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Small history of the (racing) piston



These 12 pictures show almost 100 years in the history of the racing piston, they also show an amazing similarity to one another. This is because even the first one was a milestone in the history of motor-racing. You can read more about this gigantic engine here.

The holed pistons actually represent weight saving, something that certainly cannot be said for Blitzen-Benz engine. If you look closer, you'll see that there are no oil scraper rings, which indicates that the oil consumption was considered secondary. The first Blitzen-Benz also had dip lubrication. So, what we're dealing with here, is more a vehicle for achieving speed-records, not suitable for longer distance racing.


Whereas the first, was still a cast-iron piston, the next were already forged and were made from an alumunum alloy. Here the oil was properly scraped off and the shape of the piston crown pointed to two standing valves at an angle to each other and a high compression. This was possible because of the particularly anti-knocking alcohol mixture which was used at that time. Two valves were sufficient for the engine constructors of the Mercedes W25, because it was fitted with a compressor anyway.


The here chosen perspective is a little deceptive, because the Auto Union Type C was in direct competition with the Silver Arrows, only it's pistons had a 3 millimetres smaller diameter, indeed, it needed 16 of them instead of 8. In the years up to 1938, both engines were further developed to the point where, with a full-fairing, speeds of way over 400 km/h were possible on closed sections of the motorway.


One could be of the opinion, that in the post-war era there were no big differences. Mercedes was still building straight eight-cylinders, indeed, this time with far less cubic capacity and due to the lack of charging, much higher RPM. In the Mercedes W196, more than 8.000 RPM were possible.


We've now arrived at the Formula-1, right in the middle of the Cosworth-era. This company was doing special research in the field of valve arrangement and worked with a somewhat smaller angle between the now, four valves. Their engine would be used, mostly by several teams at the same time, for nearly 15 years.


Erich Zakowski was very successful in the German motor racing championships with the Ford Escort and the Capri. He was considered to be one of the early specialists in the field of charged petrol engines. Indeed, the development-contract for the Formula-1 went to Cosworth. Zakowski decided to take part as an independant team, and to develop both the chassis and the engine. In 1990, after just under five fruitless years, he threw in the towel.


The engine had a capacity of 1.495 cm³ and produced 700 Nm of torque at 8500 RPM, although during qualifying it worked with a charging pressure of 4,5 bar. Under these circumstances it probably even achieved more than 735 kW (1000 HP) at 11.000 RPM. The con-rods were made of titanium, the timing control was done by Bosch-Motronic and the lubrication was dry-sump.


The enormous amount of weight-saving, can clearly be seen in the previous two- and in the following pistons. Only a small piece of the piston skirt is left to do the guiding. Nonetheless, the pistons must be able to take a lot more punishment because of the return of the turbo-charging, they are however, looking at the capacity, very much smaller. The heat dissipation is done by injecting oil from below, into the cooling channel of the piston.



Then the cubic capacities, together with the number of cylinders and also the RPM, started increasing. Something new, were the 3 intake- and 2 exhaust valves, which were partly taken from standard engines, in the end however, they weren't successful. After a while, they were dropped, also in the Formula-1. Because more than twelve cylinders never made any sense, and the capacity could not be increased, higher RPM were continually used.




3 litres V10


A ten-cylinder engine with cylinder-banks at a angle of 80°. Its valves are pneumatically controlled. Both the ignition and the injection are electronically controlled. The engine is equipped with Lambda-regulation.


In the end, by making the bore twice as large as the stroke, an average piston speed of less than 25 meters/sec. was achieved. The RPM increased up to 19.000 revs. The last piston shown originates from the V8-era, in which there was a capacity limitation of 2,4 litres, which caused a decline in performance. The piston now consists practically of a disc with piston rings which is mounted at the top of the con-rod. 03/15








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