UK Monster Owners Club Forum - View Single Post - Ooooh, looks like it'll be piston rings then...

Kato · 27-09-2018, 01:27 PM

A brief history nickel silicon-carbide plating......Grabbed from the WWW

The 'Nikasil' surface treatment process was developed in the late '60s by Mahle, the German
piston manufacturer, in conjunction with NSU and Daimler-Benz (468) originally to provide a
wear resistant coating for Al-alloy rotor casings fitted to ****el rotary engines. It was the
result of a long programme of material combinations tried by many ****el licencees to
overcome a 'ripple' wear pattern characteristic of this engine type.

The process used electrolytic deposition to plate the Al-alloy casings with nickel in which
particles of silicon-carbide smaller than 1 micron (0.001mm) were dispersed. After finishing
treatment the plating was only 200 microns (0.2mm) thick in the ****el application (870).
Porsche first used 'Nikasil' coating in a normal piston engine for (air-cooled) Al-alloy
cylinders in the 1971 5L development of the F12 Type 912 unit and, compared with the
previous Cr-plated Al-alloy cylinders ('Chromal') found it increased power (302). The layer
may have been thinner than that used in the ****el engine (a 'few hundredths of a
millimetre' was quoted in (241) when applied in 1973 to the Porsche Type 911/83
competition engine (also air-cooled).

The reported improvement in oil consumption of the DFV with 'Nikasil'-treated Al-alloy
cylinders may have been a consequence of more rapid and complete bedding-in of the piston
rings, which is what is thought to have occurred in the Porsche 912 engine. If this then
reduced combustion gas blow-by a power gain would have been observed.

27-09-2018, 01:27 PM	#20
Kato Dismantled Join Date: Feb 2006 Location: East Molesey Bike: Multiple Monsters Posts: 2,223	A brief history nickel silicon-carbide plating......Grabbed from the WWW The 'Nikasil' surface treatment process was developed in the late '60s by Mahle, the German piston manufacturer, in conjunction with NSU and Daimler-Benz (468) originally to provide a wear resistant coating for Al-alloy rotor casings fitted to **el rotary engines. It was the result of a long programme of material combinations tried by many el licencees to overcome a 'ripple' wear pattern characteristic of this engine type. The process used electrolytic deposition to plate the Al-alloy casings with nickel in which particles of silicon-carbide smaller than 1 micron (0.001mm) were dispersed. After finishing treatment the plating was only 200 microns (0.2mm) thick in the el application (870). Porsche first used 'Nikasil' coating in a normal piston engine for (air-cooled) Al-alloy cylinders in the 1971 5L development of the F12 Type 912 unit and, compared with the previous Cr-plated Al-alloy cylinders ('Chromal') found it increased power (302). The layer may have been thinner than that used in the **el engine (a 'few hundredths of a millimetre' was quoted in (241) when applied in 1973 to the Porsche Type 911/83 competition engine (also air-cooled). The reported improvement in oil consumption of the DFV with 'Nikasil'-treated Al-alloy cylinders may have been a consequence of more rapid and complete bedding-in of the piston rings, which is what is thought to have occurred in the Porsche 912 engine. If this then reduced combustion gas blow-by a power gain would have been observed. __________________ "Political correctness is just intellectual colonialism and psychological fascism for the creation of thought crime"