Mercedes-Benz W165 Grand Prix engine in 1:3 scale

[Vixen]

The 1939 Mercedes-Benz W165, 1.5 litre racing engine in 1/3 Scale  

                                                Index  

Part 1       A short history of the Mercedes-Benz W165, 1.5 litre racing car           Reply #1
Part 2       Producing drawings for the W165 Engine                                            Reply #11
Part 3       Supercharger Gearcase                                                                     Reply #27
Part 4       Supercharger Housing                                                                      Reply #33
Part 5       Roots Blowers, Synchronising gears and Rotor Lobes                           Reply #52
Part 6       Inlet Manifold                                                                                   Reply #58
Part 7       Transfer Manifold                                                                              Reply #70
Part 8       Superchargers Assembled                                                                 Reply #129
Part 9       Crankcase                                                                                        Reply #137
Part 10     Finishing the Crankcase: starting the Oil Pumps                                   Reply #191
Part 11     Cylinder Blocks                                                                                 Reply #209
Part 11B   The Water Jackets                                                                             Reply #216
Part 11C   Cylinder Heads                                                                                  Reply #220
Part 12     Overhead Cam Boxes                                                                         Reply #265
Part 13     Cam Shafts and Cam Drive Gears                                                        Reply #278
Part 14     Line Boring Main Bearing Journals                                                       Reply #294
Part 15     Dry Sump Cover (Oil Pan)                                                                   Reply #334
Part 16      Some more history of the W165 Grand Prix cars                                   Reply #364
Part 17      Oil Pipes                                                                                            Reply #375
Part 18      Cam Shaft Drive Train                                                                         Reply #396
Part 19      Magneto Drive                                                                                    Reply #454
Part 20      Cam Shaft Drive Housing                                                                    Reply #511
Part 22      Con-Rods                                                                                           Reply #642
Part 23      Crankshaft                                                                                         Reply #665
Part 24      Crankshaft and Camshaft Gear Train                                                     Reply #787
Part 25      Some details about my Schillings style built up Crankshaft                      Reply #805
Part 26     Soldering the Oil Pump Pipework                                                            Reply #817
Part 27     A little more history: the designer of the W165                                        Reply #832
Part 28     Gear drive to the Oil Pump Assembly                                                       Reply #854
Part 29     The Overhead Camshafts and Cams                                                         Reply #866
Part 30     Oil Pump pinons                                                                                     Reply #941
Part 31     Supercharger to Engine:  Inlet Manifold                                                   Reply #988
Part 32     Coolant Pump                                                                                        Reply #1026
Part 33     External Oil Scavenge Pump                                                                   Reply #1088
Part 34     High Pressure Fuel Pump                                                                        Reply #1119
Part 35     Pumps and External Pipework                                                                 Reply #1133
Part 36     Cam Box Covers                                                                                    Reply #1147
Part 37     Magneto's                                                                                             Reply #1181
Part 38     Coolant pipes and Crankcase vent pipes  3DP printed in plastic                  Reply #1219
Part 39     Flywheel and Clutch                                                                               Reply #1233
Part 40     Cylinder Liners and Cylinder Blocks                                                         Reply #1295
Part 41     Cylinder Lapping                                                                                    Reply #1307
Part 42     Pistons                                                                                                  Reply #1318
Part 43     Problems in the Combustion Chamber                                                      Reply #1346
Part 44     Making 64 Inlet and Exhaust valves                                                         Reply #1370
Part 45    3D printed metal parts for the coolant, crankcase vent and exhaust pipes    Reply #1401
Part 46    Cam Followers                                                                                        Reply #1421

Be patient; more to follow




Part 1       A short history of the Mercedes-Benz W165, 1.5 litre racing car       

Throughout the 1930’s, the German Mercedes Benz and Auto Union ‘Silver Arrows’ cars were an unbeatable force in Grand Prix racing.

The W165 racing car with it’s 1.5 litre V8 engine was developed by Mercedes-Benz for a single race – the 1939 Tripoli Grand Prix in Mellaha (Libya), then part of Italy. In those days the Tripoli Grand prix was a prestigious event in a prosperous Libya.

The Italian officials issued special regulations for the 1939 race in the Italian colony. The entrants were to be limited to the ‘voiturette formula’ for supercharged 1.5 litre engines. The intention was to sideline the German competitors, because both Mercedes-Benz (Tripoli winners in 1935, 1937 and 1938) and Auto Union (winners in 1936) had powerful 3.0 litre engines and thought not able to present a racing car for this class.

The managing director of Mercedes-Benz, Max Sailor, accepted the challenge and set the factory to work day and night to build two cars. The Untertürkheim plant was off limits to anyone without a special pass. They were left with the impossible task of developing cars in just eight months in time for the Tripoli Grand Prix. What emerged was the type W165, a scaled down version of their highly successful 3.0 litre Grand Prix cars.

In many design details, the W165 was based on the then current V12, 3-litre W154 Grand Prix car. The mechanically supercharged V8 had a displacement of 1,493 cc delivered 187 (254hp) at 8,000 rpm, and reached a top speed of 272km/h (160 mph) powered by a cocktail of alcohol, nitrobenzene, ether and acetone.

The development team under Rudolf Uhlenhaut achieved miracles. Two Mercedes-Benz W165 cars started the race in Tripoli on 7 May 1939, against an overwhelming number of competitors – 28 red-painted Alfa Romeo and Maserati voiturette racing cars. The W165’s achieved a triumphant double victory. Herman Lang won the spectacular, high speed, race for the third time, Rudolf Caracciola finished second, while the fastest Italian car with Emilio Villoresi at the wheel, crossed the finish line a good four minutes later.
 
It was to be their only victory, indeed their only race. Shortly after, war broke out in Europe, bringing motor racing to a halt for many years. Both cars survived the hostilities in neutral Switzerland and were eventually returned to MB. Motor racing would resume after the end of the war. Grand Prix racing was to run under the new Formula 1 regulations, which permitted either 1.5 litre supercharged or 4.5 litre un-supercharged engines.

After the war, a young British engineer, Cameron Earl, was sent to occupied Germany by the British Intelligence Objectives Sub committee (BIOS) to investigate and report on the development of Grand Prix racing cars before the war. The finished report, BIOS Report 1755, contained many detailed Mercedes-Benz blueprints of the W165 car and it’s 1.5 litre engine. The report was made available to the British motor industry and greatly influenced the design of the BRM V16, 1.5 litre, Grand Prix car.

I have obtained a copy of the British Intelligence report and have used the Mercedes-Benz blueprints as the basis of my CAD drawings for my 1:3 scale models of the W165 engine. Today, more than 85 years after it was designed, the W165 engine is still an exciting engine, a technical masterpiece.













That's my 1/3 scale Supercharger sitting on top of the real thing.

[Jo]

We are going to enjoy this 

Mike the forum software doesn't seem to like your first four photos I think it could be because they are BMPs 

Jo

[Jo]

Nice to see you in the photograph with the engine 

Jo

[Vixen]

The driver in the white helmet with the tartan band is non other than Sir Jackie Stuart. He was the guest driver for the only running W165 at last years Goodwood Festival of Speed. The only other surviving W165 is on permanent display in the MB museum in Stuttgart.

[fumopuc]

Hi Mike, thanks for reminding me of the history of this great race car. Waiting for the next steps of your build report.

[b.lindsey]

Looking forward to this one as well. Should be a great build log!!

Bill

[sco]

I too am looking forward to this build.

I have had the great privilege of sitting in the W165!

Simon.

[Vixen]

Simon, Do you happen to work for a certain car company in Northants?

[sco]

Yes - the last two years after the Festival of Speed they've brought the cars up to the factory and fired them up in the car park.

Chatting to one of the MB classic team they are now running the cars so much that their stock of original parts is getting depleted and they are having to remake some bits.  Apparently the desmodromic valves from the 300SLR proved quite a challenge for Mercedes HPP at Brixworth!

Simon.

[steamer]

I saw the germ of this project begin in ME a while back!   Welcome Mike

Looking forward to this build as well!


Dave

[Art K]

Mike,
I along with all the rest am looking forward to this build.
Art

[Vixen]

Part 2       Producing drawings for the W165 engine

The British Intelligence report was published and made public by HMSO in 1948 as a book aptly titled ‘Quick Silver’. Copies of this book are still readily available.



Cameron Earl, the report author, had free access to the Mercedes-Benz organisation in Stuttgart, located in the zone controlled by the Allies. The Auto Union facilities were in the Russian zone. Even by 1947 relations between east and west were deterioration, so access was denied.



Cameron Earl, a keen racing driver, made good use of his time in Germany, interviewing and collecting valuable documentation from MB and leading material suppliers. Earl was well aware of the proposed Formula 1 regulations for supercharged 1.5 litre engines. He therefore concentrated upon the Tripoli GP winning W165, and acquired many of the MB blueprints detailing the engine, transmission, steering, suspension and chassis. These prints were the obvious starting point for my project.

I am a lifelong user of AutoCAD. I only design and draw in 2D, because that it all I require to make engines. I discovered a way to import a scanned image as a bitmap (BMP) into AutoCAD. The BMP image is on it’s own layer and can be stretched to fit any desired scale. Just remember to freeze the layer when it is to the correct size.



The scanned images from Earl’s report were the best (and remain the only) information available. Using the AutoCAD drawing tools, it is then possible to painstakingly trace the outlines each component over the  BMP images. The process takes me months but results in a trustworthy overall assembly drawing with the interface between each component clearly defined.



The original BMP layer can be turned off and the relevant piece parts copied to separate manufacturing drawings for the individual component. I find this drawing work very enjoyable and a pleasant way to spend the long winter’s evenings when it is too cold to venture out into the machine shop.



My machine shop is almost entirely outfitted with CNC machines. My Emco Compact 5 CNC lathe and Emco F1 CNC mill were once the property of Her Majesty's Prison Service at Parkhurst Prison in the Isle of Wight, home to some very ‘tough nuts’. The machines were used in a vain attempt to retrain the criminals for a better future. Eventually, these old 1980’s technology machines were removed for disposal. I was the lucky guy who got to buy them. I stripped out and updated the ancient electronics and stepper motors with readily available modern stuff. I have used these old machines for over 15 years to produce a number of engines and other projects. It could be true what they say about the sweetest music coming from the oldest violins.

Every CNC machine needs a list of tool path commands to function. I use Desk NC to interpret G-Code instructions and move the tool around. I also use DesKAM to help create the toolpath commands in G-Code. I can export an outline shape from AutoCAD into DesKAM, I define the cutter size, depth of cut, step over dimension, feed and speed and the program works out the necessary toolpath. After that it is as simple as bolting down a block of stock material and pressing the ‘GO’ button.



Oh! I wish it were really that simple. Ha ha.

[Stuart]

Got a order in for extra pop corn for this build 

Looking forwards to what is to come


Stuart

[fumopuc]

Hi Mike, thanks for taking the time to explaine the details of the scource for your special design.

[DavidF]

Im scratching my head here trying to figure this one out.  Its a 1.5L V8??   Whats the bore and stroke of the engine, then what will the scale of the model be?  Looking forward to seeing your progress