Having looked at the sections again I see what you mean, I'd forgotten about that. Does it depend on what head you have or is the basic design of the oval port the same. I don't actually know which one I have at this stage. WHile there are no oil leaks I'm a bit reluctant to pull it apart just yet but this will have to happen before I finalise the design. Measuring the H89 head section off the computer screen it is 14-15 degrees but there is no way to compensate for parallax.

Next time I have a spare day in Adlaide I'll have to drop you a line.

The design I'm thinking of did split half way through the bend, had orings there so it was a quick on off, great idea. I'm still thinking about the ideal place to do that, a necessity I think it the tappets ever need adjusting.

In any case it's fun creating different designs and then making stuff.

Thanks again.