Top oil
Top oil was a special lubricating oil that was added to the fuel of four-stroke engines in order to improve the lubrication - especially of the valves - in a ratio of 0.2 to 0.3% by volume. "A positive effect was not detectable," however, "increased oil carbon deposits" were found when using top oil. The top oil consisted essentially of bright stock .
History and technology
As early as the 1930s, a small amount (1:40) of oil was added to the fuel in four-stroke engines in order to improve lubrication under particular loads. The top oil, which only reaches the piston and valve stems in very small quantities, must have exceptionally good lubricating properties. On the other hand, when it arrives in the combustion chamber, it should burn down completely without leaving any deposits or coking, and in the outlet it should still form enough turbulence in the oil mist to ensure that the outlet valve is also lubricated. With the appearance of synthetic oil in the 1970s, top oil disappeared from the market.
Use as a miracle cure
In its time, top oil was considered unequaled in terms of lubricity and was therefore used instead of normal engine oil, also for psychological reasons, in order to "give the driver a feeling of better lubrication security". Top oil was also used for a long time as an alleged miracle cure to burn coked valve disks. Today, additives are added to gasoline that serve this purpose much more efficiently. There are specialized additives for cleaning the valves for classic cars .
When top oil is added to the fuel, regardless of the type of valve control , not only the valves but also the pistons, cylinder liners and, in newer engines, the injection nozzles are lubricated. This is not only completely unnecessary for mechanically intact engines, but can also make them ineffective via the oil residues in engines with vehicle catalytic converters .
Individual evidence
- ^ Obenöl in the Oldtimer Dictionary
- ^ Kurt Mair: The motorcycle: technology - care - repairs. Heel Verlag, reprint of the 2nd edition 1937, ISBN 978-386852-307-2 , p. 390. There it says: "This oil additive can be advantageous in the case of special stresses, although it should generally be avoided due to the strong residue formation Incidentally, special oils have recently come onto the market which are only intended for admixture with fuel, save the amount of lubricating oil and, in particular, are intended to remove the oil residues that have accumulated in the explosion chamber. Experience with such admixtures has been good ".
- ↑ Properties (.pdf)
- ↑ Willi Thoelz: Motorrad und Motorroller Altes Wissen 1957. Verlag Kleine Vennekate, 2013. Reprint of the 4th edition from 1957. ISBN 978-3935517669 , p. 172.
- ↑ aral.de Additive (accessed on October 27, 2015).
- ↑ User tips, BACTOFIN, BALLISTOL and others .
- ↑ Obenöl , manufacturer information (.pdf) ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. .
