Project Evo IX Part 7: Cosworth Rocks!

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Project Evo IX Part 7: Cosworth Rocks!
Howard Watanabe of Technosquare uses this valve spring compressor to compress the valve spring with the head still on the engine.  The fulcrum is bolted to the head.

M2 cams have a reasonably aggessive but still quite streetable 272 degrees of duration and 11mm of lift.  With these specs and the MIVEC adjustable intake cam, the M2 cams have a broad powerband with good torque and good boost response.  With proper programming the M2’s have a rougher but still acceptable idle.

Project Evo IX Part 7: Cosworth Rocks!
The cylinder is pressurized with a leakdown tester to hold the valves closed while the spring keeper is pressed down with the tool.

Since we also wanted the ability to safely rev to 8000 rpm, we selected Cosworth’s high rpm single springs. The stock springs will safely work to around 7700 rpm with the M2 cams but we wanted to rev higher than that and have some safety headspace due to the engine’s rocker arm design.  Spitting rockers is not cool and usually highly damaging when it happens and therefore should be avoided at all costs.

Project Evo IX Part 7: Cosworth Rocks!
A punch is used to knock the retainer and loosen the keepers.  Then the keepers are removed with a pick and magnet.  Care is taken so the keepers are not dropped into the engine!  The springs are changed and the process is reversed.

When taking apart the stock valvetrain we noted that the stock camshafts had an unusual amount of wear considering the low miles of our engine and the fact that the rocker arms are equipped with rollers.  Because of this, we decided to WPC treat our camshafts.  WPC is the Japanese metal surface treatment which greatly improves wear and reduces friction of metal parts.

Project Evo IX Part 7: Cosworth Rocks!
Booya!  What a gain!  The Cosworth M2’s are the biggest gain  by far of any part we have evaluated so far.  Look at the broad powerband and the increase in area under the curve as well.

WPC works by bombarding the part with microscopic hard particles at very high velocities mixed with dry lubricants.  WPC improves the micrograin of the metal which helps with friction reduction, wear and fatigue strength.  Click here to read about the WPC process in detail. We also WPC treated our valve springs to improve their fatigue properties and to reduce their operating temperature.

Project Evo IX Part 7: Cosworth Rocks!
The huge Nisei Engineering Intercooler is much bigger than the no longer available XS Engineering part.

 

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