doug_999

ok, now that's funny - did you own a Supra? I did - and me and everyone else loved having our head gaskets replaced on a regular basis due to the #6 cyl issue...... I personally think the gurgling sound in the car and the no heat issues (this crap happens when you get air in the coolant) were fun -lots of fun.

edit: try a quick search on supra head gasket..... good reading..

Och

iTrader: (3)

Dude, I'm not saying that BMW's have tons of issues, I'm saying that BMW's with high output engines have tons of issues - M3, M5, 335 to name a few. Regular BMW's are fairly reliable, but are also rather mediocre when compared to the competition in pretty much every aspect - value, build and materials quality, performance and reliability.

Och

iTrader: (3)

Never heard of Supra having any of these issues, is that on the 2jz motor or the previous one?

mavericck

Just wondering if you have ever owned any of these cars that you like to put down?

tofu_house

iTrader: (2)

Och would never own a BMW.

bitkahuna

iTrader: (20)

greyBlitz - for each engine there's trade-offs and each manufacturer must decide what compromises to make. Some obvious factors:

HP
Torque curve (responsiveness)
Weight
Size
Fuel economy
Reliability
Cost
NVH (noise, vibration, harshness)

Sure that F1 engine makes amazing power but the trade-offs are cost and long term reliability (zero - it will probably be rebuilt after one race - not something a Lexus owner wants to deal with ).

The Lexus engines make 'good' power to achieve 'good' fuel economy, great reliability, reasonable cost, reasonable weight, flattish torque curves, and generally excellent NVH. With those priorities, it's not surprising you're not going to get 'M' type output.

You can find the trade-offs for any engine.

If you want high horsepower, high reliability, and not terrible fuel economy the engine is going to be complex and EXPENSIVE.

mavericck

Which explains everything....

picus

So what you're saying is you're more dialed into the 335i community than me? What do you consider common? 1%? 0.1%? 0.001%? We're talking a small percentage of the cars actually even produced without the secondary oil cooler, and of those an even smaller percent ever driven hard enough to overheat, and then an even smaller percent that actually *do* overheat. I've got timeslips from 8 track days this summer in my not oil cooler having auto with no overheats. Can it happen? Yep. Is it common? Not even close.

In any event, this thread is about ///M engines. I guess we'll have to see how the V8 goes. I would say the I6 in the e46 and m coupe has been of better than average reliability since the bearing issues early on.

RON430

Geez guys, for a relatively simple thread on M engine output, do we really have to get into yet another simple bimmer bash? The M engines have some definite tricks in them that produce their output. They don't necessarily have to be idolized nor demonized because of what they supply their customers.

One thing though, the notion that M motors get their benefit because they are "hand built" is laughable. Every engine from every manufacturer is hand built. As far as I know, no one has entirely automated, or even come close, the engine building process. I think what people might be inferring is "hand fitted" (blueprinted of sorts) rather than hand built. Blueprinting does help an engine produce better by operating at the specifications it was designed for. How long those fit tolerances last is anyone's guess. And if you have to replace a component, the advantage usually breaks down.

As most people here are not exactly the sharpest tool in the engineering drawer, just look back at that engine exploded diagram that was posted on the M engine and look at it from the perspective of a manufacturing or reliability engineer and think about all the components that are operating within amazingly tight tolerances four or five or six thousand times a minute. There are a lot of things that can go wrong. But it's not like bimmer is out on a limb on this, every engine out there has to completely, successfully function on such cycles. The fact that we do get the reliability we get with modern engines, bimmer or anyone, is really impressive. So all the technology in the bimmer may make some problems. All it takes is a vendor supplying one component that is not up to spec for any reason from wrong metallurgy to poor inspection, and you have a real problem in the field. At least if you are so disposed to want an engine with these outputs, bimmer offers it. If you don't want to buy it, you don't have to. But having the choice means that we as consumers all win. If you decide you want a Lexus - fine. If you decide you want an M - fine. At least if you have the bucks you can pick what you want. Just because Toyota opts for a bit lower cost assembly, consistency, and reliability instead of maximum output is nothing to be ashamed about. And bimmer is allowed to go after its customer with their product. Different strokes for different folks.

DaveGS4

iTrader: (2)

Guys knock off the personal commentary or exit this thread immediately.

Koma

iTrader: (3)

I guess I never thought about it enough. I guess all engines are hand built.

RON430

Too many fiddly little bits that would not be cost effectively performed with automation. The interesting thing is the consistency of the parts from the bin. Toyota spends its effort getting great consistency and less spread so the engines are more consistent. Other makers don't but often offer a specialty engine where the parts are not just grabbed off the shelf but measured and selected with tight tolerance. That alone can make one sweet running engine. It may be hard to get a Toyota/Lexus that is just quicker than the others but it is also hard to get one that is slower than the others.

greyBLITZ

iTrader: (2)

There are definitely some helpful posts here! It was best explained by bitkahuna and really answers my main purpose for this thread. Another member did mention the correlation between such output and the reliability, but I had no idea the extent of impact would be so great as in the F1 engines.

I'd hate to start up the fire again, I would appreciate if this thread was kept clean and helpful not only to myself, but to all members. In any case, what are some of the things (fuel economy, reliability, cost, weight, curves, NVH) that the M's have sacrificed in order to gain such high output? And to what extent have they compromised them? I mean, how badly does fuel economy suffer? Which aspects of the design have an impact on it? etc.

Again, I thank those members who have contributed meaningful and helpful posts. Please keep them coming

LexT

+1....
Carbon build up issue is the reason I got rid of my E39 M5 I bought it with 26K miles and @39K miles it had carbon build up.... I was like wtf....

thetopdog

There's not really that much to it, the recent M engines are the V10 in the M5 and M6 (507hp), the new V8 in the M3 (4 something, maybe 420 hp?), the old I6 in the M3/M Roadster (333hp) and the old V8 in the M5 (400hp).

All those engines rev high, have relatively low torque for their hp output, and produce peak torque at relatively high rpms. There's a lot of other factors determining performance, but basically BMW traded off peak/low end torque for high hp