Editing User:Eric/sandbox/Progressive Refinements (section)

=== 1950 ===
{| class="wikitable"
|+
!Date Introduced
!Chassis No.
!Unit No.
!Modification
|-
| Jan. 50
| 1-0 138 646
| 169 969
| <u>Oil filler and breather assy</u>
Now: with gasket
|-
| Jan. 50
| 1-0 138 765
| 170 086
| <u>[[Crankcase / Progressive Refinements|Crankcase]]</u>
Now: oil can be completely drained off (passage through timing gear chamber)<br>
Oil quantity: 2.5 litres<br>
Oil deflector no longer required. 4th main bearing bore provided with a groove
|-
| 17 Jan. 50
| 1-0 141 601
| 173 030
| <u>Oil dipstick</u>
Now: phosphatized and blackened
|-
| Jan. 50
| 1-0 140 243
| 
| <u>Cylinders</u>
Now: gasket between cylinder and cylinder head
|-
| 16 Jan. 50
| 1-0141 236
| 172 650
| <u>[[Exhaust Pipe / Progressive Refinements|Exhaust pipe]]</u>
Now: flanges surface-ground
|-
| 21 Jan. 50
| 1-0142 442
| 173 950
| <u>Induction Tube</u>
Now: welded seam between intake manifold and preheating pipe extended on both sides by 10mm
|-
| 23 Jan. 50
| 1-0142 587
| 174 106
| <u>Distributor Gear</u>
Now: with distance spring
|-
| Feb. 50
| 
|
| <u>Oil drain plug</u>
Now: with 19mm hex. head (in a number of cases)
|-
| 4 Feb. 50
| from&nbsp;1-0145&nbsp;121
up&nbsp;to&nbsp;1-0145&nbsp;450  
| from&nbsp;176&nbsp;911
up&nbsp;to&nbsp;177&nbsp;255  
| <u>Tapped insert for spark plugs</u>
Now: with hex head (345 engines)
|-
| 17 Feb. 50
| 1-0147 713
| rowspan=3 | <u>Engine No.</u><br>181 134<br><u>Fr. Axel No.</u><br>156 350<br><u>Transm. No.</u><br>159 350
| rowspan=3 | <u>Oil Drain Plug</u>
Now: with 19mm hex head (standard)
|-
| 22 Feb. 50
| 1-0148 529
|-
| 22 Feb. 50
| 1-0149 061
|-
| Mar. 50
|
|
| <u>Spark plug wrench</u>
Now: special "Hazet 5000" with holder
|-
| Mar. 50
|
|
| [[Fuel Pump / Progressive Refinements|Fuel Pump]]
Now: only black, flexible diaphragms fitted from now on.
|-
| 14 Mar. 50
| 1-0152 857
| 185 196
| <u>[[Pistons / Progressive Refinements|Pistons]]</u>
Now: only "KS" pistons with 0.035–0.055 mm clearance fitted from now on.
|-
| 30 Mar. 50
| 1-0 156 129
| 188 974
| <u>[[Exhaust Pipe / Progressive Refinements|Exhaust pipe]]</u>
Now: 32 mm dia.<br>
Formerly: 31 mm dia.
|-
| 3 Mar. 50
| 1-0 156 970
| 188 974
| <u>Intake manifold and preheating pipe</u>
Now: light metal jacket for intensified preheating of mixture.
|-
| 15 Apr. 50
| 1-0 159 092
| 192 300
| <u>[[Crankcase / Progressive Refinements|Crankcase]]</u>
Now: push rod tube eyes reinforced and lowered.<br>
Trapezoidal section gaskets fitted in a number of cases.
|-
| 25 Apr. 50
| 1-0 161 234
| 194 696
| <u>[[Carburetor / Progressive Refinements|Solex carburetor]]</u>
Now: hinged float<br>
Float weight: 12,5 g<br>
Pilot jet air bleed: 1.0 mm dia.
|-
| 2 May 50
| 1-0 162 580
| 196 110
| <u>Automatic cooling air regulation</u>
Formerly: throttle ring with swing handle
|- 
| 9 May 50
| 1-0 164 402
| 198 222
| <u>Muffler</u>
Now: connecting tube at muffler for intensified mixture preheating (through-flow systems) is standard.
|-
| 13 May 50
| 
| 199 321
| <u>[[Pistons / Progressive Refinements|Pistons]]</u>
Now: "Mahle Autothermik" pistons fitted in a number of cases.
|-
| 16 May 50
| 1-0 168 045
| from&nbsp;203&nbsp;404<br>up&nbsp;to&nbsp;209&nbsp;190
| <u>[[Clutch / Progressive Refinements|Clutch]]</u>
Now: inner springs no longer fitted in a number of cases.
|-
| 1 June 50
| 1-0 169 355
| 203 383
| <u>Exhaust valve</u>
Now: armoured valves in a number of cases
|-
| 2 June 50
| 1-0 169 704
| 204 025
| <u>Valve seat ring</u>
Now: made of V2A steel in a number of cases
|-
| 13 June 50
| 1-0 172 368
| 
| <u>Pully half</u>
Now: inner half with spot-welded spacer
|-
| 15 June 50
| 1-0 173 695
| 207 770
| <u>Main bearing No. I</u>
Now: with outside oil groove (bearing web in crankcase without oil groove)
|-
| 19 June 50
| 1-0 173 719
| 108 481
| <u>[[Clutch / Progressive Refinements|Clutch]]</u>
Now: one spring only (standard)
|-
| 29 June 50
| 1-0 176 547
| from&nbsp;212&nbsp;437<br>up&nbsp;to&nbsp;212&nbsp;947
| <u>Oil pump gear wheels</u>
Now: remelt alloy<br>
Formerly: steel
|-
| 5 July 50
| 1-0 177 736
| from&nbsp;213&nbsp;301<br>up&nbsp;to&nbsp;213&nbsp;455
| <u>[[Carburetor / Progressive Refinements|Careburetor]]</u> [sic]
Now: without hinged float in a number of cases
|-
| 6 July 50
| 1-0 173 141
| 207 431
| <u>[[Pistons / Progressive Refinements|Pistons]]</u>
Now: "Mahle-Autothermik" pistons in a number of cases
|-
| 1 Aug. 50
| 1-0 181 111
| 217 380
| <u>[[Push Rod Tubes / Progressive Refinements|Push rod tubes]]</u>
Now: trapezoidal section seal ring is standard
|-
|10 Aug. 50
|1-0 183 539
|220 317
|<u>Exhaust valves</u>
Now: armoured (standard)
|-
|19 Aug. 50
|1-0 186 361
|
|<u>Heating control mechanism</u>
Now: hex. head screw, 9mm Formerly: slotted screw
|-
|28 Aug.
|1-0 188 291
|from&nbsp;225&nbsp;484<br>up&nbsp;to&nbsp;226&nbsp;410
|<u>[[Pistons / Progressive Refinements|Pistons]]</u>
Now: "Nüral" pistons, 75mm dia. in a number of cases
|-
|Oct. 50
|1-0 285 789
|285 789
|<u>V-belts</u>
Now: installation of 875 cable-cord belts
|-
|Oct. 50
|
|
|<u>Oil filter</u>
Now: mechanical oil filter (service part)
|-
|23 Oct. 50
|1-0 203 845
|245 131
|<u>Valve spring</u>
Now: outer spring no longer fitted in a number of cases
|-
|16 Nov. 50
|1-0 210 317
|from&nbsp;252&nbsp;725<br>up&nbsp;to&nbsp;253&nbsp;775
|<u>Exhaust valves</u>
Now: with brazed tip
|-
|2 Dec. 50
|1-0 214 450
|258 311
|<u>Distributor pinon</u>
Now: distance spring no longer fitted
|-
|Dec. 50
|1-0 218 140
|263 133
|<u>[[Pistons / Progressive Refinements|Pistons]]</u>
Now: 20 000 "Nüral" pistons fitted
|}