6 quizzes on spark plugs for kart engines
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Under Review | KZ10C, THE TM ENGINE MULTIPLE WORLD TITLE HOLDER
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The new KZ10C has retained several features of the KZ10B that won the 2015 World title, but there are some key differences. According to the philosophy: stay with what works, but always work to improve
The KZ shifter class is the highest-performance category in international karting today and sort of the “elite class” of our sport. True, original go-karts were non-shifter vehicles and many think non-shifter karting should continue to be the point of entry into competitive racing.
This said, it’s beyond argument that KZ engines reach impressive performance levels with accelerations that, in the right gear and at maximum torque, literally nail the driver to the seat.
And while this is true of all KZ engines, the TM KZ10B by TM Racing that won the 2015 Le Mans World Championship with Dutch driver Jorrit Pex is considered the standard of reference.
Here is what has changed with the KZ10C: tilt angle of the crankcase and cylinder, which includes the reed valve pack; shape and structure of the cylinder head; transfer ducts; fuel intake chambers; reed valve pack attachment; clucth and exhaust cover.
A good way to do an in-depth analysis of these various innovations is to follow the flow of the fuel/air blend. Starting from the reed valve pack, we notice two additional screws that help keep all pack components together (conveyor, reed-bearing structure, gaskets) even when the pack is removed from the engine.
The angle that forms between the cylinder and the reed valve pack has been increased by 2 degrees 2 compared to the KZ10B, to improve the fuel blend flow from the carburetor to the cylinder ports " > The angle that forms between the cylinder and the reed valve pack has been increased by 2 degrees 2 compared to the KZ10B, to improve the fuel blend flow from the carburetor to the cylinder ports " > The crankcase’s front feet that rest on the engine plate are taller to allow for greater air flow and so an enhanced cooling effect " > The crankcase’s front feet that rest on the engine plate are taller to allow for greater air flow and so an enhanced cooling effect " > 0%
The fact that not much has changed in terms of technical regulations over the past few homologation sessions has helped the KZ class grow in numbers and prestige. And this helps explain why the newly homologated KZ by TM Racing, the TM KZ10C, represents an evolution of its world-winning predecessor, but not a total revolution. After all, there’s no point in quitting what works!
Moving on to the crankcase , there has been a visible increase in foot height to allow for Greater air flow to the front of the crankcase and, most importantly, to accomodate for the new carburetor position.
In fact, the angle between the cylinder and the reed pack has been increased by two degrees compared to the KZ10B, to optimize fuel bend flow from carb to cylinder. The path is now straighter and simpler and this helps the crankcase chamber fill up more effectively and improves overall efficiency.
Following the flow, we get to the crankshaft’s intake chambers, the cavities that fill with fuel blend and push it through the transfer ducts and into the combustion chamber. These too have been modified to make the engine more reactive on the low end.
The transfer ducts of the KZ10C are also shaped differently: lateral ducts come with a wider connector that creates a broader curve as it joins to the cylinder liner, while the main duct is smaller and shaped to yield more thrust at low and mid power ranges. The central duct (T) has a slightly wider corss-section.
Finished products in the TM Racing factory in Pesaro, Italy " > As you can see in this sequence of images, compared to the previous model, transfer ducts have changed in terms of cross section and shape to yield better low and mid torque " > As you can see in this sequence of images, compared to the previous model, transfer ducts have changed in terms of cross section and shape to yield better low and mid torque " > 
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