How about supercharging a 280SL?

[Benz Dr.]

No, I sold the super charger to a guy in California. I think his last name is Cox.

  190SL's use a Judson system that draws through a small single barrel carb. The biggest problem is the way the system lines up with the intake manifold. It tends to run number 4 cylinder leaner than the rest which can cause problems over time.
190's are 8.8:1 which is quite a bit lower than a 280. Even at that compression they'll diesel like crazy on regular when shut off. They won't ping but they will run on. I've never seen an injected engine do this.

Daniel G Caron

[TR]

Walter, Norton -- As you recommended I've checked out Karl Middlehauve's website.  Good stuff!

Here's an interesting page from that site: http://www.mbgrand600.com/

Notice that Mr. Middlehauve reports an increase in horsepower of 76% and an increase of 51% in torque on a 600 with a 6.3 engine where he added a supercharger.  Here's those details, as measured at the rear wheels:

Std. HP: 196...Supercharged HP: 345...(increase: 149 HP, or +76%)
Std. Torque: 327...Supercharged Torque: 496...(increase: 169 Ft. Lb. of torque, or +51%)

Here's another link on his site about fuel management (re electronic fuel injection & supercharging): http://www.mbgrand600.com/


And Daniel -- Thanks very much for your response.

Tom in Boise

[TR]

Walter, Norton -- Per your input I've been in contact with Karl Middlehauve.  Amazing news ... he has just made this modification on a 280SE.

At Karl's request I am posting his response to my question:

<< Hi Tom,
 
We just have completed a MB 280SE sedan with a 4 speed, 1969 with a computerized fuel management system and a turbo installation.  The car performs well, and we will put it on an engine dyno to test how
much HP and Torque we gained.  We have a printout of the standard.

One more change we will make on the 280, a 6.3 rear axle ratio conversion, the standard 280 rear axle ratio is 4.15 to 2.82 on the 6.3.

I tell you its fun to drive the 280 now. If you are serious take a flight to Phila and drive the 280 SE Turbo

The conversion is not too difficult, a firm price we do not have but a ball park is $ 8-10K
 
Regards
Karl H. Middelhauve >>

[norton]

It's good to find out there's more people as sick as us, aint it[:p]

[TR]

Norton -- It is indeed.

I've asked Karl what the time reduction for 0-60mph is.  It will be interesting to get that info; also to learn what the HP and torque increases are after the car's been dyno'd.

[mdsalemi]

Hello Tom in boise again,

After listening to all this stuff, if "oomph" is all you are after best to consider an engine transplant.  Go to this month's Car & Driver and see what them boyz down in Georgia have done (and will do for $30k) with an old Mini.  Honda VTEC engine transplant.  Something like that (SLK engine?) will give you all the oomph you need.  If you start your own R&D project with superchargers and all the related stuff to get it to work, you are going to spend an awful lot of $$$ no matter what anyone says here, on an uncertain outcome--even if you achieve what you are looking for, how long will it last?  Listen to the good Doctor.  HALF the life in a 190SL with the tame Judson?  Melting pistons?  No thanks.  Get yourself an SLK engine or something similar and do a transplant.

PS.   Early Sunbeam Tigers had the Ford 260 in them I believe.  Poor Man's Cobra.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[TR]

Hi Michael -- Thanks for the kind input.  But nah, oomph ain't the only thing I'm after.  Just a touch more fun is all.  My CLK500 is capable of providing some fairly decent acceleration thrills.  But my passions are with the 280SL, and I'd appreciate a similar feeling from her when I step down.  I could be oh-so wrong about this, but I rather suspect the car is strong enough to handle a modification of the type Karl Middlehauve has described.  If not, I could always have the engine rebuild and then reinstall the original mechanical injection system.  I'll not rush into this, and might not do it ... but right now I'm leaning towards it.

I really appreciate all the inputs.

Tom

[mdsalemi]

Well Tom in Boise,

Another less costly thing you can try to mimic "supercharger" like performance is Nitrous Oxide Injection.  There's probably a plethora of information and kits available; my suggestion is that it would be a whole lot less engineering involved.

http://www.idavette.net/hib/nitrous.htm

Take a read, do a Google search, I'm sure you can come up with stuff.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[Raymond]

Why all that dangerous experimentation and trying to milk power out of a 35 year old engine?  You could easily blow it to hell.  Instead, you could pull the engine and set it aside for all of it's value as an original motor and replace it with an engine and transmission from a Nissan 300Z or a Mustang.  You would get new technology, ignition, fuel injection, high horsepower, big torque, and a MUCH better transmission.  All with readily available, lower cost parts.  Instead of adding weight to the front end, you might be reducing it with better susupension response too.  

IF you do make the car into a "muscle car" don't forget to upgrade the brakes.

Ray
'68 280SL 4-spd Coupe

[Cees Klumper]

Hello Ray - as far as the age of the engine is concerned; I think that so long as they are maintained properly and rebuilt when necessary, they should be and perform like brand new. The same goes for the whole car - old, yes, but not necessarily any less/weaker than when it was new. If an engine is rebuilt properly with the correct parts, tolerances etc., it will have the same performance characteristics and durability from when it first came off the assembly line. The question then, of whether the engine can accept a certain modification that adds power, is related to its design and durability, but not its age. I for one like my 280 SL to be in 'good-as-new' shape, and I like to drive it just like I tend to drive a new car. For example, I have taken it over long distances to Germany and I drive it at relatively high speeds (like 90 MPH) for prolonged periods of time.

BTW correct used M127, M120 and M130 engines are still available used from old sedan and coupe bodies, although this 'supply' will dry out over the years to come. A complete engine that is in ok or rebuildable shape should not be more than around $750, including the FI pump, ignition and other externals.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[norton]

Cees has a good point, buying another engine to use for the supercharger project is a good idea, Just like the Corvette guys do, when they want to go faster.  Buy a second engine, build it up for the supercharger, and keep th OG engine safe in the back of the garage. No use fraging the matching number engine. :x

[mdsalemi]

Gents,

As for the comments about a 35 year old engine, keep in mind that the age of the engine has more to do with the level of technical acheivement at the time, not the age of the engine per se.  Yes, a brand new rebuilt M130 motor as Cees points out should be the same today as it was in 1969 or whenever.  But that brand new M130 was designed for 170 HP give or take, and lets not forget that!  When you take that "new" M130 rebuilt, and then add something like a supercharger, oversized pistons, higher compression, nitrous oxide or any such contrivances, all bets are off.  That's why, as the good Dr. pointed out, the 190SL engine's life was cut in half with the Judson supercharger. However, the technology that went into the M130 engine is probably closer to 45 years old, and development on it began many years earlier--as derivatives of earlier engines.  To not take that into consideration when suggesting modern, higher HP modifications or additions will most certainly get one into trouble, which is what many of us are trying to say in the kindest possible manner.

If Supercharging were a panacea, every car would have it and we'd all be driving around with little blown 4-cylinder engines; we're not.  There's no free lunch.  Sure you can do it, it might take you an enormous amount of custom engineering to fit it all together, but there will be a price to pay besides money--absolutely, positively.  So, we are all waiting to hear the results.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[TR]

Guys -- Thoughtful comments all...thanks.

I too enjoy driving the 280SL as I would a new car.

My lead mechanic has experience with the M130, and is scheduled for training on the new SLR McLaren, so I'm relatively comfortable that he gets it relative to the possibilities, the risks, and the technology requirements of such an upgrade.  However, I'd not heard of anyone actually having done this sort of thing until Walter and Norton were kind enough to put me in contact with Karl Middlehauve. And now that Karl has just done a M130 perhaps we'll all know more before too long.  I sure look forward to those measured results from the performance testing that Karl has planned on his recently converted '69 280SE 4-spd.

My 280SL has a new engine in it now, with approx. 2,000 miles on it.  But we have kept the original; just like I have the original spare tire that came with the car.  As mentioned previously, we've gone to an awful lot of effort to get this '71 280SL 4-spd, with a Frigiking A/C (that blows amazingly cold air), to run cool during prolonged periods of idling on hot (100+F) days.  The guide line / scenario I gave my mechanics was this: "Picture yourself and your wife caught in stalled traffic in Phoenix during mid-afternoon in August...it's 110 degrees F, you have the top off and the sun is beating down...you have the old Frigiking running full blast...You've not progressed more than a mile in the past half hour ... And then your wife turns to you and says, 'with this wonderful Frigiking air conditioning system and these active ventilated seats I'm just so comfortable and glad to be here, and now I love this old Mercedes just as much as you do!' ... And then you look down at the 280SL's temperature gauge and reconfirm that the old gal (the car, not your wife) is holding temperature just like that new CLK500 is capable of doing in such conditions."

Hey, no problem for an air-conditioned '71 280SL, right?!  Well, I'm pleased to report that with many not terribly obvious modifications (to most people anyway) we are now there in terms of a M130 engine being able to "hold temperature" in such conditions.

Well, as mentioned, we won't move on this new project too quickly.  And perhaps not at all.  But it does seem that Karl has done some of us a great service in terms of his pioneering work when it comes to supercharging / turbocharging vintage Mercedes 6.3s and now a 280SE.  And if we do actually do this on the 280SL, but then things go terribly wrong (i.e., destroys the new engine), we will have our backup plan in place, including the old mechanical injection system that came with the car.

In the meantime I continue to dream/fantasize about the possibility of a 34 year old 280SL powered by a M130 that might reliably deliver acceleration performance close to that of a less than 1 year old CLK500.

[Shvegel]

I thought long and hard about forced induction(turbocharging in my case) my 280SL. I think that if you connected the altitude compensator of the injection pump with the air inlet upstream of the throttle body so that the fuel injection "sees" the increased air density you probably could achieve the proper enrichment but had I done this modification I would have opted to install a Bosch CIS injection system from a later 6 cyl Benz(if it is KE injection you would have to find a K basic setup from a 6 cyl Volvo or Delorean. If you coupled that system with a warm up regulator from a turbo Volvo 240 (circa 1981) which has a vacuum/boost enrichment feature you would be all set. Of course you would have to add an oxygen sensor and throttle switch for wide open throttle but those would be small items comparatively.
 As I said I thought long and hard and finally decided if I wanted a faster car that badly I would sell the 280 and buy a faster car.

[TR]

Thanks Shvegel.  Boy, do I understand about the "long & hard thinking" part.  It's interesting that you decided to not turbocharge your 280SL after a good deal of consideration.  I'll add your input into the decision stew, I'll also pass it along to my mechanic.  Thanks very much for your obviously well thought out comments.

Did you happen to check out those links that Norton and I posted to Karl Middlehauve's website where he has done supercharging (on 6.3s) and turbocharging (very recent on a '69 280SE)?

[TR]

Gents -- Thought you might be intersted in the latest brain-storm of my lead mechanic.  It occurred to him that perhaps people had supercharged / turbo-charged Datsun 240, 260, 280Z cars ... And we all know the genesis of those engines!  I haven't done the web searches about this, but he reports having learned quite a lot from the Datson Z-car crowd.

I thought his point was an interesting one.  He said it occurred to him that people probably wouldn't have a lot of reluctance when it comes to playing around with the old Datsun Z cars (which as I understand had engines whose roots where in the MB 6, e.g., M130); but because of the comparative rarity, value, etc. of W113s people would be (natuarally) much, much more reluctant to do such a thing.

The mind-experimentation continues...

[norton]

The Z's had carbs on them until the late 70's then electronic fuel injection, and I think the electronic injection is  the key to make it work, unless some one realy understands how the turbo diesel's boost reference the mechanical pumps.

[Ben]

Funny I actually read at the weekend that the current R34 Skylines engine block is remarkably similar to the MB in-line six, I knew the "Z" was related but it seems they still use the same basic design

The Skylines in Europe are tuneable to 1000BHP............dunno what the motor looks like sizewise but you never know !!

Regards,
Ben in Ireland.
'64 230SL 4sp.

[mdsalemi]

TR,

http://zhome.com/

Here is a good source for all that is "Z Car".  Read all the stuff and you'll find all kinds of reasons not to do things, and you'll find out things like how the harmonics of the 240Z engine snaps crankshafts in two at certain RPM's, how stock pistons crack like glass, and forged ones use oil like there's no tomorrow, etc.  You can be sure the M130 has issues as well--but you have not discovered them yet.

Also note that the king of Z cars was/is Bob Sharp of Bob Sharp Motors in Wilton Connecticut...if it can be done, they did it.  He raced Z cars for a long time in the 1970's and 1980's (with driver PAUL NEWMAN).  So, add that to your research department.

http://www.bobsharpnissan.com/

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[TR]

Guys -- Fun to think about, but plenty of consideration / studying will be done before, and if, changes are actually made.

My mechanic, who knows MB well from the M130 up through an '05 SL65 (and as mentioned he'll soon be going to training on the new SLR McLaren), will approach any such undertaking most gingerly.  That is in both his nature and mine.

It sounds to me like one would have to consider the whole package as opposed to attempting to piecemeal any aspect of it ... perhaps meaning a complete system of new EFI, advanced ignition control, as well the supercharger and associated air system, etc., etc.  We've been toying with this crazy notion for over a year now.  Who knows what the outcome might be ... but can you image the torque delivery (not to mention HP) from such an M130 engine, even tuned down for everyday driving?!

Tom

[n/a]

I would go low pressure turbo (10-15 PSI) with a large intercooler. Overall it would be smaller, easier to weld in & takes up so much less space. Turbos that are maintained and run right will not shorten engine life, my last turbo car had 325K miles on it when I sold it and was still going strong. Another plug for synthetic oil.

The injector pump has air sensors that should compensate for pressure as well as vaccum.

The hardest thing would be to have the right trim on the turbo, but there are lots of folks to help you there both on and off line. I can see this as a less than $1K project that takes you about 200 hours to get right.

Sounds like a fun project.

Regards, NRK

[TR]

NRK -- I've recently driven a friend's new SL65.  As you probably know that is the 600SL from AMG, which delivers 600+HP and 700+ ft lb of torque.  And I can testify this was an experience I'll not soon forget.  Obviously my '71 280SL is not even in the same realm in terms of performance, however, it may have just as much personality as that new SL65.

It's too bad AMG, or Kleeman, weren't around in the days of the W113 because I suspect they would have done something like you've outlined.  My lead mechanic will continue along with his "thought experiments" in regards to supercharging / turbo-charging, fuel delivery system, etc.  Today he removed the stock exhaust system and had a newly engineered replacement installed...went from the standard two small exhaust pipes, muffler & resonator arrangement to a single 3 inch pipe, single muffler, and twin 2-inch exhaust tips.  From an outward appearance not very noticeable, but we are anticipating a reasonable power improvement especially when she's pulling above 3,500 RPM.  It will be a while yet before everything else is back together...but I can't wait to test the combined effect of the new K&H air delivery package, elimination of the old clutch fan, and now this new exhaust system (which in itself appears to be a piece of artwork).

The standard exhaust system was gently removed and will be stored away for safe keeping.  We still have a several weeks of mechanical work ahead of us, then its back to the interior shop for a spruce-up.

When the new Metric engine went in, about 2K miles ago, we did not have the mechanical injection pump rebuilt ... just reinstalled it and it seems to work fine.  That injection pump has ~120,000 miles and 34 years on it.  I wonder how long it will be before a rebuild is needed.  I've never had the pleasure of paying for that experience, but my understanding is it ain't necessarily a pleasant event.  I wonder if that might be an opportune time to pull the original mechanical injection system off, store it safely away for posterity also, and then do the whole package in terms of a new fuel delivery / management & super/turbo charging in a nice and tidy fashion.  Hmmm... 'Tis a thought...

[Malc]

My thoughts (If the bank manager was up for it!)
The basic engine design is "strong"
I would
lower the compression
Change to electronic fuel injection
Use a turbo with a charge cooler rather than an inter cooler
Add an electric oil pump to circulate the oil after the engine is cut off.
add an oil-cooler

then I would have to look at the suspension and brake department to ensure they were up to a power increase
malc

[TR]

Malc -- Thanks for the idea input.  The mechanics have just gone through the entire suspension system.  The collective opinions are that the bottom-side of the car is up to it.

Interesting thought about lowering the compression.  Your idea will definitely be going into the consideration stew.

The weird thing about all of this is that I don't, and won't, drive the car particularly hard ... well, not often anyway.  I'd like it to continuing being a civilized touring or boulevard machine that can, on occassion, force one back into the seat.

[Malc]

You need to drop the compression otherwise the car will not run on modern fuels, unless you can get Avgas or run on some of the fuels available for racing (road legal in the UK but at £7 a litre it's abit steep)

You might want to go for distributorless ignition with a "3D" ECU and a knock sensor.

Just to throw another spanner in the works....

Why not buy a written off modern MB with either a turbocharged or compressor engine, stuff the engine in your car and keep the original engine??? that way your costs are reduced by "recycling" lots of the parts from the wrecked car, your still using available MB parts and less of a headache money-wise dealing with one off systems.

You could also use the gearbox if you wanted. Machining of adapter plates, make up a propshaft etc, would still be cheaper than the other route in MHO

I am doing this with a '74 BMW 3.0Csi where I am fitting stuff from a later M535......... I bought the whole car for less than it would cost to overhaul the Csi brakes with reconditioned parts!!!!
Ahh Fun
Malc
Malc