D as an Irish, English, Dutch, German, Polish, Afro-Cuban, with bits of Spanish and Italian thrown in American I have a bit of an International flair.

OK the truth is I was raised on Japanese motorcycles and so I started with metric.

The A15 was 76.5mm and the A12 is 73.5mm. Both the damaged head and the spare GX head use 37/30mm valves. The trashed head had SI valves; they use a necked down stem (7mm) that flows more.

I now have an A12A block; in an effort to make use of the forged 76.5mm pistons from the blown A15 I've toyed with the idea of putting an A14 crank into the A12A. It's either that or sell of the forged Pistons for someone else to use for the same set up. I could also bore out the spare A15 block and fit the pistons in that.

The obvious solution would be 78mm or 79mm pistons and 38/33mm valves but I haven't worked out how I'm going to keep the compression down so I can use the readily available 100 octane fuel (I can get it 24-7) The larger bore means 12.5 to 13-1 compression and that mean using 105 octane fuel. Getting the 105 octane fuel means making a special trip to either pick up 5 gallon jugs or storing large quantities of the stuff at the house. I try to keep my racing as hassle free as possible.

I finish assembling the A12 today so in the next week the car should be running again albeit with 10-15 less horsepower.

I think we can officially say we've highjacked Vixen's original thread.