Check my CR sum assumptions
Discussion
Derek, you can measure the actual piston to head clearance with a feeler guage whilst the heads are installed. Piston to deck volume can be done by measuring down with a depth guage, dial guage or vernier. Piston bowl volume and head chamber volume you measure using a section of plastic like Brummie did. A cd case is good for this. Volumes can be determined using a large syringe or calibrated burettes etc. Then you can 'stack up' the maths. Your dynamic CR is more important then your calculated CR and the cam has a big effect on that. Dynamic is always lower the static.
If your engine could be set so the deck height was horizontal you could put some grease on the cylinder walls with the piston at tdc. This will seal the rings and you could measure the volume in there with oil delivered in measure volumes.
If your engine could be set so the deck height was horizontal you could put some grease on the cylinder walls with the piston at tdc. This will seal the rings and you could measure the volume in there with oil delivered in measure volumes.
Brummmie said:
Richard 858 said:
94.45 hp/litre here.
Would want triple figures with FI! 
Anymore and I'd be 
the rear up all over the shop, still that probably saves the transmission components ! and I can't afford to upgrade any more bits for a while (including any engine rebuilds, ECU etc. 
but 
to those that do 
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