In addition to the Cryo & REM processes, I also wanted to reduce friction further, and increase the longevity of the parts as much as possible. Since the OEM Honda parts are getting harder and harder to get, and the custom made parts are expensive and not feasible to keep replacing, I researched many coatings available. A company was brought to my attention by another avid engine enthusiast. So, I contacted them to discuss the options they had available for our engines.
They do a variety of Metallurgical Coatings that could be applicable to performance engines. With their guidance, we decided on WS2 (Tungsten Disulfide) for the bearing surfaces, TiN (Titanium Nitride) for the piston rings and Titanium Spring Retainers and CrN (Cromium Nitride) for the valves.
The engine bearings are getting harder and harder to get lately. So, reducing the wear on them was my primary concern. The REM process to the crankshaft journals helped reduce the friction as much as possible on the crankshaft. However, application of the super-slippery WS2 (Tungsten Disulfide) helps reduce the friction in the event of a loss or reduction in oil film. The film is applied dry and is said to be "one of the most slippery materials in the world" by many. That sounds like something I want on my engine bearings in the event of oil cavitation or starvation.
The engine bearings are not all that benefit from the WS2 coating. We will also apply this coating to all items that have rotating or sliding friction like gears, shafts and rotors during the next teardown. This is very similar to the Gen5.2 EFI engine that we tried the "Micro Blue" coatings on. WS2 is very similar to this coating (maybe identical) but my interaction with Brycoat leaves me more confident in their work.
The next items that seem to wear quickly on our engine are the piston rings. With the heat and pressure that we have been creating from the horsepower gains, the rings seem to lose their tension and wear the faces a bit faster than we would like to see. TiN (Titanium Nitride) is a Surface Coating process that applies a strong ceramic compound that improves the surface hardness of the material it is applied to. In our case, we had the TiN applied to the face of the rings. We are expecting to increase the time between ring change intervals, hopefully an entire season of racing before needing replacement. In addition to increasing longevity, they TiN is also supposed tgo decrease friction, prevent bonding between the rings and the cylinder wall (microwelding) under extreme heat/pressure conditions and....the gold color just looks good.
The Titanium Valve Spring Retainers have also shown signs of premature wear in the past. To prevent this, we also had the TiN applied to the Retainers. We have used this previoulsy with excellent results (no visible wear after several seasons of racing).
The OEM Honda engine valves are pretty incredible when it comes to wear. Unfortunately, I haven't seen any of the aftermarket options wear as well as the OEM parts. The Stainless valves that I have used in the past would still wear out at a rate that was unacceptable to me. So, in an attempt to increase this time, weapplied CrN (Chromium Nitirde) to our Stainless valves. CrN, like TiN, hardens the surface of the parts, as well as reduces the friction and wear at the valve stems and prevents microwelding between the valve faces and the valve seats.
We just received the first batch of parts back this week. We will be doing post-season rebuilds shortly and will post the before/after dyno results. We will also show mid-season and post-season wear progression results over time. Please keep checking back from time to time.
Sadly, the application of WS2 caused many engines to fail due to improper bearing preparation and application. So, we won't be using that process again :-(