Alpina 3.3 litre 300 Bhp engine
Discussion
I have some technical questions about the Alpina based M50/M5X engine- if anyone could help or has any links I would be greatful:
1) WHat is the bore and stroke
2) Does it still use the Alloy block or has it gone back to the cast iron block of earlier M50s/US S50s?
3) What does this engine rev to?
The questions are for a upstream ressearch for my E21 engine project.
I'm pretty set on a 2 valve "M20" motor stretched out to 3.1 litres but to keep an open mind- the other option would be to reduce weight of the cast iron block (really heavy) S50 euro M3 engine I have for this is too heavy and even heavier then the old 3.5 litre "M30" unit.
I have a theory that the ally block of the 231 Bhp 330i engine will be marginal if bored out.
My reasons for thinking this are the following:
-BMW offer only one small increment of oversize pistons for this engine unlike their cast iron units.
-Whenever BMW have gone for a bore size bigger then 84mm on either their US M3s or Euros they have always used a cast iron block
-BMW probably would have gone oversquare with this design if they could have ( as this would help port/valve flow by de-shrouding the valves) as they seem suitably obsessed with wide Open Throttle performance in most of their engineering priorities!
I've seen the standard 330i engine stripped out and it does have what looks like little reinforcement brackets that bridge the main bearing caps to the block skirt. But these could be there for any number of reasons.
This is why information on the Alpina engine would be helpful.
>>> Edited by Marquis_Rex on Thursday 13th January 19:18
1) WHat is the bore and stroke
2) Does it still use the Alloy block or has it gone back to the cast iron block of earlier M50s/US S50s?
3) What does this engine rev to?
The questions are for a upstream ressearch for my E21 engine project.
I'm pretty set on a 2 valve "M20" motor stretched out to 3.1 litres but to keep an open mind- the other option would be to reduce weight of the cast iron block (really heavy) S50 euro M3 engine I have for this is too heavy and even heavier then the old 3.5 litre "M30" unit.
I have a theory that the ally block of the 231 Bhp 330i engine will be marginal if bored out.
My reasons for thinking this are the following:
-BMW offer only one small increment of oversize pistons for this engine unlike their cast iron units.
-Whenever BMW have gone for a bore size bigger then 84mm on either their US M3s or Euros they have always used a cast iron block
-BMW probably would have gone oversquare with this design if they could have ( as this would help port/valve flow by de-shrouding the valves) as they seem suitably obsessed with wide Open Throttle performance in most of their engineering priorities!
I've seen the standard 330i engine stripped out and it does have what looks like little reinforcement brackets that bridge the main bearing caps to the block skirt. But these could be there for any number of reasons.
This is why information on the Alpina engine would be helpful.
>>> Edited by Marquis_Rex on Thursday 13th January 19:18
Ok, I tracked this info down on the latest 3.4 litre Alpina - it was nested and hiding somewhere within their official website:
Cylinder in-line 6
Capacity cm³ 3346
Bore mm 87.0
Stroke mm 93.8
Compresson ratio :1 10.2
Max. power kW/bhp 221/300
at rpm 6300
Max. torque Nm 362
at rpm 4800
Engine management Siemens DME MS 43
Fuel 98 RON
Emission classification Euro 3
They've managed to take out the venerable six pot to an 87mm bore and that's with 91 mm bore centres which only leaves 4 mm cylinder Bridge distance!
This engine has GOT to be cast iron surely.
So now all I need to know for sure is whether it is cast iron or an alloy block.
Cylinder in-line 6
Capacity cm³ 3346
Bore mm 87.0
Stroke mm 93.8
Compresson ratio :1 10.2
Max. power kW/bhp 221/300
at rpm 6300
Max. torque Nm 362
at rpm 4800
Engine management Siemens DME MS 43
Fuel 98 RON
Emission classification Euro 3
They've managed to take out the venerable six pot to an 87mm bore and that's with 91 mm bore centres which only leaves 4 mm cylinder Bridge distance!
This engine has GOT to be cast iron surely.
So now all I need to know for sure is whether it is cast iron or an alloy block.
xm5er said:
From the various reviews I've read of the Z4alpina which uses the unit, I'm almost certain it is a revision of the old cast iron 3.0l M3 block.
Why not go for an M3evo unit, Vanos issues can be managed apparently by changing the vanos oil filter with each oil change.
VANOS issues don't scare me, you have to ensure you use the longer Vanos bolts and make sure they're locktited in- along with the vanos filter changes.
I wasn't thinking of using the Alpina engine.
The problem with the M3 engine is that it is collosally heavy. I have an S50 sitting under covers in my back yard. It is one of my favourite engines- but it weighs about 220 Kgs. This is heavier then the "big M30 six" 3.5 litre and will make my E21 handle like a TWR Alpina 335i-
This compares very unfavourably with my current M20s 175 Kgs.
The BMW 330i/328i M50/M52 alloy block motors weighs about 160-170 kgs so are incredibly light. I had thought about trying to retro fit the alloy block from the M50/M52 and use a tailor made head gasket to get the required extra 10mm deck height, but as hinted in the original thread, if you bore out the alloy block I think it could prove detrimental to cylinder block rigidity.
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