Just had a look at those sites.

So, from what i can see, the Spi is a derivative of the CVH, and is still being used? The CVH was discontinued a while ago here. What is the bore and stroke compared to the 1.6? I wont use the 1.9 as it is simply longer stroke, and offers no more breathing potential - the factor that limits power on turbo'd engines.

Does a normal CVH head fit onto the spi?