DASHOCKER

iTrader: (2)

Yes
This is true and some folks run with this notion. I am not one of them.

Getting back to the M engines, as mentioned, those engines are engineering marvels. How many production motors have individual throttle butterflies for each individual cylinder?? Add to that, BMW's use of Variable valve timing Double Vanos.




The double vanos in BMW vehicles flattens the torque curve, improves low rpm power, and widens the powerband for a given set of camshafts. At the same time, the torque does not fall off as quickly past the horsepower peak like in some othe VVT systems.

Another advantage of double vanos is that the system controls the flow of hot exhaust gases into the intake manifold individually no matter what the operating condition. All of this is the perfect recipe for efficient high performance motors.

insider

What you have to keep in mind is that horsepower is nothing more than torque. So 100 lb/tq at 3,000 rpm is always going to equal the same hp no matter what engine. If the engine can hold that 100 lb/tq at say 4,000 rpm, than it will produce more hp. The higher the RPM the engine can hold that 100lb/ft, than the more hp it will be making. That's what BMW M engines do. They produce torque up at high rpm's, that equals the high hp.

LexFather

M engines are fantastic, I wouldn't go so far as to call them "marvels". They always have problems and well, they should, they are high strung engines.

Just recently the E39 M5 has huge carbon desosit issues (look at some of those values on Autotrader or read the M5 forums, 6k-12k for a new engine depending if BMW foots some of the bill) or even the E46 first run of engines had huge issues, where BMW replaced the entire engine and offered extended warrenties.

I think the engines are incredible but I am not oblivious there are issues.

RON430

Great point. Mention has already been made of F1 engines but wander down to your local drag strip and see either a Top Fuel or Funny car and, while supercharged, think about three times the displacement of an F1 car but maybe ten times the hp - 7 to 8,000hp. But they are virtually rebuilt after every what, minute of operation? Engines are always compromises and BMW doesn't do that any better than anyone else. They are just willing to skew the compromises for that high specific output. But there is a price to pay. Besides carbon fouling at lower rpms or the crappy gas that we have to contend with, they place great stresses on things like engine lubrication. Unfortunately,these are heat engines and with that high output comes some impressive temperatures to be dealt with. Race cars can be a real hoot but there is a reason why they aren't so much fun on the street. Idling something with a lumpy cam that really wants to wind isn't a lot of fun - watch the NASCAR guys try to get in and out of the pits without stalling, it isn't easy. Much of BMW's technology, such as the double VANOS is an approach to specifically address those issues. They are marvelous and marvelously complex. It is nice to have the opportunity to get one if that floats your boat.

Och

iTrader: (3)

Should they? Well, look at some of Honda's stuff, S2K, NSX, ITR - they have similar hp/l output to the BMW M engines, without any of the BMW problems. Too bad Honda has dropped the ball in the recent years.

Whenever you hear of any BMW high output engine, inlcuding the 335, there are always some major issues. I strongly believe that BMW doesn't engineer these engines properly, instead they just overclock them and sacrifice reliability.

LexFather

^^^ I mean I've driven, ridden in them and as stated before, spoken to multiple mechanics, BMW and independent shops. They really really support BMWs as some of the best if not best engines around.

You just have to have the $$$$ to maintain them. I've driven tons of BMWs or been in one, even an E36 I-4 318 and it never felt underpowered or wheezy.

Look at how they continue to produce I-6 engines, while everyone moves to V-6s..... You have to love the stubbornness.

doug_999

Such as? Do tell please - and hold on the M3 bearing issues - that was resolved way back when.

Och

iTrader: (3)

Such as??? Please man, the 335 is a freaking joke with all the overheating issues. It can't even hold up to the 15 year old Supra, which had the same size engine, similar turbo setup, and similar power output, without any issues.

And M3 has more than just bearing issues.

E-Z ES300

I like the interest in this thread!! I'm even learning much about BMW's here, yeah they were real big about trying to stay away from FI.. now the 335 changed that i guess... OH YAH CHECK THE SIG

LexFather

BMWs had turbos in the 1970s One was a (I believe) turbo 3.5 liter V-6 in the 7 series. Instead of calling it a 735, they called it the 745 because they felt the turbos= 4.5 liters of displacement if it was naturally aspirated.

BMW then dropped turbos for all N/A power and as of late with Benz using Turbo and S/C for unbelievable levels of power, BMWs stance was "we are about purity and will not turbo".

Well with all the power wars, even with the Japanese involved, that had to change.

spwolf

ehm, yes, M3 has had some issues (and then again owners probably abused it) and 335i is having some issues too... I am sure you check up on bimmer forums once in a while, eh?

Lets not pretend everything is fine in german land.

We have our own share of issues (Tranny ES350, rattles in other models), but BMW does as well, and if you check (for instance) 335i, not only it has rattles it also has trannies blown, ecu's being replaced, engines overheating, fuel pumps issues, electrics etc, etc...

Search for "problems" on IS boards and on 3 series boards. I assure you that you will get wastly different results.

There is reason Lexus was 6th in Consumer Reports and BMW was 18th.

DASHOCKER

iTrader: (2)

This says it all.

LexFather

lol, not sure what happened, I did not write that, I meant to say I have been in tons/driven tons and the 318 never felt underpowered or wheezy. Weird.

I know much more about BMW than you, so take some time to read my posts in this thread preaching and giving props to the brand.

DASHOCKER

iTrader: (2)

LOL. Really I guess you were around in the early 70's??? No need for me to read jargon from one who has no experience with the cars..

LexFather

Are you reading anything in this thread or jumping to conclusions again? I said I didn't write that and I'm investigating it.

Every single post of mine in this thread has been fair to the brand and helping Blitz out about BMW and the "M" engine history.