Alpina 3.3 litre M50 based 300 Bhp engine question
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.
[posted again from the BMW forum to get maximum coverage!]
>>> Edited by Marquis_Rex on Thursday 13th January 19:22
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.
[posted again from the BMW forum to get maximum coverage!]
>>> Edited by Marquis_Rex on Thursday 13th January 19:22
nel were I to go this route (which at this stage seems unlikely- but I'm still investigating) I would probably iron liner the engine.
I have seen alloy engines with as little as only 4mm between bores- such as the M5 V8 and a few others- however it is probably stronger to bore out an engine with alusil then one fitted with liners.
Also- it may not be the wall thickness that is the issue- but something else- bore distorsion or some kind of fatigue.
I have seen alloy engines with as little as only 4mm between bores- such as the M5 V8 and a few others- however it is probably stronger to bore out an engine with alusil then one fitted with liners.
Also- it may not be the wall thickness that is the issue- but something else- bore distorsion or some kind of fatigue.
Colleague at work on my last project had a strange engine failure on his V8 engined 5 series BMW. One morning, out of the blue, it just turned over like sewing machine, no compression. BMW replaced the engine without saying a word - apparently a problem with the nikasil bore hardening. I suspect they've had a few...
Anyway, this isn't getting you any further on your quest for info - good luck!
Anyway, this isn't getting you any further on your quest for info - good luck!
Yeah Nel, Nickasil is bad news on some BMW engines- worse with high sulphur fuels and with alot of cold start motoring on engines with huge coolant capacities- as suphuric acid forms on the bores and abrasively attacks the coating.
It's good for me- because I can go to my BMW parts contact and get knackered engines DEAD cheap and get them relinered-ready for tinkering!
The M5 uses Alusil which doesn't suffer from this.
It's good for me- because I can go to my BMW parts contact and get knackered engines DEAD cheap and get them relinered-ready for tinkering!
The M5 uses Alusil which doesn't suffer from this.
I have what you are looking for, but:
I'm not quite sure it's right to start to release this data to just anyone, so I must be discriminate as to what should be disclosed.
Sorry, I just could not restrain myself from this pun.
I do not have any information that would help you.
If I did, I would give it to you.
Cheers Peter
I'm not quite sure it's right to start to release this data to just anyone, so I must be discriminate as to what should be disclosed.
Sorry, I just could not restrain myself from this pun.
I do not have any information that would help you.
If I did, I would give it to you.
Cheers Peter
the problem with reducing the thickness of the walls maybe the head gasket. if you go to thin (and you can get one for the bore you want) it maybe very weak and not take even stock output! this is a problem on small block chevis in the states. there are BIG bore blocks, but you are limited to the amout of power you can run by the head gasket!
if my memory is right i think Alpina stroke the engines. but im not possitive.
thanks CHris.
if my memory is right i think Alpina stroke the engines. but im not possitive.
thanks CHris.
Hi Chris, I've duplicated this thread on the BMW forum, and I've found out that BMW have bored and stroked the engine.
They've used an 87mm bore with a 91mm bore centre giving them only a 4mm bridge distance. I've always said it was possible with people who KNOW what they're doing and HOW to engineer( STILL we have to endure the crap that BMW engineering is over rated and the Rover K series is the best engine in the world!). To get around the potential head gasket issues I can only hypothesise that using a tri-metal layer gasket alleviates this.
It SHARES this in common with the E46 M3. I think both blocks are cast iron though. I need to find out if the Alpina engine is cast iron or alloy now.
The only alloy engine I've seen with a distance o 4 mm between bores is the outgoing BMW M5 V8 and a V6 prototype.
They've used an 87mm bore with a 91mm bore centre giving them only a 4mm bridge distance. I've always said it was possible with people who KNOW what they're doing and HOW to engineer( STILL we have to endure the crap that BMW engineering is over rated and the Rover K series is the best engine in the world!). To get around the potential head gasket issues I can only hypothesise that using a tri-metal layer gasket alleviates this.
It SHARES this in common with the E46 M3. I think both blocks are cast iron though. I need to find out if the Alpina engine is cast iron or alloy now.
The only alloy engine I've seen with a distance o 4 mm between bores is the outgoing BMW M5 V8 and a V6 prototype.
Hi
I got some information to your questions from here:
www.auto-treff.com/bmw/vb/forumdisplay.php?s=eb009de2c31e8faa140857dbdd686083&forumid=62
According to some Alpina owners and enthusiasts, the 3.3 engines from Alpina are all cast iron.
The bore / stroke is 86,4 / 93,8 mm
Absolute rev. limit according to the user (before rev. limiter) is 7200 rpm.
The Alpina manual mentioned 6400 rpm.
Furthermore, all engines come in 280 HP / 206kW and 335 Nm @ 4500 rpm.
Cheers Peter
I got some information to your questions from here:
www.auto-treff.com/bmw/vb/forumdisplay.php?s=eb009de2c31e8faa140857dbdd686083&forumid=62
According to some Alpina owners and enthusiasts, the 3.3 engines from Alpina are all cast iron.
The bore / stroke is 86,4 / 93,8 mm
Absolute rev. limit according to the user (before rev. limiter) is 7200 rpm.
The Alpina manual mentioned 6400 rpm.
Furthermore, all engines come in 280 HP / 206kW and 335 Nm @ 4500 rpm.
Cheers Peter
Thanks alot Peter, you evidently speak fluent German!
That would support the theory that the alloy block at that bore diameter may not be robust. Not the answer I wanted to hear
It's a shame- because the S50 M3 engine is 45 kgs more then my SOHC M20 2 valver- which is unacceptable for handling. I can't move the engine any further back in the bay unless I remove the heater matrix.
That would support the theory that the alloy block at that bore diameter may not be robust. Not the answer I wanted to hear
It's a shame- because the S50 M3 engine is 45 kgs more then my SOHC M20 2 valver- which is unacceptable for handling. I can't move the engine any further back in the bay unless I remove the heater matrix.
how about junking some "unwanted" stuff from the engine bay? i read about someone racing a BMW M3 that managed to reduce the weight by 60Kg from under the bonnet alown! lets say you could only get away with half that, thats still 30kg. dont know how far you want to go but you could move things to the boot. battery and some tanks are an easy enough to do and pretty comon. moving the weight further back will then allow you to use the iron block.
also, have you looked into forced induction? i have heard that these engines (i think the iron blocks) will take a loads of boost standard! even the alloy block should beable to handle 5-7psi of boost from a intercooled supercharger. this way you would get the power you want with less weight than the iron block.
thanks Chris.
also, have you looked into forced induction? i have heard that these engines (i think the iron blocks) will take a loads of boost standard! even the alloy block should beable to handle 5-7psi of boost from a intercooled supercharger. this way you would get the power you want with less weight than the iron block.
thanks Chris.
I'm looking into the reduction of anciliary mass.
The flywheel on the M3 weighs 11 Kg and that can be reduced to 3-4 Kgs, while idle speed control can go straight to the dump. I don't know if the quoted weight (220 Kgs vs M20 175 Kgs) includes Air con-probably not.
Battery can be moved to the boot.
This engine WILL NOT be boosted. Not interested.
My 993TT has made me realise that- don't like the noise boosted engines make. To most people here it's just about getting the power and torque full stop. Not to me, I'm a purist and prefer a revvy naturally aspirated "sweet" engine that "sings"- but I realise that will be lost on many.
The flywheel on the M3 weighs 11 Kg and that can be reduced to 3-4 Kgs, while idle speed control can go straight to the dump. I don't know if the quoted weight (220 Kgs vs M20 175 Kgs) includes Air con-probably not.
Battery can be moved to the boot.
This engine WILL NOT be boosted. Not interested.
My 993TT has made me realise that- don't like the noise boosted engines make. To most people here it's just about getting the power and torque full stop. Not to me, I'm a purist and prefer a revvy naturally aspirated "sweet" engine that "sings"- but I realise that will be lost on many.
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