M50 stroked with M54b30 rotating assembly

[V-technician]

Hope im posting this in the correct section.If not,admins please move to correct section.
I'm sure this has been covered,still reading through the threads though

So want to stroke this M50 however engineering says block needs to be bored 0.5mm oversize.
Still trying to source oversize 330i pistons-waiting on suppliers.
The BMW guys here advised using the opel superboss pistons-2.0 XEH motor.

One of them gave me a new piston as a sample for testing/measurements.
Piston size 85.97mm
Compression height on piston is 30.43mm
Wrist pin is 21mm-will have 2 custom make small end bushes 2 fit onto rods.
135mm m54b30 rods
Problem is when doing calculations the piston protrusion is 0.18mm
And compression ratio is 13.13 with this piston and 1.75mm head gasket and 34cc on stock m50 head.
This will be an n/a build and want it to be a higher compression build but 13 is way too high.
Any1 run these pistons on this stroker setup or any advice on what piston or rod to use?
Thanks in advance

 

[KarshS]

@Nikhil

 

[V-technician]

@Nikhil

@Nikhil sum info?

 

[PaKiMoNSTeR]

Also keen to learn. There seems to be a lot of difference recipes on how to stroke the M50's.

 

[Nikhil]

Dont complicate it, Get an M54B30 crank and conrods and then get a set of aftermarket m54b30 forged pistons with an off the shelf compression ratio that is offered. That way valve clearance ect is sorted already.

Everything else stays stock and you have higher displacement and more power reliably using a full oem setup with aftermarket pistons

 

[V-technician]

Thats a very sensible logical response.
Crank and rods sorted.
Wiseco all that they offer, comp heights are 31.6 to 38.2mm.
Might have to go with custom pistons.
Stock M54b30 pistons are 28.32mm comp height.
Cannot source oversize M54b30 pistons.
Not to worried about minimal piston protrusion but will do sone calculations regarding comp ratios.
Thank you

 

[PaKiMoNSTeR]

Thats a very sensible logical response.
Crank and rods sorted.
Wiseco all that they offer, comp heights are 31.6 to 38.2mm.
Might have to go with custom pistons.
Stock M54b30 pistons are 28.32mm comp height.
Cannot source oversize M54b30 pistons.
Not to worried about minimal piston protrusion but will do sone calculations regarding comp ratios.
Thank you

What does this equate to in CR terms?

 

[V-technician]

Well with stock M54B30 rotating assy in an M50 with stock M50 head looking at 10.13:1 comp ratio