Mercedes-Benz used same engine numbers M117.982 (D-Jetronic) and M117.985 (K-Jetronic) to deliver different engine versions for Europe / standard, the USA (emission regulated) and low compression (NV= niederverdichtet) markets with lower fuel quality both in 450SL and 450SLC as well as with other numbers in W108 280 SE(L) 4.5 and W116 450SE . But in reality these are very different engines that vary in compression, power, torque, cam shaft and emission control a lot.
The following table tries to give an overview over 450SL and 450SLC engines. 90% of all 450SL were built with US engines, so don't be surprised to normally find them in all the 450SL reimported to Europe from the US. The 450 engine at first was only available in the US while Europe got the smaller 350 engine with a similar power. Only as of 1973 MB delivered a more powerful European 450 engine. Unfortunately it is really difficult to identify which kind of engine is built into a car. Neither cam shafts nor the absence of exhaust return valve or the presence of European Jetronic and ignition components can make you really sure about the version as everything could have been swapped. There is a white paint labeling on cylinder heads back side, but you can harldy read it, even if engine is out of compartment. You can see that EUR labeling on pictures below,, USA is hard to read. In doubt only a compression test can give such a hint.
| Data | 350 SL 4.5 / 450 SL/C |
350 SL 4.5 / 450 SL/C |
450 SL/C | 450 SL/C | 450 SL/C | 450 SL/C | 450 SL/C | 450 SL/C | 450 SLC lightweight |
|---|---|---|---|---|---|---|---|---|---|
| Country | USA | USA | USA | USA | Standard | NV | Standard | NV | Experimental |
| Engine no. | M117.982 | M117.982 | M117.985 | M117.985 | M117.982 | M117.992 | M117.985 | M117.985 | M117.405-186 |
| Injection | D-Jetronic | D-Jetronic | K-Jetronic | K-Jetronic | D-Jetronic | D-Jetronic | K-Jetronic | K-Jetronic | K-Jetronic |
| Start of make | 1971-02-01 SLC 1972-06-26 |
1973-08-24 Calif. 1974-08-01 USA |
1975-09-01 Calif. 1975-11-21 USA |
Sep 79 | 1972-06-26 | 1972-06-26 | 1975-11-21 | 1975-11-21 | |
| Power DIN/SAE hp | 190 | 180 | 180 | 160 | 225 | 210 | 217 | 200 | 282 |
| at rev/min | 4750 | 4750 | 4750 | 4200 | 5000 | 4800 | 5000 | 4750 | 6000 |
| Compression ratio | 8 | 8 | 8 | 8 | 8,8 | 7,5 | 8,8 | 7,5 | |
| Max. torque Nm | 325 | 298 | 298 | 312 | 378 | 353 | 360 | 345 | 365 |
| at rev/min | 3000 | 3000 | 3000 | 2500 | 3000 | 3500 | 3250 | 3000 | 3000-4500 |
| Cam shaft no. left | 52 | 56 | 00 | 06 | 56 | 56 | 00 | 00 | |
| Cam shaft no. right | 53 | 57 | 01 | 07 | 57 | 57 | 01 | 01 | |
| Max speed km/h | 195 | 195 | 190 | 179 | 215 | 210 | 245 | ||
| Acceleration 0-100 km/h in s | 10,5 | 10,5 | 10,5 | 11,7 | 8,8 | 9,3 | |||
| Acceleration 0-100 mls/h in s | 29,5 | 29,5 | 29,5 | 35,0 | 22,6 | 14,0 | |||
| Differential ratio | 3,07 | 3,07 | 3,07 | 2,65 | 3,07 | 3,07 | 3,07 | 3,07 |
| MY 73 | 1972-06-26 | Introduction 450 SL/C in Europe and worldwide, earlier only USA |
| USA MY 74 | 1973-08-24 | California with exhaust return valve |
| USA MY 75 | 1974-08-01 | all USA with exhaust return valve |
| USA MY 76 | 1975-09-01 | K-Jet California |
| Worldwide | 1975-11-21 | K-Jet worldwide |
| USA MY80 | K-Jet 160 hp |
Compression ratio is done by different pistons. Main shaft is identical.
According to EPC cam shafts are changed more often than shown here.
Sources: Engelen, Wikipedia, EPC
Your Dr-DJet (Volker)
