Lohen MINI W11 Supertech Performance Ported & Big Valve Head

Ported Heads

If you want to release the maximum horsepower from your MINI engine then a machined Performance Head is a must. On the standard MINI head the inlet ports are okay for the job and require just a basic clean up, but the exhaust ports are particularly poor and will be the main restriction in achieving maximum horsepower. Hence we have developed a performance head taking this into account.

We CNC machine precision cut all of the ported heads to ensure maximum accuracy and consistency on every port. Firstly we open the exhaust ports to allow more air to flow out and these can be matched to your exhaust manifold if you wish. The ports on the inlet side are pretty good so we simply tidy them up to get rid of any casting imperfections, the inlet manifold can also be matched to this.

A specially developed program then accurately machines valve seat/port throat joints to give a consistent smooth shape that aids airflow, both on the inlet and exhaust side. We then turn our attention to the combustion chambers, they are tidied up and any ‘high spots’ are removed, this reduces the chance of ‘glowing’ and helps to prevent detonation under a high state of tune.

We have found the following increases in flow with our ported head compared to the standard head. 

Flow Gains at ‘Xmm’ Valve Lift: 

8mm – Standard Camshaft
Inlet – 3.9% Exhaust – 27.0%

9mm – Performance Camshaft
Inlet – 6.3% Exhaust – 27.4%

Ported Heads with enlarged valves from Supertech

For those aiming to get the absolute maximum or simply want the best possible performance from their MINI, we would recommend increasing the valve sizes. This is where our ported heads with enlarged valves come in! These performance heads get the same attention as our ported heads (as described in the above section) plus we look after the valves and valve seats.

Once again addressing the exhaust side gives you the most benefits, we remove the standard valves (23.3mm) and replace them with larger Supertech valves (25.5mm) with single groove. New valve seats are cut and the ports are matched, as a nice little benefit, you will get a further 14% increase in airflow with a standard camshaft (compared to a ported head).

The inlet valves are once again from Supertech. Although the gains aren’t as dramatic as on the exhaust side, further improvements will be found when changing to a performance camshaft.We use 1.8 mm oversized single groove nitride coated inlet valves. 

We have found the following increases in flow with our ported head with enlarged valves compared to the standard head. 

We won't lie to you, we don’t spend all day in a workshop polishing the heads. Please don't be fooled into believing that 'hand mirror polishing' makes any difference to the flow of the ports. A good quality cutting tool should leave an almost perfect surface and require very little to no hand finishing work. Suitable for MINI One, Cooper, Cooper S, Cooper S JCW and GP.