M50 3.0 liter stroker

[blink977]

I'm building M50 3.0 liter storker for my E30.
Have a lot of work done choosing differrent piston and rod combo and finally here's it is:
M54B30 crankshaft
135mm rods
M42B18 84mm pistons
Iron M50B25 block

I'm getting:
89.6mm stroke divide by 2 + 135mm rod + M42 piston 31.65 compression height and I'm 0.45mm over deck and with stock 1.7mm headgasket and piston dish somwhere 5-7cc getting 12.0-11.6:1 compression ratio. al this will be managed by siemens MS40.0. Why? Because I have non Vanos head but really need knock sensors with such a high compression, so the MS40.0 is the only non-vanos management with knock sensors.

I'd like to listen for wise engine builders, maybe I'm mistaken in something?

[Fusion]

Interesting! Never seen the combo.
Any idea on expected power output?
Maybe get a Cometic head gasket to be safe?

[blink977]

well, a stock m54b30 with 10.2:1 comp. ratio is rated at 231hp. I'm waiting somwhere 260hp maybe more with good cams and stock management. I will use 98 octane fuel only, and yes cometic MLS 0.070 headgasket will be safe.

[10Toes]

Cool build, I'm building a m50 2.8 11.25:1 compression.

Starting with a m50tu
M50b25 piston
135 rods
M52b28 crank 84mm forged

I still need to find a set of cams problem use us spec s50 or s52

[Wh33lhop]

I'm building M50 3.0 liter storker for my E30.
Have a lot of work done choosing differrent piston and rod combo and finally here's it is:
M54B30 crankshaft
135mm rods
M42B18 84mm pistons
Iron M50B25 block

I'm getting:
89.6mm stroke divide by 2 + 135mm rod + M42 piston 31.65 compression height and I'm 0.45mm over deck and with stock 1.7mm headgasket and piston dish somwhere 5-7cc getting 12.0-11.6:1 compression ratio. al this will be managed by siemens MS40.0. Why? Because I have non Vanos head but really need knock sensors with such a high compression, so the MS40.0 is the only non-vanos management with knock sensors.

I'd like to listen for wise engine builders, maybe I'm mistaken in something?

Nice, what will you be using for cams? M3 cams are good all-rounders, but with such a high SCR you may want to go a little more aggressive to lower the dynamic CR. 12:1 is pretty nuts. Do us a favor and document the results, yeah?

[Leo_328i]

Cool build, I'm building a m50 2.8 11.25:1 compression.

Starting with a m50tu
M50b25 piston
135 rods
M52b28 crank 84mm forged

I still need to find a set of cams problem use us spec s50 or s52

This is a little off-topic but I've kept reading that the M50 B25 pistons on a M52 B28 motor = 11.25 compression but I haven't seen anyone do the math behind it to confirm that compression is that high!

Another source I saw with that build said that the compression would be raied from 10.2 to 10.6.

[blink977]

Cool build, I'm building a m50 2.8 11.25:1 compression.

Starting with a m50tu
M50b25 piston
135 rods
M52b28 crank 84mm forged

I still need to find a set of cams problem use us spec s50 or s52

I dont want to go with vanos head cause non vanos valvetrain is much better for high revs. non vanos has 7mm valve steams and double valve springs vs vanos 6mm valve steam and single spring.
As for your build: You meant M50B25TU or M52B25 piston cause with M50B25 non vanos piston you are 4.2mm above the deck! with vanos piston you are 1.3mm below the deck and with stock 0.070 headgasket you will have 10.1:1 comp. ratio. with 0.030 headgasket - 11.2:1 comp. so you are correct in youre mathematics :D

[blink977]

Nice, what will you be using for cams? M3 cams are good all-rounders, but with such a high SCR you may want to go a little more aggressive to lower the dynamic CR. 12:1 is pretty nuts. Do us a favor and document the results, yeah?

as i will complete my build i will post results. maybe i will use S50 cams or move my intake cam to exhaust and buy a shrick cam, I don't know yet. I'm also thinking about head porting, such a high comp. needs better air flow then stock.

[F34R]

Cool build, I'm building a m50 2.8 11.25:1 compression.

Starting with a m50tu
M50b25 piston
135 rods
M52b28 crank 84mm forged

I still need to find a set of cams problem use us spec s50 or s52

I have been told the s52 cams are hotter but they both show about the same performance. I know the s52 cams have a broad band of trq through out. You will need the m52/s52 cam trays to use the s52 cams BTW.

[Bmwmotorm52]

Not trying to kill your thread,but i lookin for info on a m50b28(nv) build. looking for sumthing i can run on my stock ECU with a tune.

[FreedS4]

Any updates on your build OP? Thanks

Chris