|
Coatings
We're looking to the Nascar, Formula, and Winston Cup circuits for the latest innovations in coating technology, from friction reducing to secondary lubrication coatings. In this round of R&D, all three engine build-ups, from the squishies to roller to even our 3.0 liter will receive a heavy dose of coatings on all kinds of surfaces from the lifters to bearings. Of particular interest to us is this DLC, or better known as "diamond like carbon" coating that can be applied to an infinite number of surfaces, from cam and lifters, valves, and even bearings. But most importantly, we're looking at what the DLC coating can do for us when it comes to lifters. Considering that we're going head on into lifter testing, trying to find the perfect lifter, DLC coatings give us another option. Using lifters that have shown themselves to be problematic, we have cyrogenically treated and/or SLR'ed some of the lifters, in addition to having a portion DLC coated. We'll be able to observe side by side how the same lifter processed a few different ways performs.
The
primary benefits of a DLC coating include:
Where most individuals are familiar with the
graphite coated skirts of a mahle piston, the coatings we're using on
our pistons are decades more advanced than what has previously been
applied to an aircooled engine. Piston tops, skirts, and ring lands all
receive their own specific coating, each with the goal of increased
efficiency, reduced temps, and reduced wear. The thermal barrier coating used on this piston top is an excellent ceramic, high temperature heat management coating. It contains heat to the combustion chamber. This same coating is used on exhaust ports and on the combustion chamber as well as the faces of the valves to keep heat out of the heads and in the combustion and then the exhaust. Although questionable whether or not this coating will actually help produce more power, it does allow for safer margin of error.
Note that the intake ports on the Type 4 are not
coated, as we are doing side by side testing with carburetors and fuel
injection, and although teflon based coatings for the intake to reduce
drag and increase port velocity work fine for fuel injection, they wreak
havoc on carbureted engines. The coating applied to the skirts is a dry film lubricant that retains oil while reducing friction and heat. This coating will allow for the use of reduced clearances without scuffing. The results are less blow-by, and increased horsepower, and less wear on the cylinder walls and piston rings. The dry film lubricant provides invaluable secondary lubrication that greatly extends piston life and provides superior corrosion resistance. walls and piston rings. Similarly, the ring lands receive a third special coating that promotes healthy rotation for even and reduced accumulation of wear. Also, coating the ring lands also helps to prevent "micro-welding" of the ring lands in some cases. On any bearing surface, we applied a secondary lubricant coating similar to that which is found on the piston skirts. This coating is proven to dramatically reduce catastrophic engine failures in cases where engines incorrectly plumbed or suffering from low or no oil pressure, cold starts, low or no flow have survived with little or no significant damage. Engines with excessive oil temperatures to the point of oil “breakdown” have avoided total destruction of expensive components due to the secondary lubrication provided by the .0002 to .0004 inch layer of dry film lubricant. Dry film lubricants reduce catastrophic engine failures and last longer than uncoated bearings. Coated engine bearings last longer than uncoated bearings. In other applications, we've witnessed Winston Cup bearings with as much as 2000 race miles with RPMs exceeding 8000 and show relatively no wear. Short track engines that have been used for two or three seasons of weekly racing appear to still be serviceable. Bearings from drag racers that have been used for five seasons with an untold number of passes are also serviceable. Overall, coated engine bearings have proven to successfully save time and money for all racers using the coating. With minimal investment, these coatings provide a wider margin of safety to rely on and when applied to street cars, even further the reliability and longevity we seek with all our engines. From Top to Bottom:
Although we're working with a whole slew of coatings, we're not even scratching the surface with our thermal dispersant, thermal barrier, and dry film coatings. In future R&D projects, we'll be investigating the performance gains from oil shedding windage coatings that can be applied to surfaces such as rods and crankshaft counterweights. DLC coatings have been used on floating wrist pins to eliminate wear and friction and most importantly, DLC coatings have made titanium valves streetable, as race engines with thousands of miles and hundreds of hours of track time show NO WEAR, when it is common for titanium valves to have life spans measured in hours. Furthermore, these coatings can be applied in a wide array of automotive applications from oil pumps, to reduce drag and friction, to transmission components, to maximize power transmitted to the road. We feel specialty coatings are the future for aircooled precision performance and key to longevity and reliability exceeded that of modern production vehicles. Jake Raby Copyright 1997-2008 Raby’s Aircooled Technology. |
