Why No 3.5 Liter?

ENINTY · 11-14-2010, 05:58 AM

So I got to thinking last night, why no larger in-line 6 than 3 liters for the E90? With even with Ford now producing a world-class 300 HP 3.7 liter V6 why can't BMW bag the obviously to-hard-to-make-reliable twin-turbo N54 (or turbo N55) 3 liter and just up the engine size for a 300 HP natural induction straight 6? They used to make them that way. The Mustang gets better gas mileage than the 335i so I see no case for a fuel mileage argument.

J02 335i · 11-14-2010, 06:13 AM

Take the S54 for example, 333hp 262tq (I think) all in a 3.2L makes this a very expensive engine to produce, where as the N54 is a very common platform for BMW and probably very cheap for them to tune down compression and slap on a couple (or single N55) turbo(s) to make a huge power increase. With reasonable fuel economy.

All in all I think this (N54,N55) was a lot cheaper for BMW to produce then build a completely new engine. I think its all about the $.

ENINTY · 11-14-2010, 06:32 AM

Quote:

Originally Posted by J02 335i

Take the S54 for example, 333hp 262tq (I think) all in a 3.2L makes this a very expensive engine to produce, where as the N54 is a very common platform for BMW and probably very cheap for them to tune down compression and slap on a couple (or single N55) turbo(s) to make a huge power increase. With reasonable fuel economy.

All in all I think this (N54,N55) was a lot cheaper for BMW to produce then build a completely new engine. I think its all about the $.

Maybe, but the N54 is a completely different engine than the N52, so when deciding to build the 300HP N54 BMW could have just as easily built a larger N52-based 3.5 or 3.7 liter naturally aspirated 300HP engine. It doesn't take much to bump the stroke and add a few MM's in bore size to gain displacement. Seems a lot cheaper to do that than create a twin turbo 3.0L that they obviously have lots of engineering issues with.

John 070 · 11-14-2010, 06:39 AM

Turbocharging seems to be the way every car co. is going, with smaller displacement. The new Chevy Cruze is 1.4L and has excellent fuel economy and torque.

BMW messed up with the N54, but it doesn't mean that every car co. has. Direct injection and turbocharging was the right direction on paper, others are doing it, and perfectly fine.

markinva · 11-14-2010, 09:26 AM

Ford's "state of the art" 300 hp 3.7 V6 doesn't hold a candle to the N54 in terms of performance and driving experience.

280 lb/ft of tq @ 4250 rpm for the Ford vs 300 lb/ft (+) @ 1400 rpm for the n54.

Around town, these feel like completely different engines.

J02 335i · 11-14-2010, 09:32 AM

Quote:

Originally Posted by markinva

Ford's "state of the art" 300 hp 3.7 V6 doesn't hold a candle to the N54 in terms of performance and driving experience.

280 lb/ft of tq @ 4250 rpm for the Ford vs 300 lb/ft ( ) @ 1400 rpm for the n54.

Around town, these feel like completely different engines.

This is a very good point.

hipnotic · 11-14-2010, 09:39 AM

+1

HoustonScott · 11-14-2010, 09:48 AM

Deep in the bowels of BMW they know the N54 and N55 engines are problematic and have been an embarrassment and failure. High engine oil temps, turbo failures, HPFP problems, on and on....They know this and deep inside BMW I bet a new engine is on the drawing boards. The N55 was a quick fix to give more time to a new engine. The capability to expand to 3.5L will certainly be a part of that new engine.

HS

Wires · 11-14-2010, 09:52 AM

Quote:

Originally Posted by markinva

Ford's "state of the art" 300 hp 3.7 V6 doesn't hold a candle to the N54 in terms of performance and driving experience.

280 lb/ft of tq @ 4250 rpm for the Ford vs 300 lb/ft (+) @ 1400 rpm for the n54.

Around town, these feel like completely different engines.

+1

Funny thing about posted HP numbers is NOBODY ever posts the dyno curves for them. Dodge is notorious for posting their huge HP #'s. Problem is powerband sucks. Sure PEAK HP is great, but means nothing unless you're at the track with the revs there all the time. Nice flat torque band is what you want.

timmahh · 11-14-2010, 10:23 AM

Is it something to do with CAFE standards? They've got quite a few bigger motors, they need some smaller ones to keep mileage good, adding a turbo [or two] bumps power to make it perform like a bigger [displacement] engine.

Question here BTW, doesn't the xx5 reference the turbo on the new models?

335 = 3.0 Liter + Turbos
550 = 4.4 Liter + Turbos

The turbo setup more or less takes the place of another half liter of engine displacement.. yay or nay?

Saintor · 11-14-2010, 10:48 AM

Quote:

Originally Posted by ENINTY

So I got to thinking last night, why no larger in-line 6 than 3 liters for the E90? With even with Ford now producing a world-class 300 HP 3.7 liter V6 why can't BMW bag the obviously to-hard-to-make-reliable twin-turbo N54 (or turbo N55) 3 liter and just up the engine size for a 300 HP natural induction straight 6? They used to make them that way. The Mustang gets better gas mileage than the 335i so I see no case for a fuel mileage argument.

Excellent question. And the 22K$ Mustang 3.7 clocks a 0-60mph in the low 5s like the 335i (BMW reports 5.4s manual), get better mpg and runs on regular.

Also there are non turbo engines with their peak torque at low rpm. For example, the N53 found in the Euro 523i has its peak torque from 1500-4250rpm.

I absolutely agree with you. There is no reason to have a TWIN-TURBO (now single) engine with this nonsense complexity & cost for only 300HP unless you intent to tune it. I'd prefer a larger 3.5L non turbo as well.

Coolieman1220 · 11-14-2010, 10:53 AM

BMW had a 3.5 straight six in the old M535i and the M6 and M1. I believe it was an S model engine. keep in mind a 3.5l straight six will be a bit larger to fit in. They could do it...however i think turbo's are gonna be the way to go....

Drivaar · 11-14-2010, 10:54 AM

I've read that BMW claims it's hard to get more than 0.5 liters of displacement per cylinder in the inline-6 configuration (even though they have done 3.5L inline-6 engines in some older models.).

(Seems like an odd claim to me, but there must be something to it.)

Also, the N54 (and N55) to deliver a lot... plenty of torque everywhere, nice HP, and great highway MPGs. That said, you need to compare direct injection vs. direct injection to be fair. The N54/55 use it, so they get much better mileage than competitors who don't.

The point is to compare the N54/55 to a direct-injection 3.5L 330 HP motor. Is there one out there?

SCMike · 11-14-2010, 12:46 PM

Quote:

Originally Posted by Drivaar

I've read that BMW claims it's hard to get more than 0.5 liters of displacement per cylinder in the inline-6 configuration (even though they have done 3.5L inline-6 engines in some older models.).

(Seems like an odd claim to me, but there must be something to it.)

Seems odd to me also. Sitting out in my garage is an XKE with a 4.2 liter 6-cylinder engine - it's ancient. Also, in excess of 5 million Jeeps have been built with the 4 liter 6-cylinder. Maybe it's something about current emissions standards, but I would have thought a good engineer could have designed a modern cylinder head to meet them. Just like a good engineer could have designed a direct injection, twin-turbo system that does not fail big time - oops.

mundo74 · 11-14-2010, 12:56 PM

Got to admit it. Although I am partial to turbos this whole downsizing and turbos thing as car and driver states does not add up. They compared similar engines from the same manufacturer that produced similar power and found the turbo models consumed more fuel in everyday driving it's slightly larger counterpart

Blubaron79 · 11-14-2010, 01:42 PM

A turbo engine always has a better torque curve, and better delivery of power.

3.5 6 would be garbage.

galahad05 · 11-14-2010, 01:56 PM

If you're talking inline six cylinder engines, increasing displacement is a packaging issue.

The engine gets looooong. This increases weight, and in a bad place--the front of the car.

bimmer_335 · 11-14-2010, 03:17 PM

I'm sure Mustang's engine weighs more then N54 or N55. Thats one of the advantages of adding turbos, you get max power without the burden of extra lbs... which is very important for a bimmer.

Saintor · 11-14-2010, 03:23 PM

People would be surprised that turbo engines are not that lightweight with all those supporting systems. For example, a Ford V6 3.5 Ecoboost weights more than a Ford V8 5.0 Coyote.

jayback42 · 11-14-2010, 03:30 PM

I think that the turbos are what make the 335i a unique and special car. Bump up the displacement and ditch the turbos and it looses its cool imo. However, improvements in reliability would be nice.

bonsai · 11-14-2010, 04:53 PM

Given the tune-ability of the N54, I'm totally fine with the current setup. Now, a 3.5L twin turbo would have been awesome-sauce on top of turbo tune-spaghetti.

TheRox · 11-14-2010, 05:12 PM

Quote:

Originally Posted by Blubaron79

A turbo engine always has a better torque curve, and better delivery of power.

3.5 6 would be garbage.

Umm...torque curve maybe...but power deliverY? last I checked turbo engined, including ours are laggy...and not as responsive as light 6 cyl NA ones.

Porsche's V6 from the Panamera makes 300 hp/300 TORQUE...3.6 L displacement...revs high, naturally aspirated...pure driving experience type of engine. Better fuel economy than BMW.

Then again, its Porsche. BMW is a little outclassed.

HOWEVER, given that most people daily drive their x35 cars..and many are auto, it makes sense to turbocharge them. You don't need a motorsport responsive naturally aspirted engine for daily driving. I prefer one, but most people do not.

11-14-2010, 05:58 AM	#1
ENINTY Banned 173 Rep 3,415 Posts Drives: 2006 325i Sport Join Date: Jun 2006 Location: Virginia iTrader: (0)	Why No 3.5 Liter? So I got to thinking last night, why no larger in-line 6 than 3 liters for the E90? With even with Ford now producing a world-class 300 HP 3.7 liter V6 why can't BMW bag the obviously to-hard-to-make-reliable twin-turbo N54 (or turbo N55) 3 liter and just up the engine size for a 300 HP natural induction straight 6? They used to make them that way. The Mustang gets better gas mileage than the 335i so I see no case for a fuel mileage argument.
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11-14-2010, 06:13 AM	#2
J02 335i Lieutenant Colonel 39 Rep 1,558 Posts Drives: F80 M3 Join Date: Aug 2010 Location: Ontario iTrader: (1)	Take the S54 for example, 333hp 262tq (I think) all in a 3.2L makes this a very expensive engine to produce, where as the N54 is a very common platform for BMW and probably very cheap for them to tune down compression and slap on a couple (or single N55) turbo(s) to make a huge power increase. With reasonable fuel economy. All in all I think this (N54,N55) was a lot cheaper for BMW to produce then build a completely new engine. I think its all about the $. __________________ Sport pack, JB3, Dci, factory oil cooler, 18" M3 reps, Michelin PSS, painted trim, black grills, smoked side markers, LED plate lights, H&R coils, Borla catback
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11-14-2010, 06:39 AM	#4
John 070 Lieutenant General 1707 Rep 14,829 Posts Drives: 335i cpe Join Date: Oct 2006 Location: ZSP/ZPP/ZCW iTrader: (0)	Turbocharging seems to be the way every car co. is going, with smaller displacement. The new Chevy Cruze is 1.4L and has excellent fuel economy and torque. BMW messed up with the N54, but it doesn't mean that every car co. has. Direct injection and turbocharging was the right direction on paper, others are doing it, and perfectly fine.
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11-14-2010, 09:26 AM	#5
markinva Lieutenant 20 Rep 402 Posts Drives: 2021 M4 G82 Join Date: Nov 2008 Location: NOVA iTrader: (0)	Ford's "state of the art" 300 hp 3.7 V6 doesn't hold a candle to the N54 in terms of performance and driving experience. 280 lb/ft of tq @ 4250 rpm for the Ford vs 300 lb/ft (+) @ 1400 rpm for the n54. Around town, these feel like completely different engines.
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11-14-2010, 09:39 AM	#7
hipnotic Major General 149 Rep 6,604 Posts Drives: e92 335i Join Date: Oct 2007 Location: So. Cal iTrader: (7) Garage List 2008 335i coupe [7.00]	+1
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11-14-2010, 09:48 AM	#8
HoustonScott Lieutenant 21 Rep 436 Posts Drives: 2010 335d, montego Blue Join Date: Nov 2009 Location: Houston, Tx iTrader: (0)	Deep in the bowels of BMW they know the N54 and N55 engines are problematic and have been an embarrassment and failure. High engine oil temps, turbo failures, HPFP problems, on and on....They know this and deep inside BMW I bet a new engine is on the drawing boards. The N55 was a quick fix to give more time to a new engine. The capability to expand to 3.5L will certainly be a part of that new engine. HS
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11-14-2010, 10:23 AM	#10
timmahh ghey 484 Rep 2,041 Posts Drives: Viertürigen Fahrzeugs Join Date: Oct 2010 Location: Southern California iTrader: (1)	Is it something to do with CAFE standards? They've got quite a few bigger motors, they need some smaller ones to keep mileage good, adding a turbo [or two] bumps power to make it perform like a bigger [displacement] engine. Question here BTW, doesn't the xx5 reference the turbo on the new models? 335 = 3.0 Liter + Turbos 550 = 4.4 Liter + Turbos The turbo setup more or less takes the place of another half liter of engine displacement.. yay or nay? __________________ 21 G05 > 20 G05 > 17 G30 > 14 F30 > 08 E90
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11-14-2010, 10:53 AM	#12
Coolieman1220 Banned 73 Rep 1,770 Posts Drives: 2010 335d Join Date: Jul 2010 Location: New York City iTrader: (0)	BMW had a 3.5 straight six in the old M535i and the M6 and M1. I believe it was an S model engine. keep in mind a 3.5l straight six will be a bit larger to fit in. They could do it...however i think turbo's are gonna be the way to go....
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11-14-2010, 10:54 AM	#13
Drivaar Lieutenant 73 Rep 463 Posts Drives: BMW Join Date: Aug 2010 Location: Earth iTrader: (0)	I've read that BMW claims it's hard to get more than 0.5 liters of displacement per cylinder in the inline-6 configuration (even though they have done 3.5L inline-6 engines in some older models.). (Seems like an odd claim to me, but there must be something to it.) Also, the N54 (and N55) to deliver a lot... plenty of torque everywhere, nice HP, and great highway MPGs. That said, you need to compare direct injection vs. direct injection to be fair. The N54/55 use it, so they get much better mileage than competitors who don't. The point is to compare the N54/55 to a direct-injection 3.5L 330 HP motor. Is there one out there?
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11-14-2010, 12:56 PM	#15
mundo74 Lieutenant 67 Rep 563 Posts Drives: F10M5 Join Date: Oct 2005 Location: P.Pines, FL iTrader: (2)	Got to admit it. Although I am partial to turbos this whole downsizing and turbos thing as car and driver states does not add up. They compared similar engines from the same manufacturer that produced similar power and found the turbo models consumed more fuel in everyday driving it's slightly larger counterpart
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11-14-2010, 01:42 PM	#16
Blubaron79 Brigadier General 1435 Rep 4,724 Posts Drives: 2021 M340i xDrive Join Date: May 2009 Location: PA iTrader: (0)	A turbo engine always has a better torque curve, and better delivery of power. 3.5 6 would be garbage. __________________ Current: 2021 M340i xDrive Previous: '18 340i xDrive; '15 335 xDrive; '14 435i xDrive; '09 335 E92 xDrive
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11-14-2010, 01:56 PM	#17
galahad05 Brigadier General 158 Rep 3,158 Posts Drives: '07 335i e90 Join Date: Mar 2008 Location: Long Island NY iTrader: (0)	If you're talking inline six cylinder engines, increasing displacement is a packaging issue. The engine gets looooong. This increases weight, and in a bad place--the front of the car. __________________ Always do right. This will gratify some people and astonish the rest. --Mark Twain
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11-14-2010, 03:17 PM	#18
bimmer_335 Major 177 Rep 1,123 Posts Drives: 540 mSport Join Date: Jul 2009 Location: In the middle of nowhere, TX iTrader: (1)	I'm sure Mustang's engine weighs more then N54 or N55. Thats one of the advantages of adding turbos, you get max power without the burden of extra lbs... which is very important for a bimmer.
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11-14-2010, 03:23 PM	#19
Saintor Banned 82 Rep 2,446 Posts Drives: E90 Join Date: Sep 2005 Location: MTL, Canada iTrader: (1)	People would be surprised that turbo engines are not that lightweight with all those supporting systems. For example, a Ford V6 3.5 Ecoboost weights more than a Ford V8 5.0 Coyote.
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11-14-2010, 03:30 PM	#20
jayback42 Private 2 Rep 79 Posts Drives: 2008 e90 335i Join Date: Nov 2010 Location: Costa Mesa, CA iTrader: (0)	I think that the turbos are what make the 335i a unique and special car. Bump up the displacement and ditch the turbos and it looses its cool imo. However, improvements in reliability would be nice.
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11-14-2010, 04:53 PM	#21
bonsai OG 3er 84 Rep 295 Posts Drives: 2016 F80 M3/2018 F82 M4 Compet Join Date: Sep 2007 Location: San Francisco, CA. iTrader: (0)	Given the tune-ability of the N54, I'm totally fine with the current setup. Now, a 3.5L twin turbo would have been awesome-sauce on top of turbo tune-spaghetti.
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