


I will add more later. Easier to scan and upload.