Dynojet 250i Dyno Dynojet Model 250i


Suzuki GSXR inletSuzuki GSXR inlet


Superflow SF120 flowbench Superflow SF120 flowbench

Cylinder head work

In order to extract maximum performance from your engine, it is usually necessary to modify the cylinder head. Without doing this, you will never see big performance gains, regardless of what else you put into it.

Big camshafts may allow more air into the engine, but if the head is already causing a restriction then this is the first area that needs improving.
Standard factory produced cylinder heads are machined to a very basic specification and the tolerances are quite large. The image below shows a typical cylinder head.

You will notice that there is a rough cast finish to the ports and combustion chamber. There is also a very sharp ridge left from factory machining as indicated. These areas are extremely bad for airflow and to create the best inlet flow need to be smoothed out.

The image below is a combustion chamber and parts that are nearing finish. You will notice there is no sign of the ridge anymore. The casting marks have all been smoothed out also and the combustion chamber and exhaust ports will eventually be polished to prevent carbon buildup.

In the image right you will also notice the valve seats are now multi-angle. Standard factory production heads usually have anything from 1 to 3 different angles with the valve seat nearly always being at 45 degrees.

Our modification to seats is produced using a MIRA valve seat maching centre which can create any seat type from simple 3-angle to full radius. This improves airflow and also ensures that the valves are seated perfectly.
Most used heads will have worn, pitted and often poorly machined seats so this proceedure will create pefectly seated valves, far better than when they were fitted new. Remember, any leakage here will cost power!

When a customer asks for a gasflowed head, there are a couple of options available. As the image shows above, the head can be improved by cleaning up and matching areas in the ports, re-machining the valve seat area and also re-working the combustion chamber.
The other option available; which is also required for a great spread of power and bigger bhp numbers is to reshape the ports on many modern bike engines.
Even the latest cutting edge supersport bikes like Honda's CBR600RR and Yamaha's YZF-R6 suffer with poorly designed ports.

Correctly reshaped, these particular engines will show more than 10bhp peak gain, 10bhp mid and develop useable drive from around 3,000 rpm earlier than the stock factory produced ports.
The development work behind this was huge and the requirements to then create this by hand, means the cost for this work is at least double that of regular port work.

Below are a couple of reshaped inlet ports. Port reshaping is done using epoxy resin. The type used is designed and proven for this application, unlike other materials some of our lesser competitors may use.
We have epoxy filled cylinder heads still running after years without any problems at all.

On the left is a 2002 Yamaha R1 inlet port mold. The upper mold is the standard port and the lower is the modified one. You will see, it's clear a lot of work has been done in raising the port floor, reshaping the turn into the chamber and much more. On the right is a 2003 Honda CBR600RR port reshape. The upper is stock and the lower is an early stage development mold. Again, you can see that it looks completely different.

In addition to the above inlet port modifications, the exhaust ports are sometimes reshaped. This is done using a 300Amp Tig welder, which again adds considerably to the amount of work involved.

Unfortunately, due to the nature of our leading edge development work, we cannot show all our information. Therefore, some of the pictures were at very early development stages.
Hopefully what you have seen though will give you a good insight into our capabilities and state of the art tuning techiniques.

We are very serious about the amount of work that goes into our cylinder heads and are constantly developing heads on the flowbench, dyno and racetrack.
We don't just rely on dyno figures and graphs to show advancements, but have development bikes and riders testing all the time.
This means we don't rely on the results of any one means, but have the ability to combine data from all areas to helps us further what we can do.

Many people in the head porting business will run a sanding roll down the ports and use words like 'port and polish', then take your money. Others will drive up your compression and fit big cams and all you get is a good peak HP number with very poor midrange.
As you wil have seen, our work is far from this and second to none, with attention to detail and perfectionism borderline on madness.

If you have a look at our Dynogaphs section you will see our results, with many of these engines using standard parts which only goes to show just how important the flow of a cylinder head actually is!
Our Superflow Flowbench section shows further information on this.

Before work commences, all cyclinder heads are throughly checked so the customer can be advised of any forseable problems.
All work carried out is then matched to your budget, so prices can always be customised to suit.