Near the end of the 2006 season, we had to formulate a plan to discuss the next directions to go. It was either this, or drop the project. The following are Mike Norman's project notes that he shared with the rest of the Team for open discussion:
a. Through all of the previous generations of engines, we battled the inherent weakness of the Honda crankshaft design. These cranks were designed for production-based motorcycles with approximately 30 less horsepower than we have achieved so far (we have increased the output by 50% to date). Even with the modifications we have applied to the crankshaft, we still broke crankshafts. We decided that, in order to proceed with the project in the 450 stroker configuration, we needed a new crankshaft.
This decision, however, was proving very difficult. We contacted several popular American crankshaft makers, who all turned down the job for they said they could not cut the cam drive gear centered on the crankshaft. Finally, after reading in my favorite F-1 Engine magazine, I read about a new company in the USA, in California even. The company, SP Crankshaft (aka: Superior Crankshaft) http://www.spcrankshaft.com/homepage.htm was founded by Gerold Pankl of Pankl connecting rod fame, and Pete Spence, former president of Toyota Racing Development (TRD). I took a drive down to visit with the guys at SP. After much debate on scheduling and price, SP crankshaft said they could make us a crankshaft.
Looking at the problems we suffered with the modified-stock crankshaft, we all agreed that grinding, welding and re-heat treating of the stock base crankshaft was a bad thing. Again, we all agreed, a fresh start was in order. Starting with better material, and manufacturing the cranks to our specific specifications should reduce many of the inherent weaknesses right off the bat. In addition, this gives us the ability to incorporate many changes in the design of the crankshaft that will further reduce the weakness of the stock design.
We all feel very confidant we can produce a crankshaft that will live for an acceptable length of time (nothing’s forever, but we’d like to get close to that).
In addition to all of the redesigns and homogeneous materials, SP Crankshaft also finishes the crankshaft with a surface treatment known as Isotropic Super Finish process, developed by REM Chemicals http://www.remchem.com This process removes all surface imperfections reducing friction and improving lubrication properties, which means more horsepower and less wear.
With all of the benefits from having a new crankshaft made from billet like: higher rigidity, less flex, and less friction, I believe we could see more horsepower just from installing the new crankshaft.
2. Connectin Rods:
a. The connecting rods from Carrillo http://www.carrilloind.com/ , be it either of the two steel designs, or the Titanium design, have worked flawlessly for us. There are only a few drawbacks to the rods as they stand now. The “H-Beam” steel rods are slightly heavier than stock. Most of the weight is in the big-end though, as the small end is just around that of stock. Reducing reciprocating weight has always been my primary goal as this helps reduce the loads on the big-end of the rod, and limits friction due to extra loads.
The Ti rods are again phenomenal. They are light and strong, and have never given us a single problem. Carrillo has also said they believe they can reduce the weight even further as the first generation of rods were built with reliability in mind (they are very beefy). However, the biggest problem is the price. Due to all of the financial strains we have suffered so far, we will probably opt out of the TI for now.
a. The original pistons were adequate for us to get to the level we wanted. However, I believe we can do much better. Once we fixed the ring-land issue and attained the ring seal we desired, the pistons seemed to do their job. Looking at the wear on the skirts and sides above the top ring, though, I feel that the pistons are moving around too much (rocking, bending, over-expansion, etc.). So, we could definitely benefit from some changes there.
In addition, I have been looking at how to further reduce the reciprocating weight of components. Reading more and more about F-1 and IRL engine design, I have noticed everyone has gone to a two-ring design (one compression ring, one oil control ring-set). This makes for a more compact piston, which can reduce the weight of the piston even further. F-1 Engineers state that there is no additional oil consumption from a well designed two-ring piston. Also, most Engineers state that 40% of the friction from an engine is in the piston/rings. Two-ring pistons have less surface area, thus less friction.
Due to the troubles we had with the previous piston maker, I have researched and found that CP Pistons http://www.cppistons.com has come highly recommended by many highly-reputable engine builders, including SP Crankshaft. I have contacted them and have started to get some ideas of how to redesign our pistons. I will also make sure the new design has the flexibility for different bores (55mm, 56mm, 57mm and 59mm) and different wrist-pin locations for strokers or long-rod motors.
I have also been looking at different coatings to reduce friction and increase longevity of the pistons. There is a coating called Keronite http://www.keronite.com/motorcycle.asp that claims to increase heat barrier properties, reduce ring-land wear and help keep excellent ring seal. DLC coatings are also a possibility for the skirts and rings to reduce wear and friction for longevity and horsepower.
4. Porting, Valves, Valve Train:
a. The porting on all early generations of the NC-450V has been mild, to say the least. I hope to spend much more time with the heads on the flow bench, as well as work with some specialists in the area of Computational Fluid Dynamics (CFD) and other port & valve configurations. I believe there is at least 5% more power available from additional porting.
b. Again, as stated above, there is limited flowbench time in the current heads. In the Gen4 trials, I botched the ports by opening them up too much for the big valves. I believe if I get the velocity of the ports back up, the larger valve diameters should provide more flow and in turn more horsepower.
Once proven to work in regards to power, the option of Ti valves should provide less mass to control. This will in-turn require less spring force, even with modified cams, therefore reducing power losses from overcoming the valve springs. This will just further increase the benefits of larger valves, besides the improvements in flow.
c. The cams will prove to be a major task. The more I understand how a cam affects power, the more I feel I don’t know. In order to design a cam that works, many, many variables must be considered. The rate in which the cam opens the valves changes the way in which the spring has to control the valves from float and bounce. In order to achieve this, we have to look at designing the cam around valve springs that are available. Finding this information is very difficult. So, the research in the top end of the motor will take most of the time.
Once the correct package of ports, valves, cams and valve springs is found, I am certain that this will yield somewhere in the range of 5%~7% more power.
a. Once again, reading in my favorite F-1 Engine magazine, I am seeing that most teams in all forms of automotive and motorcycle racing are turning more and more to DLC, and other friction reducing coatings or processes. Items like valve train components, pistons, crankshafts (including bearings and rods), transmissions, and any other rotating or sliding components are being treated. The engineers are finding that they are not just seeing reductions in friction that produce more power, but are gaining reliability and power stability (dyno power is the same fresh vs. after 2 race weekends in an F-1 car). For our target hp, I believe that we will need to apply as many coatings in as many places as possible. In return, we should get much more enjoyment during each full season from these motors.
6. Engine Management Systems:
a. Externally, there are a few factors holding us back from achieving further advancement. Currently, we are limited to the 2-D advance curve of the HRC, or OEM Honda Ignitor boxes. Additionally, we are still trying to extract maximum power through the stock 32mm CV carburetors. We consider both of these areas serious limiting factors in developing these engines. So, we are looking into setting up an Engine Management System (EMS) to be able to take control of these limiting factors.
7. Exhaust Systems:
a. All of our motorcycles have been running on different exhaust systems. He have definitely seen that different systems can give considerably different results, which tells us that proper exhaust design will be critical for our power goals. Once we have dialed in the above listed parameters, we will look at designing an exhaust system that is directly suited to the entire package set forth in this plan. Again, we feel that this will net us a more responsive engine that will put the power out where & when we want it.