[Aberdeen Al]

I've had a look on Real OEM and from what I can gather the cylinder heads on all 1.6 Minis (One, Cooper & Cooper S) are all the same - it's just the cam that is different.

So as a double check can anyone confirm this?

Thanks,

Al

[cristo]

The part numbers for the cylinder head, cam, valve springs, etc. are identical between
the models, but the MCS uses different valves (althought the size is the same) than the MC and One.

[Aberdeen Al]

Quote: Originally Posted by cristo (original)

The part numbers for the cylinder head, cam, valve springs, etc. are identical between
the models, but the MCS uses different valves (althought the size is the same) than the MC and One.

Anyone know why the valves are different?

[k-huevo]

Forced induction creates extra heat on the exhaust side necessitating special heat tolerant alloys for exhaust valve material; the MCS’ exhaust valves are made from Inconel Inconel - Wikipedia, the free encyclopedia .

[minioneandrew]

I just bought a cooper s cylinder head to modify, why are the exhuast valves smaller than the intake valves? *walks off to get the dremel out*

[Aberdeen Al]

Quote: Originally Posted by minioneandrew (original)

I just bought a cooper s cylinder head to modify, why are the exhuast valves smaller than the intake valves? *walks off to get the dremel out*

According to the post above ^ the valves are the same size - it's only the materials that differ.

[minioneandrew]

Nope intake valves are definantly bigger than the exhaust 1's

[Aberdeen Al]

Quote: Originally Posted by minioneandrew (original)

Nope intake valves are definantly bigger than the exhaust 1's

I read the post as the valves were the same size - like for like - but that's just how I read it - I could be wrong but it just goes to show how things are interpreted eh?

[cristo]

Exhaust valves are typically smaller than intake valves. So to clarify things...
The Exhaust valves are the same size on the One/MC/MCS but different material on the MCS.
The Intake valves are the same size on the One/MC/MCS but different material on the MCS.

[k-huevo]

Just the exhaust valves are made of Inconel. The intake valves have a moment of fresh air to keep temps in check.

[chuntington101]

has anyone tried to go really made and race port the head?? how much bifferance did a FULLY work (ie you CANT take any more out! lol) make to performance/driveability??

thanks Chris.

[cristo]

Quote: Originally Posted by k-huevo (original)

Just the exhaust valves are made of Inconel. The intake valves have a moment of fresh air to keep temps in check.

But there's something different about the MCS intake valve.
Different part number for one thing.

MC exhaust valve 11347513024 / intake valve 11347513023.
MCS exhaust valve 11347513020 / intake valve 11347513019.

[MINIMANIAUK]

valve sizes differ ex/in because the engine sucks and expells at different efficiencies
"Race porting" removing material from the head to the max may not be the answer that you think it is - it is a bit more complex than that , the limit of the head is down to the intake valve size and that can only be increased by a small amount as the combustion chamber will be disturbed and a new gasket required and would be an expensive undertaking for little return.
there must also be a ratio retained between in/ex valves and this can be varied depending on the boost that you envisage running at .
gas speed and turbulence is also critical ,as is the thickness of material to water jackets.
the shaping of the ports and sizes also effect pressure drop across the head and gas speed as well as turbulence
porting heads is a very hard task and based on many years experience and highly labour intensive , flow benches only work to a degree as they are static values and engine running airflow behaves differently.
it is a cross between science and art . no machine can replicate the years of knowledge a porter has gained and they are reluctant to hand out the infomation they have and the things that work or dont
The ultimate head would be a totally new design and cost £10s of thousands in design cost alone

[chuntington101]

thanks MINIMANIAUK.

so taking what you have siad, and what happens with other makes, can you do say a +1mm inlet and exhaust valve? would this prudce much gain?? it has for other applications!

also i wonder if there would be a market for a PERFORMANCE head. one that you could design form scratch (much like they did with the A-series and the US v8 stuff) to get rid of the performance limiting factors that where built into the haed at design. this would let you run bigger cams, valves, ports, etc and still retian good strength to the head.

i know it could be exspencive. but when you look at other cars some class a head(s) as almost a 'bolt on' mod!

its a shame MINI didn't continue using this engine, then these kind of things might become more financially sound!

thanks Chris.

[MINIMANIAUK]

+1.5 mm is the maximum oversize and not easy or cheap to do with poor return on cost. +0.5/1mm is a good solution and works well -bigger is not always better! The standard head is very poor and gains are very hard to achieve using it -ported heads/valves are the way to go
A new head is an absolute non starter !!!! The MINI tuning market is simply too small and will still take a few years to develop at the moment with over 200000 cars in the UK ,I would not think that there are over 50 cars running a ported head let alone a different head!!!!!
That is depite there being the luxury of brand new heads available at silly low prices due to the JCW conversions.

[gecho4]

Does anyone know if the JCW head from the 2004 MINI Cooper (NON S) tuning kit is the same as the JCW Cooper S head? Or are they the same but only differ as the standard ones do (the exhaust valve material)? What about the gaskets?

On a side note does anyone know how to flatten the torque curve / improve the flat spot between 3000-4000rpm on a COOPER (NON S) with a JCW head.? People have also reported this flat spot with port and polished heads and JCW Cooper S heads. Can anything be done to improve this without negatively affecting anything else? Thanks in advance.