For all those who would like some more horsepower in their 190SL, our in-house developed engine is the answer. The car looks no different from the outside; the extra muscle lurks under the bonnet.
It’s a sad fact that has been proven many times on the test bench: the standard 121 921 engine in the 190 SL does not meet its factory specification of 105 hp / 77kW. Its real power is generally between 86 and 89PS.
If you’d like your car to have a little more power, we build an engine with a 5-bearing crankshaft. The basic construction is the same, but it runs a lot quieter. We replace the crankshaft with a longer stroke version and fit special connecting rods and pistons from out tuning box of tricks. This immediately increases the cubic capacity and the weight saving results in more torque. We machine the flywheel and install a disc spring clutch that is easier to depress and handles the higher torque better. We make sure, of course, that everything is perfectly balanced. We fit the cylinder head with larger valves with narrower shafts, different valve springs and a camshaft more suited to the weight of the 190SL. A distributor with electronic ignition is fitted and the Solex PHH44 carburettor is treated to a new set of jets. The compression ratio stays the same at 8.8:1. A higher compression ratio wouldn’t be a problem, but it would reduce the service life of the engine and it wouldn’t run as smoothly.
The result is an honest 115 – 120 hp and a much more responsive engine.
The infamous hesitation when driving off is gone and there is now some real power at low revs.