Compression data needed

[Ron]

Can anyone supply a bit of info re data to work out compresion ratio. I have cc'ed an early G161 head at 48cc, compressed head gasket is 1.5mm thick, bore is 83 mm (1 mm oversize, and the pistons are flat top with deck height 0.2 mm below the block. This barely makes 8 to 1, hence domed pistons are needed ..... worried about the valve clearance with these raised pistons though.

What I want to know is the volume taken up by the raised part of a stock "domed" piston., Has anyone actually measured the volume of the dome. I estimate it is worth 5 cc.

I picked a Crow Cam from the factory, it is their 2000-6000 cam with .4255 inch lift, cost $230 total. Also you might like to know that Lukey (now Walker) make an interference system for a Gem and it cost me $104 direct from the supplier, The best price for a similar (virtually identical) Pacemaker system is $200. Both systems are not all that flash because the primary pipe lengths are all different. Does anyone know who makes an interference system with 15 inch primaries (all 1.5" pipes the same), and about 19 inch for the first collector and secondary 1.625" pipes?? I couldn't find a decent extractor system so had to compromise.