Although the formula I used was:
Volume= (ð x R3)/3 x [2 - 3xCos(angle) + Cos (angle) 3]
where 'angle' was the angle subtended by the sector of the sphere (that the dome represents) at the centre of the sphere. THAT was the difficult bit. This procedure allows you to do the calcs from just the height and width of the dome.
See Appendix to : http://www.totallytriumph.net/spitfire/skimming_your_head.shtml
If you want to measure the dome, place the piston in a bore, at a fixed height (best on a conrod, on the crank). Seal the bore with vaseline on the piston rings.
Theoretical volume of bore= ðR^2H
Measure the bore volume with a burette, as for chamber measurement. The difference from the theoretical volume is the volume of the dome.
John
--Previous Message--
: In this day of online resources I still
: keep a copy of the CRC Math Tables book
: at work. It can be handy for
: calculations like this.
:
: If the dome is really a true section of
: a sphere, you can calculate its volume
: using the formula:
: V = 1/6 x Pi x H x ((3 x R x R) + (H x
: H))
: Where H is the height of the dome,
: and R is the Radius of the dome on top
: of the Piston.
:
: I am not sure how I would try to
: measure this by CC(ing) the piston top
: so calculations sound good to me. The
: other option is to hunt the piston
: specs to confirm the 10cc that Steve
: mentioned.
:
: Doug L.
:
:
: --Previous Message--
: I believe the popup domes on the
: Hepolites will be about 10cc's.
:
:
:
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