There are two parallel worlds when we speak about the two-wheel environment: the 2-stroke and the 4-stroke worlds. Luckily, in our universe, Malossi cylinder kits exist for both.These are two different roads that we in Calderara di Reno have always pursued with the same objective: to squeeze the maximum potential out of every engine, keep it reliable long-term, while never sacrificing the fun.
Malossi was born right in the middle of the 2-stroke boom—an era where the sharp crack of an expansion chamber exhaust meant freedom. Because of that heritage, we’ve spent decades perfecting 2-stroke cylinder kits. Since then, every cylinder we design carries that experience, refined through years of track time, dyno testing, and countless miles on the road.
Malossi 2-stroke cylinder kits
Since we were talking about worlds and universes, let’s keep that metaphor going for a moment and consider together how one can intervene on a 2-stroke cylinder kit to improve its performance. There are two paths to follow: the first is to keep the displacement unaltered, and the second is to increase it.
Which path will you take?
1: boosting Your 50cc
Staying within a certain displacement limit – for example, the required 50cc in certain racing categories – doesn’t mean settling for modest performance. Quite the contrary. However, improving performance in these cases requires extremely high precision and painstaking attention to detail.
This is why:
- We produce Malossi 2-stroke cylinder kits by replacing cast iron with Nikasil-plated aluminium to reduce weight, improve heat dissipation), and increase stress resistance.
- We pay close attention to the transfer ports and the exhaust port: their number, shape, and angle are calibrated to the thousandth of a millimetre to allow the engine to breathe better.
- We optimise the compression ratio and the combustion chamber to turn every molecule of fuel into pure thrust.
- The piston is also lightened and balanced to move quickly and without causing any unnecessary vibrations.
This is how we manage to get the most out of a 50cc – without exceeding the displacement limit – and you can do it too with Malossi.
2: Why settle for 50cc?
When regulations or intended use allow it, we increase the cylinder bore up to the maximum safe limits. However, it’s not just a matter of numbers: an oversized cylinder must integrate well with the rest of the engine. For this reason, before designing a new Malossi 2-stroke cylinder kit, we verify the structural soundness of the engine: if it’s not stable, it’s not worth the risk.
Those who wish to increase their vehicle’s displacement face another fork in the road and must ask themselves whether a cast iron cylinder kit or an aluminum one is better. The answer depends on what you wish to achieve:
- A cast iron cylinder kit is perfect for those seeking a durable engine that is less sensitive to mistreatment and imperfect carburation, and requires only occasional maintenance.
- On the other hand, an aluminium cylinder kit with a Nikasil coating that protects and maximises the smoothness of the inner surface is the best choice for those seeking absolute performance and instant response (recommended for those competing in the Trofei Malossi (Malossi Trophy) races.
Once this decision is made, expansion chambers come into play, as they play a fundamental role in extracting exhaust gases. Without them, part of the fresh charge would be wasted. Therefore, in our factory, we study every fluid dynamic element – the angle of the transfer ports, the exhaust port, the timing diagrams – and we do this using advanced software that simulates behaviour and guides us towards developing even more efficient and reliable solutions.
We care deeply about this aspect and put so much effort into defining the volumes and angles of our expansion chambers that every Malossi exhaust is expressly dedicated to a specific cylinder kit. Why do we do this? It’s simple: our tests have confirmed that this specific combination guarantees the utmost performance.
2-Stroke cylinder kits: from the test bench to the tack
Imagine an engine as a patient on a surgeon’s table, and you’ll have a clear picture of how we work. Yes, we are creative, however, we are definitely light-years away from improvisation, as we base our work on results, numbers, and facts. Even though numbers don’t lie, we certainly don’t settle for them. Now, let’s get down to business: this is the moment when Malossi cylinder kits must pass checks on the test bench, road tests, and, equally important, track tests.
In this scenario, the Trofei Malossi (Malossi Trophy) races are a huge opportunity for us to test not just one, but approximately 30 identical vehicles, modified exclusively with our components, that compete during every single race. Same model, same preparation, same cylinder kit: if one wins, it’s thanks to the rider. This also proves to be the toughest test, one that allows us to guarantee that no part fails, that there are no unwelcome surprises, only reliable performance, even under extreme stress.
MHR cylinder kits: the 2-stroke racing department
Speaking of the Trofei Malossi (Malossi Trophy) races, we really must mention the MHR (Malossi Hyper Racing) 2-stroke cylinder kits, explicitly created for track experience and for the desire of those who demand the absolute maximum. These cylinder kits are characterised by:
- enlarged transfer ports for a more generous mixture flow.
- More aggressive timing diagrams.
- Ultra-thin rectangular single-ring pistons (0.8 mm) to reduce friction and improve response.
Over the years, we have evolved from 6 to 7 transfer ports for fluid dynamic reasons, featuring a split exhaust port with a central crossbar: this has become a Malossi MHR trademark feature. Clearly, this is a line dedicated to enthusiasts who are technically proficient in the field, and consequently, a reinforced crankshaft and connecting rod assembly is required to fully exploit this potential. The shaft, the connecting rod, and the bearings must withstand high loads and high RPMs, otherwise, the consequences could be disastrous or destructive for the entire engine.
Malossi 4-stroke cylinder kits
Our strategy for cylinder kits designed for 4-stroke engines is necessarily different. In these cases, we work directly on increasing the displacement, the compression ratio, and materials. Therefore, all our 4-stroke cylinders are made of Nikasil-plated aluminium: they are light, resistant, and capable of rapidly dissipating heat. Additionally, they feature super lightweight pistons that allow for quicker acceleration and lower inertia. As always, we strive to strike a balance between performance and reliability, because a 4-stroke engine must be long-lasting, as well as being powerful.
Why choose Malossi cylinder kits
Years ago, after days of work, you would jump on your bike and test it to see what you had achieved. At that point, fate could either make you happy or leave a bitter taste in your mouth, because in the best-case scenario, you might find you had moved forward, but in the worst, you might detect a drop in performance. At Malossi, that hasn’t been the case for many years now.
Our increasingly precise and sophisticated test benches, advanced software, and state-of-the-art technologies allow us to analyse, test, and correct everything necessary even before closing the engine. Our philosophy is always the same: observe, understand, listen to the engine, and improve. But that doesn’t mean “improve just for the sake of it” – rather, improve to surpass others, to do better than our own previous version, to be in pole position in terms of reliability, performance, and quality.
