450SE cf. 380SE (w116 cf w126)

[michaeld]

Curious about something:

In the S-class world, the w116s were "succeeded" by the w126s.  How do the 81-83 380SE/SELs  (M116.961 V8s) compare to the 76-80 450SE/SELs (M117.986 V8s)?  Are they pretty similar, or pretty different?

[s class]

The 380 has an aluminium block, so overhauling it is a very costly exercise.  It also has the much criticised single timing chain as opposed to traditional mercedes duplex.  The single chain is known to break and destroy the engine. 

In the 1980's when the W126 emerged, Mercedes touted the 380 as the "new generation" replacement for the 450, claiming it had lower mass and yet similar performance at reduced comsumption.  I'm not sure how true that is.  In any case a 450SEL vs a 380SEL is not apples and apples because the 450 has the old 3-speed box and the 380 has a much better 4 speed gearbox, so even if the engine outpit is lower, the car gave useful performance and driveability. 

On a related note, Mercedes listed the W126 500SEL (early ones) as the replacement for the 6.9!! - same arguements of lower mass but similar performance.  Now that is an even bigger stretch to believe. 

I actually have the original release propaganda documents showing photos of the different engines alongside these claims....

Ryan

[oscar]

Good Q michaeld. 

I may be wrong here but rather than 450 v 380, didn't the w116's 350 become the w126's 380 and the 450 become the 420? 
What of the aluminium block, what's the benefit and cost re overhaul?
Also, what's the chance of a w126 4-speed bolt on to a w116?

[Des]

Good Q michaeld. 

I may be wrong here but rather than 450 v 380, didn't the w116's 350 become the w126's 380 and the 450 become the 420? 
What of the aluminium block, what's the benefit and cost re overhaul?
Also, what's the chance of a w126 4-speed bolt on to a w116?

aluminium blocks are lighter, you can save around 50-100kg's over an equlivant cast block.

[s class]

When the W126 was first released, the only petrol engine options were  :

M110 280 twincam 6 cylinder continuing from the W116
M116 380 V8, developed from the M116 350, but publicised as a replacement for the M117 450
M117 500 V8, developed from the M117 450, but publicised as a replacement for the M100 6.9

When the model range was revised in about 1985, the following changes occured :

M??? 300 single cam 6 cylinder replacing the M110 280 (now called a 300SE)
M11? 420 V8 to replace the M116 380 V8.  I'm not sure if the 420 was an upratred 380, or a down rated 500
the M117 500 continued for a while, intil replaced shortly after by the M117 560.

The point of this is that the 380 and 420 were not alternatives to each other as they were not produced contemporaneously. 

As to the benefit or otherwise of aluminum blocks, perhaps styria is better qualified to answer, but my understanding is that aluminium offered reduced weight, better heat transfer properties, better resistance to corrosioin in the coolant passages.  One problem is encountered during overhaul - I'm under the impression that reboring an aluminium block isn't the same simple undertaking as with an iron block. 

Ryan

[cipha]

Specfications on the two motors:
                 450SE                  380SE
Bore and Stroke   92x85 mm   92x78.9 mm
Power                165 kW               145 kW
Torque                370 Nm               295 Nm


Thus the Iron block 450 is going to pull your car a whole lot faster and better than the 380 [maybe a bit noisier].

To get it going faster you could replace the 3 speed auto with the 380's 4 speeder, but I have heard from many that it is not as reliable as the older unit.

[Denis]

Hi fellows

I must say that I am not convinced by the MBZ claims of better W126 performance.

The new cars were going to be lighter and more economical through several mesures :
LIGHTER claim -alloy engines saved weight, but were much less durable
Results : the W126 280SE was 50 kg lighter than the W116 280SE - woooow, am I ever impressed at the new body shell 

MORE ECONOMICAL claim - better gearboxes helped
Results : small improvements, the better gearboxes came with numerically lower rear axle ratios so you need the extra gears just to offset the performance loss with the axle ratios.

By today's standards, nobody would call the W126 a NEW car over the W116. It is a second-generation W116. OTOH there is a myriad of small improvements on the W126 and one really wonders why they were not part of the W116 to start with (drainage lines, various routings of wires, etc).

In retrospect, a W116 with better gearbox/axle ratio selections would have offset the need for the W126 by several years ...

Denis

Paris, France

[michaeld]

Here's a post I copied and pasted from Mercedesshop.com/shopforum on the subject of the so-called superiority of aluminum engines: http://www.mercedesshop.com/shopforum/showthread.php?t=147637&page=2

You kind of need to read the entire thread to truly understand the conversation, but basically someone brought up the "aluminum = better" argument, and I responded thusly:

(For what it's worth, I KNOW Styria will be very pleased to read what I say about his beloved 6.9s here).

BTW, my last post to the aforementioned thread provides a number of pretty good quotes citing the magnificence of w116s.

Okay, here goes:



Ok. Now I will try to explain.

Here are some excerpts from an LA Times article that I find illustrative:

"But not everybody with aluminum engines is so enamored. The history of aluminum-block engines is full of disappointment and premature failure owing to warped cylinder heads, leaking seals, blown gaskets and worn cylinders."

"Despite advances in aluminum engines, they still cannot withstand overheating, contaminated oil or dirty coolant the way cast-iron blocks can, says Bill Whitney, president of Prestige Engine Co., a Dallas specialist in remanufacturing aluminum-block engines.
"They are definitely subject to premature failure," he says. "Aluminum-block engines are subject to blown intake and exhaust gaskets. They are the weak links in the chain.""

(Source: Los Angeles Times, October 18, 2000, "Iron's days are numbered as auto makers cast their lot with aluminum"). The article specifically states that the move toward aluminum today is due to improved fuel economy from reducing weight, rather than any move to increase performance or durability.

There are a number of durability issues that aluminum suffers. Cast iron has relatively low corrosion rates in automobile engines. Aluminum, by contrast, has one of the highest oxidation potentials of any metal. Aluminum is particularly sensitive to a process called erosion-corrosion where a rapidly flowing fluid can remove the protective oxide layer. The corrosion of aluminum can be quite a problem - a problem which is simply nonexistent with iron. There are other problems caused by aluminum, such as the fact that aluminum salts will precipitate out of solution in the cooler parts of the coolant system.

Iron is a stronger metal than aluminum. It has a higher melting point. It has a higher density. And it has superior stiffness and wear characteristics. These are simply scientific facts. Aluminum alloys are typically only around one-third as stiff as cast iron. Also, aluminum has a much higher coefficient of thermal expansion. All of this means that distortion with both heat and stress is a bigger potential issue with an aluminum-block engine. Which is precisely why the LA Times article makes the comments that it makes.

I haven't even mentioned practical issues such as the ABSOLUTE necessity to use torque wrenches on every single aluminum application due to the constant fear of stripping. And anyone who would rather rebuild an aluminum engine than an iron one is just plain nuts.

As for the fact that Ferrari uses aluminum blocks, show me a Ferrari that's racked up a million miles, and maybe I'll get impressed. Race cars use the lightest materials, true; but they also go through a heck of a lot of engines in their races. I was surprised to learn how many automobiles - foreign ones included - continue to use iron in their engines today. Where weight isn't an issue, iron continues to be the metal of choice. Fuel economy standards are forcing the transition to aluminum, not improved "quality."

As for the suspension elements in the 80's Benzes vs the older ones, I'll have to check. I was pleasantly surprised when I read that the zero offset suspension pioneered in my 450SEL continues to be used in MBz today. It also featured anti-squat rear and anti-dive front suspensions that were way ahead of the times. I'm really not sure what the 80's cars did to dramatically improve from the 70's.

Frankly, your comment about using iron instead of aluminum being "cheap" strikes me as being extreme to the point of being a bit bizarre, as such a position would demand the conclusion that Mercedes-Benzes were "cheaply made" until the 80's. If anything, the actual situation is exactly opposite! The older Benzes were driven by engineering far more than by accounting or marketing. The 75-79 6.9s - ridicuously expensive and incredibly engineered - used iron blocks. Cheap? These cars cost significantly more than Rolls Royces!!! If aluminum performed better in that car, you can bet your britches that the engineers would have used aluminum! The fact that they did not should tell you something.

My opinion of modern cars is going down. The increasing use of computers and electronics WITHOUT QUESTION means that they will have shorter lifespans than the older cars. Why? Because they require more and more highly specialized equipment and sophisticated mechanics (removing the possibility of DIY) that will increasingly drive up labor prices far beyond the value of the cars as they age. In 15 years, a lot of expensive new cars will be junk.

As for my comment about motorcycles that you brought up in your post, go to a motorcycle dealer that sells cruiser bikes (BMW does not make a cruiser; try HD, Honda, Kawasaki, Yamaha) and ask them why the cruiser bikes are so much heavier than the sport bikes. Their answer will get to the point I was making about weight and ride quality.

[Denis]

Hi fellows

I have a slight point of disagreement with styria. I do not believe that he W126 was a major weight improvement over the W116.

The weight of a W126 500SE is a mere 40 kg less than my 350SE and probably less than 95 kg under a 450SE - a measurable but not major improvement at these overall vehicule weights

I think that some of you lucky (but that is also debatable) 6.9 owners have a tendency to see things though that great engine's car version specs.

The M100 block MAY have had a future if an aluminum block had been made for it but that great engine is what it is : an early attempt at an OHV V8 by a company with NO experience in building one. As is safe to do then, when in doubt, OVERBUILD, meaning...overweight. The long skirted cylinder block is a telltale of an early design.

I once read that engines like the early Lincoln 430 cubic inch V8 and Chrysler 392 hemi were incredibly heavy for the same reason ... when in doubt, OVERBUILD 

As it were the M100 was on the drawing boards in 1960..while the M116/M117 was, later...some lessons were applied.

Down with Italy, go Zidane go !!!


Denis

Paris, France

[Denis]

Hi Styria

quote]500SEL   1655kgs.   450SEL   1765kgs.[/quote]

Close to my figure and only 7% lighter 

I get my engine info on the alloy M116/117  from a local (serious) rebuilder and he has no kind words about these engines when they get really out of specs, especially not the 4.2 litre.

Maybe the old Buick/Rover engine was OK but most of the alloy block engines of the 60-70s were problematic. Alloy blocks without steel liners were not durable, silicon impregnated cylinders could be absolute horrors (Chevolet Vega) but then, the old Alfas were good 

Nobody questions alloy block durability today (but we NOW think that 250 000 km is incredible durability)
In any case, that iron M117 block has a reputation all its own...the LASTER 

M100s could be eternal given owner TLC

Denis

Paris, France

[carl888]

In the early 80's I was lucky to drive a 450 SEL (1980 Australian version) and my dad's 1983 380 SEL back to back.  The 380 was faster in a straight line up to about 120 km/h and then to about 180 there was nothing to split them, after 180, the 380 would pull away again and it went about 10 km/h faster.   

I did prefer the 450 though, the engine had a bit more low down torque which made it's progress a little more dignified and relaxed.  It also sounded nice, a soft V8 below that the 380 lacked.  The gearchanges particularly were far superior in the 450.  The 380 was pretty jerky in that respect.  The 380 was a pig to start when hot too, this was an issue that was never resolved (Dad bought it new and it did it from day one).  In 1986 he traded it for a 420 SEL which was difficult to believe they were from the same family.  The 420 in terms of refinement was a quantun leap ahead of the 380.  Not to mention the engine was turning over at just 2,000 rpm at 100 km/h as opposed to the 2,850 of the 380 and 450.  The Bosch KE jetronic cured the dreadful throttle response of the 380 and electronic regulation of the gearchanges ensured the shifts were seamless.   

The fuel consumption of the 380 and 450 was not that different, the 380 being about 10-15% better in the 380 but the 420 was a better by a huge margin.  I can't recall exactly, but it was like 25% better.

Regards,

Carl.

[michaeld]

An interesting conversation, this, w/ some pretty good insights both from you mechanic-types as well as those of you who've driven the 80's Benzes.

Denis said something ("Nobody questions alloy block durability today"), that does not entirely mesh w/ the Oct 18 2000 LA Times article I cited.  There still seem to be plenty of good reasons for saying that iron blocks very much continue to have their place in the world.  [Also, tell me if I'm wrong, but it seems to me that I read somewhere that MBz forged their blocks, rather than casting them, which resulted in a much superior metalurgical process].  Aluminum offers weight reduction - good for pure performance - and improved fuel economy; but after that, it has a LOT of shortcomings compared to good old iron (as detailed in my post).

I can forgive MBz for going to aluminum blocks, because it made sense given the realities of both the governmental regs and the demands of the marketplace.  But there's another issue that comes to mind: what did the 126s do to genuinely "move the ball forward" from the w116s?  There MUST have been something!?!?  Or not?

I CAN tell you this: I'd buy a 126.  But as we get enter the 1990s, I'd be loath to purchase a MBz that would likely face repair bills that would boggle the imagination.  What do you think?  Am I wrong about this?

In any event, allow me to now post to this forum a post I wrote to the same thread as the one above.  I do my best to detail what made w116s so special (though I focus on the 450SE/SELs).  What did we see in the 126s that the 116s didn't do well?

Here's the post:


Mark,
I basically agree with everything you said - to a point. The difference is that I think more highly of the late 70's cars than you do.

There is NO question that engine performance (here I tip my hat to Dan) suffered in all cars as a result of the US 1970 Clean Air Act. The 1973 oil embargo was another atom bomb for a reeling car industry. The US 5 mph bumpers are clearly less attractive than the Euro bumpers of the same period. And on top of all that, Mercedes-Benz found itself additionally challenged by currency issues that made their cars more expensive relative to US dollars.

And yes, I dare say that Stuttgart was realizing where it's high end "luxury" sales were coming from during this period, and began building features for the wealthier American market segment (power windows, power doorlocks, and the now infamous ACC system).

I agree that all of the above is true.

But I DON'T think that Mercedes-Benz "old world" quality simply ceased to exist in 1974 (nor, apparently, does Mark). Rather, I think one can see the beginnings of a trend that began to "stretch" the elastic nature of that "old world" quality commitment. It got stretched more and more, until (IMHO) it snapped altogether. Over the last decade, fewer and fewer Benzes even bear the label, "Made in Germany."

In the mid-70's, Stuttgart was still the place where engineers - and not marketers - dictated how cars were made. And I dare say that MBz ALWAYS loved it's hi-tech gadget frills (such as the air suspension on the 300SEL 6.3s that reappeared as the hydropneumatic suspension on the 6.9s).

How do I respond to defend my own claim - given what I've acknowledged about the 70's - that the w116s deserve a LOT more credit than they get?
1) Because MBz desired to maintain a certain level of MBz performance in spite of the smog laws, they increased the volume of the 3.5L engines to create the M117 4.5L. The final product was slightly reduced in hp - due to running a hp-robbing smog pump - but it had more torque. The M117 engine and the 722.0 tranny are virtually industructible. According to the book, Mercedes-Benz: the first hundred years, the post smog engines managed to keep up, saying, "But they were hardly slow: the US 450SE could cruise at 120 mph with 10 mph in reserve, and the traditional 0-60 sprint took about 10 seconds" (p 223). I know that other cars are faster, but that really is more than enough for me.
2) I am personally glad that the compression is higher than the earlier 8:1, because it enables me to run just peachy dandy on 87 octane.
3) I wrote a post on another forum (w116.org) titled, "How to make your US 5mph bumper more beautiful than a Euro bumper" after putting my car into reverse and slamming into a concrete pole. I LOVE my 5 mph bumpers!  Anything else would not have been adequate to protect my car (amazingly, there was no damage at ALL). Euro bumper lovers can and will sneer at us poor 5 mph slobs - until a fender bender. Recently a fellow w116 member wrote a post "How to make a Euro bumper uglier than a US 5 mph bumper" following a minor accident. I'll keep my bumper, thank you!
4) I believe that the anti-squat rear end w/ its semi-trailing arm, and the zero offset anti-dive front end wishbone suspension can only be described as massive improvements that have set the stage for modern suspensions and at the same time have performed and endured extremely well.
5) As for the power windows, vacuum doorlocks, and dreaded ACC, what can I do but hang my head in shame? These are the things that go out most in these cars, aren't they? I myself HATE the vacuum locks. I worry over my tempermental ACC. But fortunately, recent aftermarketers have largely freed us of the ACC curse, by providing reasonably-priced alternative systems that have all the marvelous benefits of the ACC without the $$$ headaches. As for cruise control, I LOVE my cruise control!
6) I've seen enough older Benzes to know that - aside from the 600s (which are simply magnificent beyond description) - my 77 450SEL doesn't give up a whole lot in terms of build quality OR coachwork. I love my wood and my leather. There's a small bit more wood in some of the older models, but we're talking shades of a degree here. And when I shut the doors, I hear the same bank-vault-door sound that I've heard in 108s.
7) One of the indisputable facts about a comparison between 108s/109s and 116s is that there are a LOT more 116s in good condition, and they are much cheaper to buy. Bad for a collector, perhaps; AWESOME for a buyer/driver.
the 70s w116s have the classic look of the previous Benzes, and yet a modern styling that prevents them from looking "old."
9) The K-Jet injection. Carburetion kills cars by sloshing gas (a solvent) over the cylinder walls. And the K-Jet is simpler and more easily serviced than the earlier L-Jet.
10) In claiming one era is "best" for classic cars, I believe we are looking for that era which preserves the best of the old while introducing the best of the new. And I believe the w116s are serious contenders for the title given this parameter.


Let me provide some quotes about my beloved 450SE/SELs.

"Any complaints one has with the concept must be weighted against the overall package and the design intent. Mercedes engineers set out to make precisely the car they designed with virtually no expense spared. You probably think that's what all manufacturers do, but there's many a change between drawing board and release day. the 450SE is a car of little comprimise" ("Mercedes Benz 450SE: sophisticated excellence," Modern Motor, June 1975).

"The w116 structure was the latest development of D-B's patented "rigid passenger cell/deformable extremity" construction... their w116 is a really substantive attack on the problem of automotive safety. I consider the w116 the best combination of active (accident avoiding) and passive (protection in a crash) safety yet devised for a production car" (Mercedes-Benz: the first hundred years, pp 223-224).

"One of the most popular Mercedes of recent years in the US, the 450SEL of 1973-1980 was termed the best sedan in the world" (ibid, 199).

MBz: the first hundred years quotes Road & Track as saying, "For 10/10 driving, a 911 Porsche or a Maserati Bora will corner faster. But in exchange for their ultimate cornering ability one must accept nercous, twitchy behavior at speed on all but the smoothest of surfaces... As a roadgoing sedan the 450 has no equal. It require a rethink of usual driving habits. That dip at the end of the block where all mortal cars bottom? Forget it. That chatter-bump curve where most rear ends break loose? It's gone. That bump you always slow down and brace yourself for? It never happens... the truth will come out, so here it is: The Mercedes 450SE is the best sedan in the world" (ibid, 224)

Continuing right from the above sentence, the book goes on: "And notwithstanding the latest w126 models, there are a good many people who still agree with that assessment. Summarized Graham Robson: "Everything known about safety engineering, and 70 accumulated years of passenger car experience by D-B, went into these S-class sedans. They were so quiet and refined, so roadworthy, so fast and - as experience proved - so very reliable that it was going to be difficult to make dramatic improvements when the time came to replace them" (ibid, 224).

Now a couple quotes re: the engine and tranny of these 70's V8s.

"But beyond these attributes, most of these 1972-1989 V-8-powered SLs have engines that are just about unburstable.
"I've driven a number of early 4.5-liter SLs with 750,000 or more on their engines," said Rugg. "At a million miles they get a little edgy". That may be stretching things just a bit, according to Cunha and Marx. But both agree the iron-block V-8s are exceptionally long-lived. "Around 350,000 before a bottom-end overhaul isn't unrealistic," said Cunha. "The top end is often good for 180,000-240,000 miles." And from Marx, "I have some customers with at least 300,000 miles on their cars and the engines haven't even needed valve jobs" ("MERCEDES-BENZ 350 / 450 / 380 / 560 SLs: Status-symbol bargains for the not-so rich and famous," by PETER BOHR).

"Despite V8 power this big 'Benz is more a cruiser than a rocketship. Acceleration is languid until 1700-plus kilograms gets fully into stride as this is a car that thrives on wide open spaces and steep climbs... Cars that haven't enjoyed a recent transmission overhaul are likely to be a little sluggish but manual shifting through the unique gate compensates for tardy kickdown and when worked hard the 'Benz auto shows why it was regarded as the best of its time" ("Class Distinction, buyers guide," Unique Cars, Sep 1999).

It's a measure of the W116's strength that, despite it complexity, relatively little goes seriously wrong with it mechanically. That's not to say that it will never break, or that serious problems won't cost big money to fix, but we're not talking XJ12's, or ageing DBS V8s here" ("Guten Price Tag: An S-Class Mercedes is the luxury bargain of the century," Your Classic, March 1994).

Why did I go to all this trouble? Because I'm a long-winded son-of-a-gun, yes . But mainly because 70's cars seem to get no respect at all. And the 70s Benzes deserve respect. They were, and are, outstanding cars. People think of 70's cars and think only of smog regs, detuned engines, and big bumpers. Yeah, the w116s had all those things, but I believe I've shown they are nevertheless magnificent cars in their own right. I'd like classic Benz lovers to look a little deeper than the proverbial slangs against the 1970s and recognize that these are some truly good cars.
Mike

BTW, if anyone would like to go to the trouble of compiling quotes from various sources documenting how marvellous their own cars are, PLEASE DO!!! I for one would love to read them!