Today we are fortunate to have a choice of carburettors for our 190 SL Mercedes but how do we make that choice and what are the driving factors to change?
The first question for you, the owner of the vehicle, to answer is: ‘how important is originality to you?’
If the answer is: ‘I value reliability and performance more than originality’, then you have an alternative.
In Period when the vehicles were ‘new’, the Solex 44PHH Carburettor was developed in conjunction with Mercedes for the 190 SL and performed very well in the driving conditions of the day. However, time has moved on and with it, such original components have worn and deteriorated. Additionally, over time, weak points in the initial design have become apparent.
One initial weak point in the design was the attachment of the carburettors to the engine. The design incorporated a stud fixing that was used not only to attach the aluminium inlet manifold but also the cast iron exhaust manifold. Over time, this mismatch of materials led to problems with air leakage at the inlet manifold to carburettor faces and poor idle issues. In Period Solex strengthened the rigidity of the mounting flanges a total of five different times during the production, to improve the integrity of this joint. However, air leakage in this area remains a common problem today and can account for poor running issues.
Wear is the other major factor with the original carburettors. Over time the throttle spindles ‘wear’ allowing movement in the butterfly of the carburettor which can cause ‘chattering’ of the butterfly physically wearing a groove in the casting bore of the carburettor. Both the issues can be rectified but require physical machining of the carburettor body to rectify – which is not a cheap solution.
Set Up and Complexity
The Solex Carburettor is quite complicated in the way it deals with Engine idle control – the adjustments only operate on one of the two barrels of the carburettor and this is not always understood when making adjustments and equally, can be time consuming to get a satisfactory setting especially if wear exists throughout the carburettor. Additionally, flat spots on acceleration are common and require careful adjustment of the accelerator pump linkages which are difficult to access with the carburettors in place. Finally, fuel level in the float chambers are more critical and can cause variations in fuel delivery, irrespective of Jet sizes.
Returning to the question of ‘how important is originality to you?‘
If the answer here is ‘very important above all else’, then you have already made your choice and are committed to life with the Solex Carbs. However, there are always ‘degrees of originality’. You could modify your car but keep and display the original parts or just retain them for future fitment when the time came to pass the car to a new custodian, thus benefitting from the improved driving experience whilst the vehicle was in your care.
What’s the Alternative?
We would advise Weber DCOE carburettors. These are widely available as a new product or kit of manifolds and associated parts that can be fitted and tuned to the individual’s car. Click here for more details. They are more readily understood and easier to set up initially. They are less prone to wear in the critical areas and offer the advantage of being more readily tuneable for today’s driving conditions and modern fuel types. They are a very cost-effective solution to the problem of worn Solex carburettors. Here, we should add that in order to set up any type of carburettor or fuel system correctly, the basic requirement of the engine being in good health is paramount and that basic settings such as ignition timing are correctly set.
We must remember that we are dealing with engines of over 50 years of age and that have had various degrees of use so all installations will be bespoke. Our technicians also use their experience to provide the best set up for you, the individual, carefully considering your aspirations and usage of the vehicle which is why when carrying out the conversion from Solex to Weber Carburettor here at SLSHOP, we carry out rolling road tuning and adjustments on every vehicle to which we fit Weber Carburettors. We will retain all the original parts and clean them ready for storage/re-fitment at a future date. We will, if required, report on their condition and give an estimate to refurbish prior to storage. To improve reliability further we would recommend considering upgrading the ignition system to more modern standards. Click here for more details.
Today we are fortunate to have a choice of carburettors for our 190 SL Mercedes but how do we make that choice and what are the driving factors to change?
The first question for you, the owner of the vehicle, to answer is: ‘how important is originality to you?’
If the answer is: ‘I value reliability and performance more than originality’, then you have an alternative.
In Period when the vehicles were ‘new’, the Solex 44PHH Carburettor was developed in conjunction with Mercedes for the 190 SL and performed very well in the driving conditions of the day. However, time has moved on and with it, such original components have worn and deteriorated. Additionally, over time, weak points in the initial design have become apparent.
One initial weak point in the design was the attachment of the carburettors to the engine. The design incorporated a stud fixing that was used not only to attach the aluminium inlet manifold but also the cast iron exhaust manifold. Over time, this mismatch of materials led to problems with air leakage at the inlet manifold to carburettor faces and poor idle issues. In Period Solex strengthened the rigidity of the mounting flanges a total of five different times during the production, to improve the integrity of this joint. However, air leakage in this area remains a common problem today and can account for poor running issues.
Wear is the other major factor with the original carburettors. Over time the throttle spindles ‘wear’ allowing movement in the butterfly of the carburettor which can cause ‘chattering’ of the butterfly physically wearing a groove in the casting bore of the carburettor. Both the issues can be rectified but require physical machining of the carburettor body to rectify – which is not a cheap solution.
Set Up and Complexity
The Solex Carburettor is quite complicated in the way it deals with Engine idle control – the adjustments only operate on one of the two barrels of the carburettor and this is not always understood when making adjustments and equally, can be time consuming to get a satisfactory setting especially if wear exists throughout the carburettor. Additionally, flat spots on acceleration are common and require careful adjustment of the accelerator pump linkages which are difficult to access with the carburettors in place. Finally, fuel level in the float chambers are more critical and can cause variations in fuel delivery, irrespective of Jet sizes.
Returning to the question of ‘how important is originality to you?‘
If the answer here is ‘very important above all else’, then you have already made your choice and are committed to life with the Solex Carbs. However, there are always ‘degrees of originality’. You could modify your car but keep and display the original parts or just retain them for future fitment when the time came to pass the car to a new custodian, thus benefitting from the improved driving experience whilst the vehicle was in your care.
What’s the Alternative?
We would advise Weber DCOE carburettors. These are widely available as a new product or kit of manifolds and associated parts that can be fitted and tuned to the individual’s car. Click here for more details. They are more readily understood and easier to set up initially. They are less prone to wear in the critical areas and offer the advantage of being more readily tuneable for today’s driving conditions and modern fuel types. They are a very cost-effective solution to the problem of worn Solex carburettors. Here, we should add that in order to set up any type of carburettor or fuel system correctly, the basic requirement of the engine being in good health is paramount and that basic settings such as ignition timing are correctly set.
We must remember that we are dealing with engines of over 50 years of age and that have had various degrees of use so all installations will be bespoke. Our technicians also use their experience to provide the best set up for you, the individual, carefully considering your aspirations and usage of the vehicle which is why when carrying out the conversion from Solex to Weber Carburettor here at SLSHOP, we carry out rolling road tuning and adjustments on every vehicle to which we fit Weber Carburettors. We will retain all the original parts and clean them ready for storage/re-fitment at a future date. We will, if required, report on their condition and give an estimate to refurbish prior to storage. To improve reliability further we would recommend considering upgrading the ignition system to more modern standards. Click here for more details.
More from Journal
CARE
THE ULTIMATE CERTIFIED SERVICING INVESTMENT PLAN
Your ownership journey matters to us, which is why we have created a simple certified servicing investment plan, tailored to your individual needs and aspirations.
Start investing today and our dedicated CARE team will work with you to increase the value and enjoyment you receive from your vehicle.
STAY IN TUNE WITH SLSHOP MOMENTS
As part of SLSHOP’s community of enthusiasts, you’ll be the first to hear about events and tours, key product offers, exciting stories from owners around the world and of course… our latest additions to the showroom. So, be the first to know and you might just sneak a car on your driveway or take your car’s condition to new heights with our exclusive replacement parts.
Or, visit SLSHOP Journal