BMW (Toyota Supra) B58 Engine Teardown Video

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Originally Posted by MCompact
As I've said many times before, if your idea of the pinnacle of automotive excellence is an anodyne travel pod that can go 300k miles with minimal maintenance, than a BMW is not for you. As for me, the enjoyment I've derived from the BMWs I've owned since 1983 vastly outweigh the additional expense of maintaining them.



As much as I dislike driving BMWs after being a porter for them, I must say, the M235i is pretty fun to drive. I'm just glad it's my friend's car and not mine lol.
 
Originally Posted by atikovi
Originally Posted by edyvw
I am not big fan of chain in the back. So far it proved stout in since 2016.

That's probably what they said of Audi's S4.

The difference between the two designs is staggering; the only thing they have in common is where the chain is physically located.
Originally Posted by madRiver
Originally Posted by Bjornviken
looks like a solid engine

Looked not looks.....

No, looks. It looks like a beast of a motor that will handle big power - as he said in the video.
Originally Posted by madRiver
These clowns just reduced the car to about 30k with problems once they put that back in.

"Clowns" Not the word I'd use to describe the builder in the video. It's a word that suits several of the posters here though.
 
Originally Posted by andyd
School me please. What, pray tell, is the rationale behind a rear timing chain/belt? In the factory, the cabins are dropped onto the drive train The right way to take out an engine is on the sub-frame from underneath and then split off the engine or trans to service. KA- Ching!! and difficult to bodge behind the shop. The main reason I don't have a late model Ranger 4x4 is a rear cam drive 4.0L Take a good reliable little gas hog capable of 300K with little service and turn it into a grenade at 150K miles . A century of development going into push rod V engines. Then these OHC horror shows. What is the impetus to do this for Ford or BMW or any car maker?
coffee2.gif



Chain on back of engine, or toward the center of the car, is for weight distribution. Keeping that extra weight off the front/nose of the car has handling advantages. Of course that means you have to pull the engine for timing chain service...
 
Originally Posted by Deontologist
Originally Posted by andyd
School me please. What, pray tell, is the rationale behind a rear timing chain/belt? In the factory, the cabins are dropped onto the drive train The right way to take out an engine is on the sub-frame from underneath and then split off the engine or trans to service. KA- Ching!! and difficult to bodge behind the shop. The main reason I don't have a late model Ranger 4x4 is a rear cam drive 4.0L Take a good reliable little gas hog capable of 300K with little service and turn it into a grenade at 150K miles . A century of development going into push rod V engines. Then these OHC horror shows. What is the impetus to do this for Ford or BMW or any car maker?
coffee2.gif



Chain on back of engine, or toward the center of the car, is for weight distribution. Keeping that extra weight off the front/nose of the car has handling advantages. Of course that means you have to pull the engine for timing chain service...

Not necessarily. BMW was able to achieve perfect distribution with older engines. 335i with N55 engine had distribution 49/51% in F30 model. I think return of good ole mechanical pump and some other design changes made timing chain in the back more efficient.
Also, according to some people on bimmerfest and other forums engine does not have to come out to change chain if special tools are available. How? I have no idea.
 
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Originally Posted by edyvw
Not necessarily. BMW was able to achieve perfect distribution with older engines. 335i with N55 engine had distribution 49/51% in F30 model.


I can build a car with 2000 pounds in front of the front axle and 2000 pounds behind the rear axle and get a "perfect" 50/50 weight distribution.

But would you track such a car? Or would you prefer that the weight be more concentrated toward the center of the vehicle?

BMW's obsession with "weight distribution" is little more than marketing. It's not really about 50/50 front/rear. More important is where the weight is located.
 
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Originally Posted by Deontologist
Originally Posted by andyd
School me please. What, pray tell, is the rationale behind a rear timing chain/belt? In the factory, the cabins are dropped onto the drive train The right way to take out an engine is on the sub-frame from underneath and then split off the engine or trans to service. KA- Ching!! and difficult to bodge behind the shop. The main reason I don't have a late model Ranger 4x4 is a rear cam drive 4.0L Take a good reliable little gas hog capable of 300K with little service and turn it into a grenade at 150K miles . A century of development going into push rod V engines. Then these OHC horror shows. What is the impetus to do this for Ford or BMW or any car maker?
coffee2.gif



Chain on back of engine, or toward the center of the car, is for weight distribution. Keeping that extra weight off the front/nose of the car has handling advantages. Of course that means you have to pull the engine for timing chain service...


Huh? No, that is not true. It is because it is a modular engine, can be a 3,4 or 6 cylinder, transverse or longitudinal. Has nothing to do with balance. And you do not have to remove the engine, or tranny, to replace the chain. Unlike Audi, BMW can actually design an engine. Ha ha!

Fun fact, the B48 and B58 are the last new gas engines BMW has designed. No more gas engines are being designed now. It will be these engines until we go full electric only.
 
Originally Posted by Deontologist
Originally Posted by edyvw
Not necessarily. BMW was able to achieve perfect distribution with older engines. 335i with N55 engine had distribution 49/51% in F30 model.


I can build a car with 2000 pounds in front of the front axle and 2000 pounds behind the rear axle and get a "perfect" 50/50 weight distribution.

But would you track such a car? Or would you prefer that the weight be more concentrated toward the center of the vehicle?

BMW's obsession with "weight distribution" is little more than marketing. It's not really about 50/50 front/rear. More important is where the weight is located.

BMW engine sits behind front wheels. I know what you referring to, but not sure how you came to the conclusion that BMW engine does not sit behind wheels or that weight is not between axles.
 
Originally Posted by edyvw
Originally Posted by Deontologist
I can build a car with 2000 pounds in front of the front axle and 2000 pounds behind the rear axle and get a "perfect" 50/50 weight distribution.

But would you track such a car? Or would you prefer that the weight be more concentrated toward the center of the vehicle?

BMW's obsession with "weight distribution" is little more than marketing. It's not really about 50/50 front/rear. More important is where the weight is located.

BMW engine sits behind front wheels. I know what you referring to, but not sure how you came to the conclusion that BMW engine does not sit behind wheels or that weight is not between axles.


I came to that conclusion in my post? Nothing in my post says anything to that effect. I never said anything about where a BMW engine is located with regard to the axles or wheels. The point is that "50/50" can be achieved through many ways, some less optimal than others. In effect, claiming a "50/50" "weight distribution" is so vague as to be useless. A Toyota Camry with 5000 pound ballasts attached to the front and rear bumpers will have a roughly 50/50 weight distribution as do many BMWs straight out the factory. More relevant than "50/50" weight distribution are a) mass distribution, since weight "shifts" in turns and when accelerating/braking, and b) the polar moment of inertia. When accelerating and braking, no "50/50" BMW will have a "50/50" weight distribution, as the weight will be "transferred" to the rear and the front of the car, respectively.
 
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Originally Posted by mightymousetech
Huh? No, that is not true. It is because it is a modular engine, can be a 3,4 or 6 cylinder, transverse or longitudinal. Has nothing to do with balance. And you do not have to remove the engine, or tranny, to replace the chain. Unlike Audi, BMW can actually design an engine. Ha ha!


No, that is not true. The B47d--related to the B58 except 2 fewer cylinders and runs on diesel, not gasoline, requires the engine to be removed for the timing chain to be serviced. If a shorter block (2 fewer cylinders) requires engine out for timing chain service...I can't imagine doing the timing chain on a longer, 6-cylinder block with the engine in the car
wink.gif
.

From the BMW factory service manual: step 1 is remove engine:

https://www.newtis.info/tisv2/a/en/f22-218d-cou/repair-manuals/11-engine/11-31-camshaft/1VnYG9NVjL

The B58 similarly in the F31 340i similarly requires engine out according to the FSM:

https://www.newtis.info/tisv2/a/en/f31-340i-tou/repair-manuals/11-engine/11-31-camshaft/1VnZ3N8lKL

Now, you were saying? Something about how BMW knows how to design an engine?
 
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Originally Posted by Deontologist
Originally Posted by edyvw
Originally Posted by Deontologist
I can build a car with 2000 pounds in front of the front axle and 2000 pounds behind the rear axle and get a "perfect" 50/50 weight distribution.

But would you track such a car? Or would you prefer that the weight be more concentrated toward the center of the vehicle?

BMW's obsession with "weight distribution" is little more than marketing. It's not really about 50/50 front/rear. More important is where the weight is located.

BMW engine sits behind front wheels. I know what you referring to, but not sure how you came to the conclusion that BMW engine does not sit behind wheels or that weight is not between axles.


I came to that conclusion in my post? Nothing in my post says anything to that effect. I never said anything about where a BMW engine is located with regard to the axles or wheels. The point is that "50/50" can be achieved through many ways, some less optimal than others. In effect, claiming a "50/50" "weight distribution" is so vague as to be useless. A Toyota Camry with 5000 pound ballasts attached to the front and rear bumpers will have a roughly 50/50 weight distribution as do many BMWs straight out the factory. More relevant than "50/50" weight distribution are a) mass distribution, since weight "shifts" in turns and when accelerating/braking, and b) the polar moment of inertia. When accelerating and braking, no "50/50" BMW will have a "50/50" weight distribution, as the weight will be "transferred" to the rear and the front of the car, respectively.

Precisely what you said, I got exactly that out of your post, same from this one. You are assuming that BMW is claiming that for marketing purposes but you are not offering any evidence to the contrary. So, how much weight will be transferred? Also, not all BMW's have 50/50? Some diesels are heavier in front, for obvious reasons, and than some 4cyl have actually 48/52% distribution.
This would not contribute in any meaningful way to the distribution. Especially since B generation has big focus on reliability. Mechanical pump is back, for a very good reason, and only because of reliability. OFH is completely changed. If they are going with goal to improve reliability and cost (OFH) than putting chain in the back just to gain a little bit in what is already well balanced car does not make absolutely any sense. I would say modularity, particularly transverse applications are to "blame."
 
Originally Posted by edyvw
You are assuming that BMW is claiming that for marketing purposes but you are not offering any evidence to the contrary. So, how much weight will be transferred? Also, not all BMW's have 50/50? Some diesels are heavier in front, for obvious reasons, and than some 4cyl have actually 48/52% distribution.


Yes, I agree, not all BMWs have 50/50 weight distribution, that's why I said "many" BMWs have 50/50, not "all" in my post above.

Second, 50/50 is a marketing point. It's why you're repeating the phrase like a broken record player. BMW has brainwashed the masses about "50/50," which really is meaningless. And this ad solidifies the point of "50/50 weight distribution" being a marketing point.

https://www.youtube.com/watch?v=qobu0pJPHPQ

https://www.youtube.com/watch?v=ajjgTNKz9m4

Third, how much weight will be "transferred?" That would obviously depend on how hard you're jamming the gas or brake pedal. If you have a high-enough power engine, and mash the gas, you can get the front wheels completely off the ground, even if the car is "50/50" at a stop. For the last time, what's more important than static weight distribution and "50/50" is mass distribution. You can make your car have "50/50 weight distribution" right now; just attach a 1 ton ballast to the front and rear bumpers of your car. Of course, that's a meaningless exercise. More relevant is the placement of the mass; hence the number of high-performance and supercars relying on mid-engine configurations more than anything else--getting the majority of the mass in the center of the car is ideal.

Originally Posted by edyvw
I would say modularity, particularly transverse applications are to "blame."


Why would a "modularity" force the timing chain to be on the rear in a longitudinal application? These two concepts are unreleated. BMW placed the timing components on the rear at the expense of added weight and mass for one simple reason: mass distribution. As a matter of fact, BMW had to sacrifice some weight savings to place the timing components on the rear of the engine. Additional sound insulation had to be added along the firewall to keep occupants from complaining about noise. In short, BMW prioritized mass distribution over weight savings. Their ads talk about "weight distribution," but the engineers are actually worried about mass distribution (and NVH). Moving the timing components to the front of the engine would have resulted in weight savings (less sound insulation needed) but would have resulted in a slightly worse mass distribution as now all the timing components (VANOS, chain, tensioners, pulleys) are toward the nose of the car.
 
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Originally Posted by Deontologist
Originally Posted by edyvw
You are assuming that BMW is claiming that for marketing purposes but you are not offering any evidence to the contrary. So, how much weight will be transferred? Also, not all BMW's have 50/50? Some diesels are heavier in front, for obvious reasons, and than some 4cyl have actually 48/52% distribution.


Yes, I agree, not all BMWs have 50/50 weight distribution, that's why I said "many" BMWs have 50/50, not "all" in my post above.

Second, 50/50 is a marketing point. It's why you're repeating the phrase like a broken record player. BMW has brainwashed the masses about "50/50," which really is meaningless. And this ad solidifies the point of "50/50 weight distribution" being a marketing point.

https://www.youtube.com/watch?v=qobu0pJPHPQ

https://www.youtube.com/watch?v=ajjgTNKz9m4

Third, how much weight will be "transferred?" That would obviously depend on how hard you're jamming the gas or brake pedal. If you have a high-enough power engine, and mash the gas, you can get the front wheels completely off the ground, even if the car is "50/50" at a stop. For the last time, what's more important than static weight distribution and "50/50" is mass distribution. You can make your car have "50/50 weight distribution" right now; just attach a 1 ton ballast to the front and rear bumpers of your car. Of course, that's a meaningless exercise. More relevant is the placement of the mass; hence the number of high-performance and supercars relying on mid-engine configurations more than anything else--getting the majority of the mass in the center of the car is ideal.

Originally Posted by edyvw
I would say modularity, particularly transverse applications are to "blame."


Why would a "modularity" force the timing chain to be on the rear in a longitudinal application? These two concepts are unreleated. BMW placed the timing components on the rear at the expense of added weight and mass for one simple reason: mass distribution. As a matter of fact, BMW had to sacrifice some weight savings to place the timing components on the rear of the engine. Additional sound insulation had to be added along the firewall to keep occupants from complaining about noise. In short, BMW prioritized mass distribution over weight savings. Their ads talk about "weight distribution," but the engineers are actually worried about mass distribution (and NVH). Moving the timing components to the front of the engine would have resulted in weight savings (less sound insulation needed) but would have resulted in a slightly worse mass distribution as now all the timing components (VANOS, chain, tensioners, pulleys) are toward the nose of the car.

Have you actually driven back to back BMW and than Audi? Your arguments about marketing as main reason is simply laughable. You still do not offer any facts about how much weigh is transferred and same happens to cars with let's say 55/45%. I had recently opportunity to drave back to back 2014 Audi S4 that has that heavy front end and BMW 335i F30. While S4 is actually better vehicle IMO for day to day application, not just bcs of AWD, but other stuff, when cutting corners you always know that weight is in front as there is that understeer present. In BMW there is no such thing. You are throwig hypothetical and if you do not have anything concrete to say, maybe you should sit this out. Majority of the mass in BMW is between axles as I have already told you. BMW kicked out spare tire precisely bcs. of that reason. Is it going to be centered as mid-engine? No. But currently BMW is only luxury sports sedan with such weight distribution. This also includes bass speakers in floors etc. all to achieve that. I am again asking you, what is that weigh transfer?
As for other, modularity question, you and I have no idea exactly why BMW placed chain in the rear. You are hypothesizing. Do you have proof? No! I said "I would say" meaning I am guessing, but you are writing your post like you know facts, which you do not.
Do you have any PROOF BMW did that to achieve better weigh distribution? If not, it would help to not write your posts like you know something we do not, bcs. well, you do not.
 
Originally Posted by Deontologist
Originally Posted by edyvw
Originally Posted by Deontologist
I can build a car with 2000 pounds in front of the front axle and 2000 pounds behind the rear axle and get a "perfect" 50/50 weight distribution.

But would you track such a car? Or would you prefer that the weight be more concentrated toward the center of the vehicle?

BMW's obsession with "weight distribution" is little more than marketing. It's not really about 50/50 front/rear. More important is where the weight is located.

BMW engine sits behind front wheels. I know what you referring to, but not sure how you came to the conclusion that BMW engine does not sit behind wheels or that weight is not between axles.


I came to that conclusion in my post? Nothing in my post says anything to that effect. I never said anything about where a BMW engine is located with regard to the axles or wheels. The point is that "50/50" can be achieved through many ways, some less optimal than others. In effect, claiming a "50/50" "weight distribution" is so vague as to be useless. A Toyota Camry with 5000 pound ballasts attached to the front and rear bumpers will have a roughly 50/50 weight distribution as do many BMWs straight out the factory. More relevant than "50/50" weight distribution are a) mass distribution, since weight "shifts" in turns and when accelerating/braking, and b) the polar moment of inertia. When accelerating and braking, no "50/50" BMW will have a "50/50" weight distribution, as the weight will be "transferred" to the rear and the front of the car, respectively.


Do you remember when Porsche experimented with front side ballast in order to introduce some balance to the 911 due to the extreme rearward bias? I'm guessing you've never heard of under/oversteer? In any case your point is moot because while you're correct that "50/50" can be achieved in many ways there are only a few industry accepted ways of which none* include ballast other than my Porsche example.

*Racing regs not withstanding.
 
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Originally Posted by Deontologist
Originally Posted by edyvw
Not necessarily. BMW was able to achieve perfect distribution with older engines. 335i with N55 engine had distribution 49/51% in F30 model.


I can build a car with 2000 pounds in front of the front axle and 2000 pounds behind the rear axle and get a "perfect" 50/50 weight distribution.

But would you track such a car? Or would you prefer that the weight be more concentrated toward the center of the vehicle?

BMW's obsession with "weight distribution" is little more than marketing. It's not really about 50/50 front/rear. More important is where the weight is located.




Yes you can build a track car(one trick pony) however BMW builds a far more complex machine with way more variables including comfort, feel, performance for a price point. It laughable you consider your track building comparable to building a production vehicle.
 
Everyone is missing the point. Weight distribution is a useless metric. If I can create a 50/50 car in my driveway right now with nothing but cinder blocks, and the selling feature of some cars is 50/50, then there's something inadequate about the concept of 50/50 weight distribution. We need a better yardstick by which we can compare cars--a yardstick that can't be gamed so easily.

Static weight distribution is a very simple concept though, and one that people love to latch on. The relevant concept is the moment of interia. Unfortunately, high school physics doesn't cover this concept, and so people like to talk endlessly instead about "weight distribution" rather than what's actually on a BMW or Audi or Porsche designer's mind, which would be the moment of inertia.

A little bit of knowledge is a dangerous thing.
 
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Originally Posted by Deontologist
Originally Posted by andyd
School me please. What, pray tell, is the rationale behind a rear timing chain/belt? In the factory, the cabins are dropped onto the drive train The right way to take out an engine is on the sub-frame from underneath and then split off the engine or trans to service. KA- Ching!! and difficult to bodge behind the shop. The main reason I don't have a late model Ranger 4x4 is a rear cam drive 4.0L Take a good reliable little gas hog capable of 300K with little service and turn it into a grenade at 150K miles . A century of development going into push rod V engines. Then these OHC horror shows. What is the impetus to do this for Ford or BMW or any car maker?
coffee2.gif



Chain on back of engine, or toward the center of the car, is for weight distribution. Keeping that extra weight off the front/nose of the car has handling advantages. Of course that means you have to pull the engine for timing chain service...


Chain on back of engine is to quiet torsional vibration input to the chain, thereby improving its life.
 
Originally Posted by BMWTurboDzl
experimented with front side ballast in order to introduce some balance to the 911 due to the extreme rearward bias? I'm guessing you've never heard of under/oversteer? In any case your point is moot because while you're correct that "50/50" can be achieved in many ways there are only a few industry accepted ways of which none* include ballast other than my Porsche example.


So close but so far from the correct technical explanation of what Porsche was hoping to achieve. Over and understeering are directly related to the moment of inertia and mass distribution in the vehicle, not static weight distribution.
 
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