Measured all my deck heights and determined what shims I need on the cylinder bases to get my minimum 8.0 compression ratio. I used this web site to help with the calculations: http://www.csgnetwork.com/compcalc.html
* Compressed head gasket: when I measured the thickness of my previous head gasket it was about 33% thinner, at 1.0 mm (a .060" gasket = 1.5mm).
Cylinder #1
Bore = 92mm Stroke = 82mm Head Gasket Bore = 92mm Compressed Head Gasket = 1.0 mm (* see above) Combustion chamber volume = 59.2 cc Piston Dome volume = 0 (flat top pistons) Deck clearance = 1.64mm (** see below) COMPRESSION RATIO = 8.1:1 ** Deck clearance: without a barrel shim the deck height was -.61 mm (.61 mm above the top of the cylinder). If I add a .060" (1.5mm) shim, and a .030" (.75mm) shim then => 2.25mm - 0.61mm = 1.64mm
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Cylinder #2
Combustion chamber volume = 59.0 cc Deck clearance = 1.72mm (** see below) COMPRESSION RATIO = 8.07:1 ** Deck clearance: without a barrel shim the deck height was -.53 mm. If I add a .060" (1.5mm) shim, and a .030" (.75mm) shim then => 2.25mm - 0.53mm = 1.72mm
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Cylinder #3
Same numbers as #1 cylinder
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Cylinder #4 (This cylinder has a chamber volume and deck height much different than the others, so the shims need to be different to get a similar compression ratio)
Combustion chamber volume = 62.2 cc Deck clearance = 1.19mm (** see below) COMPRESSION RATIO = 8.1:1 ** Deck clearance: without a barrel shim the deck height was -.71 mm. If I add a .045" (1.15mm) shim, and a .030" (.75mm) shim then => 1.9mm - 0.71mm = 1.19mm
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Running total of hours spent: Tonight = 3.0 hours Total = 29.5 hrs
Deck height is a negative (-) number because piston is ABOVE the cylinder.
