Yup , i know that... but mayb some of us can share more info...something like..(this figure IS NOT true one)...i guess only :hmmmm:
a) 0.7mm (compression 85.5:1) safe to boost max 1.5bar
b) 1.2mm (compression 85.0:1) " boost max 1.8
c) 1.6mm (compression 84.5:1) " boost max 2.2
who can share or advise on this...tq
Bozz, it doesn't work that way .....
read this ....
http://www.everything2.com/index.pl?node_id=766464
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Examples:
basic
Stroke 100mm
Bore 87mm
gasket thickness ... i dint know but worked around
comp ratio = (cylinder volume + combustion chamber volume)/ combiustion chamber volume = 9.5
combustion chamber volume = some complicated stuff + head gasket volume
- head gasket volume = (.5bore ^2) * pi * height(thickness) = 69937.3965 (using algebra and solving for this in above formula w/ the 2 knowns)
cylinder volume = (.5bore ^2) * pi * stroke = 594467.87
to achieve about ~ 8.9:1
assuming
X = desired compression ratio
TCV = CCV + G = total combustion chamber volume
CCV = combustion chamber
G = gasket volume = (.5bore ^2) * pi * height(thickness)
using some algebra that would be tedious to type we get:
Cylinder volume = (X - 1) TCV .. some more algebra etc
To find a thickness to get u around 8.9:1
594467.87 = 7.9 * (69937.3965 + G) more algebra solve for g or shouldve done it earlier..
G = 5311.70095 (volume of addditional gasket) now solve for thickness
assuming the new gasket has the same bore as the cylinder (87mm)
additional gasket thickness would be ~.89 mm or ~.035 inches to achieve static 8.9:1 compression
an additional .025 inches or .635 mm should bring down the compression ration to about 9.0647:1
assuming the same bore as the cylinder.
Now u just need to know your original head gasket thickness.
Source from the above link & some other websites (rpw & EM). Figures purely theoretical.
Bear in mind that the piston tops are not flat landings ...
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