If you’ve been to a karting race day, no doubt there are normal sights and sounds that stimulate the senses and which we’ve all become accustom to. The sights of karts throwing themselves into corners at considerable speed, brightly coloured fluro decals flashing past as spectators watching on in nervous excitement. In the pits, a hive of activity in amongst sea of trailers and gazebos, karts on trolleys being moved about this way and that, drivers scurrying around in their race gear preparing for the next heat or race, crews making setup adjustments and warming ups engines, or even just participants sitting around waiting for their next turn out on track. That is a pretty typical sight at most meets. There is also that typical smell of two stroke exhaust hanging in the air, and of course that familiar sound of two-stroke engines being revved to within an inch of its life that goes along with it. However, venture down to some clubs these days and the shrieking, soprano symphony of a field of two-strokes revving at 10,000rpm plus will be interrupted momentarily by the low, dull, droning thud of what could easily mistaken for as a ride-on mower convention.
As Dylan famously sang, the times they are a changing, and that is true also for kart sprint racing in Australia. Since the gradual phasing out of some of the most popular engines in karting, likes of which included the Yamaha KT100, there was a noticeable void left in its place for this more “affordable” tier of motorsport. This vacuum has seemingly, for the most part, been filled with the introduction of the four-stroke sprint class and continues to be a popular option for many drivers looking for a way to enter the sport, or even to just keep participating in karting given the continuously raising costs involved.
“A New Era for Club Racing in Australia”
Those readers from North America by now will be saying that fact four-stroke kart racing is nothing new and has been alive, well and hugely popular for years now. Even here in Australia, four-stroke kart racing is nothing new, with endurance karting typically running twin four-stroke engines. However, shorter, sprint style races (approx. 10 minutes from green light to chequered flag) with four-strokes is only a relatively new concept for Australian club racing.
The four-stroke sprint class (4SS) was introduced by Karting Australia in 2018 and offered by a number of clubs across the country. The aim of the class, as is strongly emphasised by Karting Australia, is to offer a lower cost alternative to those karting categories using two-stroke engines. With homologated, factory sealed engines and Vega VAH (hard compound) as the control tyres, not only is the intention is to keep cost as low as possible, but also to keep the class as mechanically simple, easy to run and uncomplicated as possible, making it a suitable option for beginner and recreational racers alike. Think of it almost as an ‘arrive and drive’ class of kart racing.
For a class to be “lower cost” the rules need to be tailored accordingly, enabling the use of engines which are indeed low cost to both operate and maintain. While you’ll get no argument from me that an air cooled, two-stroke power unit is still in essence a simple engine (if not the simplest interpretation of an internal combustion engine that there can be), the costs associated in maintaining such a motor to be at a competitive level in the sport can be somewhat exorbitant.
The next logical rung on the evolutionary ladder of simple engines therefore is an air cooled four-stroke. These too are relatively uncomplicated and are easily maintained – just change the oil in it occasionally and make sure the air filter’s clean. Hence the suitability for use in a class aimed at low cost and low maintenance racing. At the heart of the regulations, two engines have been approved and homologated for use in the 4SS class, those being the Torini Clubmaxx 210 (TC210) and the Briggs and Stratton LO206. For this post, I will be focusing on the Torini as that is what is in the title of the article, also this is the engine that I run on my own kart(s), however I would like to offer up comparisons between the two where possible.
Clubmaxx in a Nutshell
The Torini Clubmaxx TC210 is a single cylinder, four-stroke, air cooled go-kart race engine. With a displacement of 212cc and two valves actuated by means of push rods. Performance wise, it produces 10HP at 5,600RPM and 15NM at 3,400RPM, while an electronic ignition limits revs to a maximum of 6,100RPM. Starting the Clubmaxx is done by means of a simple pull starter cord, much the same as is on a lawn mower.
Taking into consideration the power output, the TC210 has similar performance to that of Yamaha’s KT100J, with the 100cc two-stroke pumping out around 10-12HP. This gives a good idea of what speeds and lap times can be expected from the more contemporary engine, While still not close to the performance figures of the more powerful KT100S (which is around 15HP, give or take), many karters will have started out racing with a J and still vouch for how fun the little junior engine can be. In a way, the Clubmaxx is the same. While nowhere near the most powerful or fastest things on track, it still can get a move on with the trick being to drive smooth and keep the momentum up.
A complete engine kit is available with almost everything needed to get going. The kit (TC210CEK) includes: The factory sealed 212cc race engine, air intake and filter, exhaust and a short length of fibreglass exhaust wrap, clutch, engine mount adaptor plate, chain guard, run in oil and race oil, a selection of carburettor jets and a “tool kit” which wouldn’t look out of place in an Ikea flat pack set.
The clutch included (and homologated by KA) is a Noram GEL19219 centrifugal clutch and comes with a 19T spur gear. The Noram is designed in such a way to allow adjustments to the setup, with three different shoe engagement settings (rapid, moderate and smooth) along with two different spring tensions for varying RPM engagement, red springs for engagement at 2200RPM and white springs for engagement at 2700RPM. While it doesn’t increase power in any way, it’s good to have this setup option available should there be a need to alter the way the power is delivered.
Torini engines are manufactured in Australia by Austech Industries, a subsidiary of Australian company, SP tools, and have been building small capacity, four-stroke engines of over 20 years. The Torini name is one that has been involved with motorsport for many years, more so in endurance karting. The introduction of the 4SS class across many Karting Australia affiliated clubs represented an opportunity for Austech Industries to broaden their participation in the sport.
Primarily, Austech have been manufacturing motors for use in the industrial sector, with applications such as powering generators. It should come as no surprise that when the foremost authority for karting in Australia (Karting Australia) began talks about the need for a simple and cheap four-stroke motor to power a new class of kart racing, Torini had the means to develop something that would suit the bill.
Basing its race engine on a motor already in production, design and main architecture of the Clubmaxx is actually based on that of the existing Torini TR210QE engine, an engine used for powering the SPGi3300E Inverter generator. Five years of research and develop was needed to turn the industrial generator motor into the Clubmaxx, with the final race ready and homologated engine being released in mid 2018.
Despite these origins as a stationary engine for a generator, only approximately 25% of the components are shared with motors from the industrial range. Components such as crankcase, head casting and a handful of ancillary items are common between the Clubmaxx and other Torini industrial motors. However, to meet the performance requirements of karting, the piston and conrod were heavily redesigned. Along with this, bespoke parts such as air intake and exhaust were designed and developed, all this adding up to give an increase in power output, 10HP (TR210) from the standard 7HP (TR210QE).
Engines are hand assembled at Austech Industries manufacturing facilities in Acacia Ridge, Brisbane, with individual parts and components for the motor being manufactured locally and overseas, mainly from China. At time of publication, 454 units have been built by Torini (source Austech Industries, April 2021) at their Queensland factory since its launch in 2018.
While the Clubmaxx is seemingly the preferred engine and currently dominates the manufactures battle of popularity amongst competitors, it’s by no means the only engine sanctioned for use in the class under the current Karting Australia rules. Briggs and Stratton’s LO206 (LO being an abbreviation for Local Option) is a competitive alternative to the Clubmaxx and is well within the regulations to be used for competition.
Like the Clubmaxx, LO206 is a 206cc, air cooled, four-stroke, single cylinder motor intended for use in kart racing, along with a few other feeder racing categories such as junior drag racing and micro stock cars. Originally coming about in 2008, the US built (hand built in Milwaukee, Wisconsin) LO206 has had a ten-year head start over its rival and has since then has proved to be a hugely popular karting engine for both sprint and endurance purposes. In North America, the engine has proven so popular that there is a bespoke Briggs and Stratton LO206 racing series that offers up close and exciting racing (if the videos from YouTube are anything to go by).
In much the same way as the Clubmaxx is based on an existing product from the manufacturer, the LO206 has its origins with the “Animal” range of single cylinder racing engines, sharing the same head, valves, cam shaft and short block. Despite there being a number of motor variations in the current range, only the LO206, specifically model number 206-124332, has been homologated by Karting Australia for approved use in the four-stroke sprint competition.
Clubmaxx Vs LO206 – On Paper
While the Briggs and Stratton is a comparable engine in terms of basic specs (LO206 is 206cc versus Clubmaxx is 212cc), on paper it doesn’t have the same performance figures as that of the Torini. While the difference in peak power is minimal between the two, the Briggs and Stratton lags behind with only 8.8HP compared to its rivals 10HP. This represents over a 10% power advantage in favour of the Torini. While we’re not talking huge numbers here, when racing in a class that is severely power limited, every horse counts. The reason for the power deficit could be due to any combination of factors, including the simple fact that it has a smaller displacement to that of its Australian counterpart.
All things being equal, the specs sheet would suggest the Torini would be the engine to bolt onto your chassis without any second thoughts, after all it is the more powerful of the two. However, these two motors are not equal in one critical area, and that is in price. The Torini’s extra performance comes at a cost, at the time of writing, a fully sealed Clubmaxx kit, with engine, clutch, exhaust, mount and oil are retailing at $1750AUD (price from Torini website, April 2020). Compare this with the Briggs, depending on the retailer, a LO206 will leave you out of pocket approx. $1500 for a sealed kit with similar componentry. Based on this, a Clubmaxx can cost around $250AUD more. While this doesn’t sound that much, especially given how expensive motorsport can be, in a racing category aimed at low-cost, entry level racing, this all adds up. Putting the monetary difference in tangible terms, the extra dollars to be forked out for a Clubmaxx equals a set of Vega VAH tyres, the control tyre for the class.
Clubmaxx Vs LO206 – On Track
This leaves a question still needing to be answered, does what the figures say on paper translate into a real-world performance difference? And does the extra cost of the Clubmaxx equal quicker times out on track? As the numbers would suggest an advantage in favour of the Torini, and therefore consistently quicker lap times.
The only way to truely compare is to have driven both engines back-to-back. For those who have had the chance and driven both engines in such a back-to-back comparisons (unfortunately I am not one of those people), the conclusion was as follows.
In the rubber-hitting-the-road real world, the two motors are closer that would be expected, in terms of their respective lap times. Some even going as far to describe that the performance is identical between the two. Richard Drooger (Grenfell Kart Club, New South Wales) is one of those who have had the means and opportunity for back-to-back running with both engines on the same chassis and tyres, and even going so far as to do the test on multiple tracks including Grenfell, Lincoln County International Raceway (Dubbo), Orange and Griffith karting tracks respectively. His feedback is that on medium to high-speed tracks both motors are more or less on equal terms. On low-speed circuits however, the Clubmaxx has the clear advantage “it (LO206) has a good mid and top end but crap bottom”, going on to say “At some circuits…they’re quite close but others there’s a fair performance gap.”
The feedback from on track experiences confirms what the data is telling us, the Torini has the advantage but only just. The closeness of their relative performance shouldn’t come as that much of a surprise, these two motors were selected to run in the same class for a reason, that being they would be similar in performance and be relatively level pegging with each other. Try as they might to have two similar power units that are as equal as possible, the Clubmaxx is more equal than the alternative.
If the performance gap between the Briggs and Torini is too close for comfort, have no fear because there is the ability to change the air/fuel ratio by altering the carburettor jets.
Jetting the Carburettor is the process of finding the correct air-to-fuel ration that the combustion chamber should be receiving. By swapping jets of varying sizes, either larger or smaller, it will alter the air-to-fuel ratio. As part of the complete engine kit from Torini (TC210CEK), there is a set of carburettor jets (pictured above) included for this purpose.
In theory there should be gains to be made from jetting the 19mm venturi carburettor. The factory default setup is rich, much too rich in fact, but this is a setup intended to protect the engine from running lean and causing possible damage. Jetting should unlock more performance out of the 212cc motor, putting even more of a performance wedge between itself and the Briggs and Stratton.
However, there does not seem to be a consensus on whether jetting is worth the effort. While I have not done any alterations to the jets on my carburettor, I have spoken with a number racers who have. The opinions range from one end of the spectrum, that being there is noticeable performance gains to be made; to the exact opposite end of the scale and that the gains are so small they can only be picked up with GPS lap timers or no gains at all and if it feels faster its simply the result of a placebo effect.
It is going to depend on the track conditions, weather, temperature, altitude etc as to whether jetting will actually have an effect on the engines performance and determine whether or not it is actually worth the effort.
While regulations for the class allow the use of either motor, it is obvious from the growing number of participants around the country that the Clubmaxx is hands down the preferred option, and will continue to be, the choice of power-plant for the class for the foreseeable future. As it has been homologated for atleast 6 years, expect to see them around your local track until at least 2024.
But why is it then the Torini so much more popular (in Australia) than the Briggs and Stratton, despite the price tag? Could it be there is more retail support for the Torini brand throughout the country? Could it be favourable to support locally manufactured engines over that from overseas? Could it be the simple fact the Clubmaxx is the more powerful engine, even while real world examples suggests both motors are almost par with each other?
In this authors opinion, I would suggest it is the later. Speaking from personal experience, when I was looking for an engine to run my kart(s) in the 4SS class I wanted to have the most power permissible under the rules for the class. 10HP versus 8.8HP is not much, but more is more, and in the world of karting every single HP makes a difference.
The Clubmaxx 210 continues to be a popular engine for this ‘new era’ of karting in Australia. Considering its crude origins, the Clubmaxx is proving itself as a reliable and dependable engine for the 4SS class of racing across Australia. It is one of the elements that enables those who may not have been in a position financially to finally be able take up the sport.