Cylinder Heads

19th April 2011

Finally, after many months of waiting, my cylinder heads have returned. Still waiting for the cam pullies to be machined up, but they're expected in a few weeks. In the meantime, here's a tour:

  

I think it's fair to say that the inlet valves are about as big as they can go...about 2mm oversized from standard. The exhausts are standard:

Ports have been cleaned up but nothing major done re-shaping wise, as they are already oversized. Inlets:

  

...and exhausts:

Then we have the new cams - as I mentioned before, these are Cat Cams 1030911. 20% more lift at 11.15mm, and 20 degrees more duration, than stock. In comparison, the sportier Alfa GTA versions came with 9.7mm of lift, a mere 7.5% increase over the standard tune.

Here's a comparison of the old and new. The difference is quite clear to the eye, the new lobe is taller and fatter:

  

The only downer is that I will have no idea what difference this will all make for about another year!