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Prewar Workshop: Trembler coils

IMG 5457
Recently in the workshop I had ignition problems with a <1900 vehicle. The car would not really want to work well when cold and had problems finding the correct ignition timing.  The ignition system was a modern set of contact breakers and coils and seems to have been converted at some point in history from its unknown original battery operated ignition type.

In this case, I decided to use trembler coils for this car. The system best known from the Model T Ford. The main advantage of these is that they give a continuous spark as long as the contact is made. Unlike the contact breaker ignition, that charges the coil and releases the spark only once per powerstroke.

The way the trembler does this is that it has a coil inside that acts like an electromagnet. When the trembler is supplied with current, the primary coil charges and magnetizes an iron core its wound around. The magnet pulls open the trembler points that are mounted on top of the assembly.

The trembler points open, causing the current in the primary coil to stop and the magnet to be demagnetized. At the same time, the secondary winding has generated a high tension current which arcs over the spark plug. Demagnetizing the iron core in the primary winding closes the trembler points again and the process repeats. This process repeats multiple times per second which looks as a continuous spark as long as the assembly is supplied with power.

Power to the assembly comes from a distributor on the camshaft. This distributor has a brush that makes contact for a few degrees of rotation, giving the coil a spark for some length of piston travel.

I have included a few pictures of the trembler coil assembly, as mounted to the car. Also there is a video with how the spark looks on the coil, quite impressive!

Photo album can be viewed here: >click here<

For questions or remarks, please comment on the artice or ask me via This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Article by Jos van Genugten

Wednesday, 26 July 2017 Attention: open in a new window. Print E-mail

One car, 44 years, 250,000 miles…

One car, 44 years, 250,000 miles…

If you live in England then you will probably recognise the car in these photographs. This 1937 Frazer Nash-BMW 319/55 has been owned for the last 44 years by Mark Garfitt, who is certainly not afraid to use the car as its makers intended. In those 44 years Mark has competed in sprints, hill climbs, circuit races, trials, driving tests… driving to and from each and covering a huge amount of road miles in the process. In fact Mark has now covered about 250,000 miles (that’s more than 400,000km) in his car and shows no sign of slowing down. Pay a visit to any VSCC or BMW Historic club event anywhere in the country and, chances are, you will find Mark and his 319/55 there too.
Mark’s love affair with his German sporting car forms the basis for an article in the latest issue of The Automobile magazine, which is out now.
We know our PreWarCar readers are keen motorists – has anyone else travelled so far in their own prewar car? Let us know in the comments 

Photographs by Stefan Marjoram

Tuesday, 25 July 2017 Attention: open in a new window. Print E-mail

An unknown German aircooled car

unknown German aircooled car

An email from Christian Günzel came in. With attached this photo of a small but very crowdy 'family' car and he would like to know what it is. Quite often we receive this kind of photos, which we really enjoy. Sometimes they come with no information at all, but Christian gave us something we were a bit surprised of; the owner of the car. Namely, 'Emaillierwerke Vieweg & Förster, Penig, Saxony, Germany'. 
When we googled this name, we found a message that the company was founded on May 5th, 1903. This would mean the photo was taken after that date. But would the car be of 1903?
It looks like it is an air-cooled engine, and the license plate is visible. 
Christian thinks it is a Piccolo.
They made those little Voiturettes with air-cooled engines from 1904 until 1912. But we are not sure if they in the beginning already had a bonnet. 
Well, you know probably exactly what it is. Please, share your thoughts with us.

Enjoy your week.

If you have a good mystery photo, please send it in >click<

Monday, 24 July 2017 Attention: open in a new window. Print E-mail

The Launch and Decline of the V-8; part 1

The Launch and Decline of the V-8; part 1
In November 1904, the Marquis de Dion addressed a gathering of the  French motoring industry, held at the Automobile Club de France in Paris. He reflected on the contribution that France had made to the technical development of the motorised passenger vehicle, and the role of his own company in particular. As for the future, he was convinced that the future prosperity of the company lay in small vehicles and trucks. Given the evident success and prosperity that had been gained from producing small-engined vehicles, this approach was simply a matter of building on already strong foundations.  
By the end of 1905, however, this strategy was already unravelling, and in 1906 a range of motor buses was launched that rapidly became a familiar sight on the streets of Paris, London and New York. Twin cylinder car production came to a halt in 1908 (only to be re-kindled in 1911), the first V-8 engine was displayed at the Turin Motor Show in 1909, and by 1911 the bulk of the company’s production was four cylinder vehicles with various engine configurations: small cars had engines of 10/12hp; mid-sized cars were equipped with 14/18hp power units, and the top of the range vehicles had 25/30hp options, entirely adequate for formal Landaulet coachwork. The growth of the commercial vehicle business, for trucks and buses, for which the larger engines were necessary, was becoming very significant, and so the overall approach offered rather better economies of scale. There were other considerations too: by 1909 the huge number of competitors had ensured that margins on single and twin engined cars had been tightly squeezed. 
Robust though the strategy was around the manufacture of four cylinder engined vehicles, many manufacturers in Europe and North America were focused on achieving the optimum balance of power, smooth running and quietness from their engines, and in this respect four cylinder engines had their limitations. The development of a six-cylinder engine was an obvious next step.  Georgano reported that by 1908/9 some 62 makes of six cylinder cars were on sale in Great Britain, and a small number of French manufacturers including Darracq, Delaunay-Belleville and Renault had produced six cylinder engines, but difficulties persisted. Six cylinder cars had the theoretical advantage over their smaller relations of increased torque and the attractive necessity for fewer gear changes, but the longer crankshaft, of lighter construction to save weight, inevitably led to torsional vibration, with broken crankshafts and engine failure as the final outcome.
Quite apart from work on six-cylinder engines, there had also been development of eight-cylinder power units. The earliest development work on eight-cylinder engines had taken place in France as early as 1903 with the straight-eight of CGV and the V-8 designed by Clement Ader; the former never went into full production and the latter was created with the 1903 Paris-Madrid Race in mind, and was never offered for sale. Rolls-Royce made three ‘Legalimit’ V-8 cars in 1905, and in the same year Darracq produced a 22.5-litre V-8 that took the Land Speed Record at the end of the same year. The French Antoinette company designed a V-8 engine in 1906 that was declared suitable for airplanes or motorcars. 
De Dion Bouton had an interest in the V-8 engine, but it was not confined to motor car application.  In 1908 work also started on the design and development of aircraft engines, and there were distinct synergistic benefits to be had in the technical development and production of both.  The first indication that the company was seriously considering this particular opportunity was the patenting by De Dion Bouton in 1908 of the fork and blade arrangement of connecting rods, enabling the location of pairs of cylinders on the same vertical axis, which in turn required a shorter crankshaft and the potential for one camshaft. When combined with a twin throat carburettor, one throat for each range of cylinders, the end result was a power unit with effortless torque and smoothness, entirely suitable for the most substantial coachwork. 
Next week, we will publish part 2 of this article.

Michael Edwards is preparing a volume on De Dion Bouton motor cars from 1905 – 1914, and would welcome any information on the whereabouts of any examples of these elusive V-8 vehicles, as well as the larger engined, 25/30hp four-cylinder vehicles from the period.
If you have any information on these cars, please send us an email and we will forward it to Michael: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Special thanks to the De Dion Bouton club of the UK for their contribution in this research.
Sunday, 23 July 2017 Attention: open in a new window. Print E-mail

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