Ported cylinder heads by Dragon Motorbikes
Ported cylinder heads by Dragon Motorbikes

A ported cylinder head is one of those areas of engine building that, for most of us is shrouded in mystery.

Ported cylinder head ? We’ve all heard of the gurus who can take a mundane chunk of factory iron and make magic. We’ve also heard all the warnings about overly enthusiastic actually ruining a head’s flow. There’s truth on both sides here. What does it take to pull out some grinders and cutters and actually make a head better? Porting isn’t a pursuit that’s for everyone; it comes down to the left brain/right brain combination of a scientist’s mind and a sculptor’s touch. The science side is grounded in the physics of how air behaves, fundamentally based on fluid dynamics. Results are usually quantified through experimentation and flowbench testing. The sculptor’s touch is the inevitable boss in reality having to carve a passage by hand with a high-speed grinder.

Looking inside a ported cylinder head
Looking inside a ported cylinder head

80% of an engines power comes from its head…

Think about it………… the pistons move up and down but its the process of getting the air and petrol mixed and combustion completed that creates the drive, the force in pushing the piston down. The vast majority of customers completely over look the fact that a flowed head should form the centre of a well balanced tuning project. The valves open allowing air and petrol into the combustion chamber and then the exhaust valves open once the bang is completed allowing the process to start again. Improving this process WILL give more performance.

Anything we can do to your ported cylinder head to get the air moving faster with fewer restrictions with a greater volume will give more power and torque.

The inlet ports are opened but with keeping air speed high in mind. This increase in volume and air speed increases torque and power. The valves do not go un-touched however…they are the largest restriction in the whole induction process and are almost never touched. Making the valves LESS restrictive and able to flow more air and faster is where the real gains are to be had. Its possible to make standard valves flow as though they were larger valves…and why not…think about the financial savings (not having to purchase new valves and have the seats moved).

Ducati valves desmo at Dragon Motorbikes
Ducati valves desmo at Dragon Motorbikes

Its rare that a performance specialist actually flows its own heads…they are usually farmed out to engineering firms. We do them in house ourselves and this allows you the customer to get involved. We like you to see what we are doing and understand the process…you are our best advert. For our part we get to “taste” the results of our work on your ported cylinder head usually forms part of a package ( cams etc). Its great when the engine (now fitted with its ported head, re-profiled valves and matched manifolds) is started for the first time…and it has a much deeper exhaust note…its flowing more air…as expected. Test drive next and the fun begins. If this sounds like what you are looking for…great. If you need some answers to any question that you might have, alternatively feel free to call, we are only too happy to help

Ported Cylinder Head At Dragon Motorbikes Results
Ported Cylinder Head At Dragon Motorbikes Results