Summary for crankshaft coating for roller bearings Discussion
Crankshaft coating for roller bearings is discussed as a way to let needle rollers run directly on an EN40B crankshaft in a high-output Mini Cooper S engine. Ben asks whether cryo tempering, triple nitriding, or some other coating would make the crank surface durable enough for roller mains and conrods. Marie S. replies that her company regularly treats EN40B racing crankshafts with pulsed plasma nitriding, which gives a case depth of about 0.3 to 0.4. Ben then asks whether that is deeper than triple nitriding and whether it is an exotic process available in Australia. Later, Jose Macias offers a different view, saying the way to go for split roller bearings is carbon nitride and that their roller crankshaft system works well. The thread does not settle on one universally accepted answer, but it points to nitriding-based surface treatments rather than cryo alone.
Q. Hello,
I race a mini Cooper “s” in Australia and I am at the end of the road in terms of technical development towards hp/reliability in the old a series engine. Like any one that races I am always looking at going faster and being more reliable. We have been able to achieve 153.3 flywheel horsepower out of a controlled original head and ideal compression/stroke/squish formula. I am very excited about my idea to rollerize the crank main and conrod bearings. I have been able to attain the roller bearings of low enough profile and speed and load rating however because of this low profile I need to run the needle rollers directly on the crankshaft. I have had people tell me that cryo tempering and then triple nitriding will make this suitable. Does anyone know of a coating that would be resilient enough onto en40b crankshaft material.
Thanks.
Ben T [surname deleted for privacy by Editor]
hobbyist – Sydney, NSW, Australia
2004
A. Hello Ben,
I work for a surface engineering company and we regularly treat en40b crankshafts used in racing cars. The treatment we apply is plasma nitriding (pulsed). This gives to the cranks a case depth of 0.3 to 0.4.
Cheers,
Marie S [surname deleted for privacy by Editor]
– Farnborough, UK
A. Thanks Marie, it sounds like the process I am after my heat treatment guy recommends to triple nitride. Will the plasma nitride give me deeper case than this? Is the plasma nitride an exotic treatment or should I be able to get it done over here.
Benjamin T [surname deleted for privacy by Editor]
– Sydney, NSW, Australia
2004
A. The way to go with split roller bearing for crankshaft and con-rods is carbon nitride, we just test our roller crankshaft system and work perfect.
Jose Macias
automotive engineering – Edinburg, Texas. USA
April 7, 2008