Compression ratio...
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Re: Compression ratio... (A2 VW)
It decreases the compression ratio, the gasket does nothing for the stroke, that's determined by the crankshaft what the thicker gasket does is effectively make the combustion chamber bigger and that lowers the CR.
This might help you get a handle on what's happening
Compression ratio= total volume / chamber volume.
Total volume =displacement + chamber volume
Chamber volume =cylinder head chamber volume + deck volume + gasket volume
It decreases the compression ratio, the gasket does nothing for the stroke, that's determined by the crankshaft what the thicker gasket does is effectively make the combustion chamber bigger and that lowers the CR.
This might help you get a handle on what's happening
Compression ratio= total volume / chamber volume.
Total volume =displacement + chamber volume
Chamber volume =cylinder head chamber volume + deck volume + gasket volume
Re: Compression ratio... (ABA Scirocco)
Or put more simply, the ratio of cylinder volume at BDC over the cylinder volume at TDC. For example, a 10:1 ratio means the volume at BDC (bottom dead center) is 10 times the volume at TDC (top dead center).
Without getting into the mathematics, adding a thicker head gasket increases both the numerator and denominator equally, but not proportionally, and you end up having a proportionally larger bottom number. The result is a reduced ratio.
See, I said it would be simple.
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Or put more simply, the ratio of cylinder volume at BDC over the cylinder volume at TDC. For example, a 10:1 ratio means the volume at BDC (bottom dead center) is 10 times the volume at TDC (top dead center).
Without getting into the mathematics, adding a thicker head gasket increases both the numerator and denominator equally, but not proportionally, and you end up having a proportionally larger bottom number. The result is a reduced ratio.
See, I said it would be simple.
Joined
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10,420 Posts
Re: Compression ratio... (A3Jetta)
Thinner head gasket if you can find one, or shave the head.
Thinner head gasket if you can find one, or shave the head.
Re: Compression ratio... (ABA Scirocco)
yea the guy who is P&P my head said he will shave it like 0.060 to increase the compresion one point BUT i have a question. If i get over sized pistons later down the road will the compresion be to high with the head shaved?
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yea the guy who is P&P my head said he will shave it like 0.060 to increase the compresion one point BUT i have a question. If i get over sized pistons later down the road will the compresion be to high with the head shaved?
Joined
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10,420 Posts
Re: Compression ratio... (8v-inside)
Perhaps, if need be you can get thicker gaskets too. If you need any info about that, check with the guys in the forced induction forum they do that sort of thing all the time. It would be a good idea for you to cc your head and block to see where you are at now, that way you can make intelligent decisions based on hard numbers rather than guessing or taking someone else's word for it.
Perhaps, if need be you can get thicker gaskets too. If you need any info about that, check with the guys in the forced induction forum they do that sort of thing all the time. It would be a good idea for you to cc your head and block to see where you are at now, that way you can make intelligent decisions based on hard numbers rather than guessing or taking someone else's word for it.
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