The Mercedes-Benz 190 SL profile

The Mercedes-Benz 190 SL, W121 series, is one of the most popular German classic cars amongst enthusiasts. As reported in the trade press last year, it has seen strong appreciation in the past 20 years.

As a true favourite of collectors, it is getting harder and harder to find a solid car – often leading to debate over if they are still a bargain after restoration. How do you get the most car for your money? Is that still possible?

There is no clear answer, with these vehicles in varying conditions. However, you can get closer to the truth if you ask yourself the right questions.

How do you become a happy Mercedes-Benz 190 SL owner?

Two ingredients seem essential for happy Mercedes-Benz 190 SL ownership: a suitable vehicle, and a workshop that knows something about your car. It is worthwhile looking for a garage near you that specialises in the car you want to buy. Without a local workshop you might not have much fun with your dream car in the long run. Some work you might be able to do yourself, but safety-relevant repairs should be carried out by a motor vehicle repair expert, for your own safety.

This raises two further questions: How do I know it is the right vehicle for me? How do I find a good workshop?

This is quite specific to your situation, something experienced daily in our workshop. You have to ask yourself how you want to display your classic. Are you obsessed with originality and prefer to look at the car than drive it? Or is driving fun at the forefront of your mind, and you are already planning your next road trip. This is where the areas of appearance, originality and technology come into play.

The purchase of a classic car as a restoration project should be carefully considered, since the high cost of parts can quickly overshoot your targeted budget. Before taking the plunge, try to make accurate and detailed cost estimates.

Things to consider on a Mercedes-Benz 190 SL

• The vehicle should be complete and at least drivable
• A Solex PHH 44 carburettor system should be installed, the correct engine with the matching cylinder head should be present. Compression 8.7: 1 or 8.8: 1
• A convertible top linkage should be available
• The bodywork is in reasonable condition
• A motor vehicle letter or a vehicle title with a customs certificate must be available

Before you buy a Mercedes-Benz 190 SL

Data Card

If you go to view a 190 SL, you should ask for the corresponding data card. This can be requested from Mercedes-Benz, but ideally it is already included in the documents for the vehicle. Using this card, it is possible to check for matching numbers and also original colours. Plenty of important information such as engine number, chassis number, paint code and equipment will be detailed as the car left the factory. Double check that the chassis number matches.

Engine

The right type of engine should be in the car, especially as sourcing a replacement can be costly. Mercedes 190 SLs were available in three variants: 121 921 water cover, 121 921 closed cylinder crankcase or 121 928. The compression value 8.8 corresponds to the first series of the cylinder crankcase 121 921 with water cover, while 8.7 indicates the later series 121 928 without a water cover. These values can be read on the outside near the water outlet of the cylinder head as a cast number. You will also find it on the left of the crankcase. It’s worth considering that due to age, the original engine may have been replaced.

In August 1961, the M 121 928 engine series replaced the M 121 921 series. The new engines from the end of the chassis number: 22122 were installed in the left-hand drive vehicles, and from 22285 in right-hand drive vehicles.

Appearance

The easiest thing would be to find a car with colour codes that match those in the data card, and a combination of paint and trim colours that you like. But what good does that do if that configuration just doesn’t work for you? Our advice for budding SL owners is not to be an originality junkie. It can be matching colours, but it does not need to be, especially as such cars have their price. However, it is important that the leather and paint were used in period and are in good condition.

Bodywork

If you do not want to send the car to a bodyshop immediately, you should make sure that the panel gaps remain the same throughout. We also strongly recommend lifting the car to check underneath. The middle section often harbours unpleasant surprises in the form of hard to reach access panels to the front and rear wings. There should actually be a gap on both side, which is filled by unpainted plastic piping.

Check the frame as it offers plenty of potential for rust. The mounts for suspension struts and shock absorbers on the rear axle are also magnets for corrosion, as is the entire front axle. Be sure to examine the usual suspects such as jacking points, headlamps, air intakes and all sheet metal fasteners.

The condition of the wooden cladding in the footwell under the carpets will be a good indicator of how well the car has been looked after. SL doors, bonnet and boot lids are made of aluminium and are thankfully rust-resistant. Even if the underbody looks good (and doesn’t match the rest of the vehicle because the underside appears fresh), there might be some patchwork going on. Both sides of the car should be mirrored, if this is not the case, improper sheets have been welded in.

Regarding the rust, you should also look inside the engine, under the battery in the battery box and in the recess of the brake servo. The water drain from the bonnet is located between the bulkhead plate on the door spar with the mounting plate in front of it – a perfect rust spot. Look at the body a little longer, you won’t regret it.

Carburettor

It is often said that twin-Weber carburettors would better suit this car, but Mercedes-Benz never delivered the 190 SL W 121 B II with these carburettors. Retrofitting tothe PHH 44 Solex carburettor including peripherals is expensive. Carburettor specialists or a restoration company can overhaul them and then install and adjust them without issue.

Transmission

The gearbox number stamped in the housing is also on the data card. This is important because the earlier Ponton model gearbox has the same housing. The Mercedes-Benz 190 SL has higher ratio first and third gears, something that you can’t otherwise tell from the outside.

Rear axle

There were four different rear axle ratios for the Mercedes-Benz 190 SL. The longest 1:3.7, 1:3.89 (very rare), 1:3.9 and the shortest 1:4.1. The gear ratio numbers are punched in under the oil filler screw on the rear axle housing. We recommend that driving enthusiasts go straight to the long ratio of 1: 3.7 if the rear axle needs to be replaced or overhauled. The engine noise when driving on the motorway is much more pleasant, however, driving uphill you might have to shift into a lower gear earlier. Don’t worry, you can easily get over any mountain even with a longer gear ratio!

Completeness and functionality

Make sure that the car is complete. Often vehicles are bought only to later find that a few things are missing, or have not been paid attention to. Spare parts are very expensive to procure, or in some cases with great difficulty. Take the time to look for the jack that is attached to the body in the trunk behind the spare wheel. Check the top, open and close it. The top linkage should work well in terms of mechanism and fit. Also, pay attention to the chrome and any costly damage on this component.

MERCEDES-BENZ 190 SL – CONCLUSION

Mercedes-Benz 190SLs might look similar at first glance, however, there are certain details that indicate a particular year of manufacture. There were celluloid sun visors in the early years, after which they were covered with leather. The number plate lights have changed from left and right next to the plate. Some very early SL examples came out of production without gill strips at all. The seating also changed from the bucket seats of the early SLs to those with a folding backrest.

Supposedly the last body change on the Mercedes-Benz 190 SL was on 31.08.1960 where case lid handles were altered. You should check this a little before buying so that you buy a vehicle that is as consistent with its model year as possible. We strongly recommend taking an expert with you.

Finding a good mercedes-Benz 190 SL workshop

You can count yourself lucky if you have found a workshop around the corner that is familiar with the W 121. Many owners have to put up with travelling or transporting the car to get the support they need for their prized Mercedes. It is best to find a business that regularly looks after these cars, with their expertise and and familiarity with the model invaluable. Ideally, you can also see some other Mercedes-Benz 190 SL on site to use as a reference for restoration.

Mechanical sympathy and attention to detail are essential traits of the right garage. Simple things like using the right mineral oil-based 20W50 engine oil when changing, is a clear and good sign. A good workshop will take care of the vehicle and take a closer look at the initial appointment, allowing for discussion around the current status and any recommendations. They should drive the car to the brake test bench to get the brake values ​​checked, and lifted to check the underside. Such things should be considered standard because they help both parties to get a feel for the SL.

Mercedes-Benz 190 SL Defects at a glance

1. Condition of the floor and frame, longitudinal and cross members, rear strut mounts, shock absorber domes, floor panel

2. Condition of cross tube at the front

3. Possible rust in headlamp bowls

4. Possible rust on the wheelarches

5. Gills, condition of chrome plating

6. Possible rust in the spatula access panel

7. Possible rust area behind any stone chipping

8. Possible rust spare wheel well

9. Possible rust on jacking points

10. Hardtop locking mechanism

11. Correct engine

12. Correct carburettors

Text Wallner Classic  Fotos Daimler AG, Mehringer Photography, Wallner Classic

Author: Classic Trader

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