I was talking to BW (Paul Henshaw) recently and he did mention that he ran out of those CDI boxes but according to him Hitchcock's performance TCI is pretty much based on his Ignition unit. So it looks like AVL'ers can use them too.
Tom - About the compression part - I thought the 535 piston alone would bump the compression by loads right? In that case there isn't any way to get the squish band corrected ? or there is a way to do it?
Regards,
Sanket
Sanket,
The extra displacement will increase the compression some, all by itself. But the piston is a flat top, and I don't have the data on how much compression that will add.
Regarding the squish, it needs to be within less than .060" from the head, and no closer than .020" from the head at TDC . This can be achieved by setting the deck height of the barrel by machining the barrel down so that the piston comes all the way to the top, and then the thickness of the gasket will typically be enough to set the squish gap.
However, there needs to be enough room for the valves, so that they don't hit the piston at TDC, so that clearance would need to be checked. And bringing the piston up that high might cause compression to be too much. That would require some higher octane fuel, or some piston or chamber relieving to work with the available fuel octane. Squish can help to use higher compression, but it's not a miracle. It has limits too. I think you found out that 175 psi is about the limit for your AVL, didn't you?