I did some online research on this particular 1927 680 K model here in Delhi and this is what I found out.

In 1926 shortly after the merger, Daimler-Benz created the "K Type" supercharged model. "K" standing for "kurzer Radstand", i.e. short wheelbase.

The polished aluminum engine was a Single Overhead Camshaft, 6 cylinder, 6.25 liter or 381 cubic inch. It also featured a dual ignition. Without the supercharger engaged the model put out 110 hp. On engaging the compressor with a special clutch, power figure boosted to 160 hp. It had a top speed of 145 km/h or 90 mp/h.

In February 1928, the designations of all Mercedes-Benz passenger car models were changed by introducing the three digit capacity-based number thus turning the 24/100/140hp into 24/100/140hp type 630 or just type 630. This does not apply to Model "K" which was never called 630 K or 630 Model K.

However from October 1928 the regular-wheelbase version of the 24/100/140hp Type 630 was also offered with the more powerful Model K engine. This version which became dominant instead of the regular engined version immediately was called Type 630 with K-engine and is today called 630K informally - meaning 630 with K-engine.

This is a 630 with a K-engine




1926 Model K Transformable Torpedo


Another K Type


So I think the 680 K is a 630 with a K-engine or Type K.

I got some more information which I'll be posting shortly. In the meantime please give your valuable inputs/suggestions.

GS i see you have found yourself a new case to solve .

the pictures of the 630 posted by you do resemble the now in question 680k. if i do understand you right you say the car is a 630 which to some extent i would have to agree with you seeing the pictures and compareing the body style. the supercharged engine comes from the k engine that was fitted into the 630 and presumably the same engine went into the 680 too. so this car is actually a 630 with a k engine.
i do not understand then that why would the owner be confident and have documents to say that it is indeed a 680k.
when i inspected the engine bay i could not find any engine or chasis plate through which i could find out which model it actually is.
since you have done the research and i am feeling lazy to go indept and study right now could you tell me external ways of finding out which model it actually is. i dont think i would be allowed to open up the entire car and do a strip search.

Hmm.... you might just be right Gaurav, since the car seems to be pretty similar to the one in Delhi (apart from a few details) so it might just be right. But we would like the rest of the information you have before saying anything conclusive.

I knew this car well, use to belong to a family member. The car was purchased in Lucknow by the late Raja saheb of Bhinga. I recently met the late Raja saheb charming wife, now in her 80’s. She reconfirmed that the original colour was red, spoke about the spine tingling whine produced when the supercharger was engaged, the wooden box at the rear above the petrol tank in which they would keep the picnic hampers etc when they would go for drives & shikar. The late raja died in the late 30’s after which the car was not used for several years. The car was then given to the late raja brother in law who use to visit the UK racing circuit & hill climbs. This car was never raced in UK.

I have seen a letter from mercedes benz in the 80’s which states its is a mercedes benz open tourer, type K made in 1928. type 24/100/180. It has the larger 6.8 liter engine, 98mm x 150mm bore & stroke & not the 6.2 liter engine of the type K . This engine is similar to the 1928 type S but with a single carb. It has a lower hp rating of 100/180 & not 120/180 of type S.

I will post the engine nos , details later. the spare part manual of the type K has '24/100/140 PS' boldly written across the cover page which was printed in 1925.

sat

The car in question is NOT a 540k. Why he sold it could be best answered by him!

karl i was asking about the picture you posted. from one of the old pune rally at blue diamond hotel. wanted to know which model it is ?

SAT where did you pick this arcticle from. next time please delete the unwanted parts it makes it easier to read. thank you.

This excerpt has been taken from BS Motoring, July 2001. The 1927 Type K four-seater convertible featured in this article belongs to the Vijay Mallya Collection.

Legend has it that not one, not two, but six supercharged Mercedes-Benz Type Ks were participating in a hill climb. Was it a measure of confidence or a means to annihilate the competition? Nobody knows. The year was 1926, and taking part in hill climb competitions was a sure-fire method of proving engine performance and handling prowess. Grand Prix racing may have more glory, but hill climbs were the ones that were tougher... and more dangerous. Rushing into unpredictable curves at breakneck speeds in some of the most rudimentary pieces of machinery, hill climbs could be the differentiator between the men and the boys, or rather, the living and the dead.
The drivers of the supercharged Type Ks were preening with confidence, after all they had the most powerful cars around – apart from victory, was there any other outcome of the hill climb?
Sadly, there was one, and it wasn’t anything to do with success. Apparently, all the six Type Ks that participated met with severe accidents and were never to race again. How come? The reason, in retrospect, was simple. While horsepower was never scarce, the rest of the car couldn’t handle that sort of output. The steering couldn’t take the rest of the car through those tortuous curves and the drum brakes all around did not provide adequate stopping power to the near two-tonne hurtling missiles.

A loss like this could have put an end, or at least created a difficult-to-recover setback to Mercedes’ racing ambitions. But we are not talking about an ordinary car manufacturer here, nor are we talking about an ordinary chief engineer.
It was a tough but extremely down-to-earth man who took pre-WW II Mercedes cars to dizzying heights, by humbling competition and putting the fear of Germany into them. His name?

Dr Ferdinand Porsche. Dr Porsche’s list of achievements would read virtually like the technical history of the automobile, but for the moment, he was the head of engineering at Mercedes.
Unfazed by the Type K debacle, the fifty-year old Dr Porsche, with the support of the manufacturer, unleashed a series of dreaded machines wearing the three-pointed star on an unsuspecting world. Yes, we’re talking about the much superior and supremely capable S, SS, SSK and the SSKL Mercs, all based on the original Type K.
The lower and more rigid S (for Sport), with a bigger 6800 CC engine, twin carburettors and a supercharger with extra boost offered better handling than the Type K. It would go on to win the first German Grand Prix at the brand new Nurburgring track in July 1927, and a fellow Mercedes S would clock the fastest lap at the curvaceous circuit, a speed of almost 106 kph. This was followed by the legendary Rudi Caracciola’s win at the Ulster Tourist Trophy on a very wet day in 1929, defeating the favourites, a team of three 4½ litre ‘Blower’ Bentleys in his SS (Super Sport). Soon came the SSK (K for Kurz or short), which was developed with a short chassis and a larger ‘elephant’ blower – it rewrote history in hill climb races. Not content with success, the ultimate SSKL (L for Licht, or light) was launched – with a drilled chassis in an attempt to reduce weight – and it went gunning for glory.



Merger of equals
A historic event happened in 1926, when two rivals came together – Daimler and Benz merged to form Daimler-Benz. In spite of the pathetic state of the German economy, the board directed Dr Porsche to develop a premium touring car.
Dr Porsche obliged and created the first car to wear the Mercedes-Benz badge and the very first one, post merger, to carry a supercharger inside the hood – the 24/100/140 hp Type K. The doctor’s genius was evident in the engine construction – instead of the existing labour oriented engineering that used separately built-up steel cylinders, Porsche created a unitary cylinder block cast using light alloy with a cast iron cylinder head and a single overhead camshaft. Mated to a four-speed gearbox, the in-line six cylinder 6246 CC engine promised nothing less than 140 bhp with the supercharger singing.
The reason why it was called Type K is not for Kompressor but for Kurz, as the engine’s performance was way ahead for the rest of the body to catch up, and Dr Porsche had to shorten the wheelbase. The result? The world’s first genuine 100 mph (160 kph) touring car. In spite of a shortened chassis, the Type K would still earn the name ‘death trap,’ which might not surprise you.



Link: Long time no see - Mind blowing - Business Standard Motoring

GS if you see my posts no 76 and 82 i have asked karl the model of this perticular car that you have posted that belonged to poonawalla's and now with mallya. the reason being that both cars the one in delhi and this one UPS 954 are both different. they do look similar though. this one know i know is a type K but it still does not clarify if it is a 630 or 680.

Speedy the pics that Karl has posted is of VJM's 1927 Type K, which you can see in my last post (BS Motoring article).

I don't find much difference between VJM's and RM's car. Both appears to be a K type or 630 with a K-engine.
I am still trying to find out more details. Will update as and when I come across something.

In 1926/27 was there a 630/680 at all!! I have not come across any data showing production of 630/680 prior to '30s

in your research and investigation GS you forgot to read my post properly .
like i said the cars do look similar but there must be some points to differentiate the two. the similarities are many. the thing that has got me thinking and thinking alot is that the body styles are the same. engine capacities are the same and being K type engines. outer features are the same (dashboard etc). the owner insists it is a 680 while all arrows point it to be a 630.
like i pointed out earlier is there some way that the model can be pointed out. so when i do go to study the 680k i could look for them.

Yes there was Type 630 prior to 1930. Here is the brochure of 1929 Type 630.




Since the year is not mentioned here, you can goto the link mentioned below and search for Mercedes 1929. They have even mentioned 6.3 and 6.9 but the link is not working.
FCB Free Car Brochures

Thats what I am trying to find out Abhishek. From all the reading I have done till now, I think the car here in Delhi is a 630 with K-engine.

i too am getting convinced that it is a 630 with a k type engine. i am trying to find out more of the car too so that i can talk to the owner with enough material to prove that it is a 630. i doubt the owner even after being convinced would change his stance as it would become a prestige issue to start calling his car a 630k from a 680k.