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So, been looking at the possibility of turboing my N/A BA barra. Id been doing some research on it and decided to look into some math on it. The BA XR6 has a compression ratio of 9.7:1, and the Ba XR6T has a compression ratio of 8.7:1. I wanted to find out what thickness of head gasket would lower the compression enough. I found values for what I could.
Swept volume = pi x bore radius^2 x stroke. which is pi x 4.613^2 x 99.31 = 663.911cm^3 this is the displacement per chamber, just with more decimals compared to 664.

Bore: 92.26mm This gives a compression ratio of 9.672:1.
Stroke: 99.31mm
Chamber Volume: 66.3911cc
Gasket Thickness (assuming steel): 0.76mm To active low enough compression for turbo, I increased the gasket thickness in the calculator.
Gasket bore: 93mm
Deck Clearance: 0.3mm
Piston dish: 3cc
Compression Ratio (CR) Calculator - Good Calculators

2mm = 8.812:1
2.28mm = 8.641:1
In comparison, the FG XR6T is 8.47:1

THIS MATH ONLY APPLIED TO THE BA FALCON BARRA 182.

So the age old, "just slap another head gasket on it" seems to work. I havent put this into practice, but I might possibly in the future, however with the additon of ARP studs.

Hope this may give some hope to those looking to Turbo.
 

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So, been looking at the possibility of turboing my N/A BA barra. Id been doing some research on it and decided to look into some math on it. The BA XR6 has a compression ratio of 9.7:1, and the Ba XR6T has a compression ratio of 8.7:1. I wanted to find out what thickness of head gasket would lower the compression enough. I found values for what I could.
Swept volume = pi x bore radius^2 x stroke. which is pi x 4.613^2 x 99.31 = 663.911cm^3 this is the displacement per chamber, just with more decimals compared to 664.

Bore: 92.26mm This gives a compression ratio of 9.672:1.
Stroke: 99.31mm
Chamber Volume: 66.3911cc
Gasket Thickness (assuming steel): 0.76mm To active low enough compression for turbo, I increased the gasket thickness in the calculator.
Gasket bore: 93mm
Deck Clearance: 0.3mm
Piston dish: 3cc
Compression Ratio (CR) Calculator - Good Calculators

2mm = 8.812:1
2.28mm = 8.641:1
In comparison, the FG XR6T is 8.47:1

THIS MATH ONLY APPLIED TO THE BA FALCON BARRA 182.

So the age old, "just slap another head gasket on it" seems to work. I havent put this into practice, but I might possibly in the future, however with the additon of ARP studs.

Hope this may give some hope to those looking to Turbo.
When talking to Brad at atomic, regarding a head gasket for a fg na motor to turbo he suggested his 1.1mm gasket and said the stock ford one is 0.50 thick.

Using your math above moving from a 0.50 mm gasket to a 1.1mm gasket would drop the CR down 0.49 points. This would put us somewhere in the 9.81:1 when using a FG 10.3:1 engine.
a 1.3mm gasket would drop the CR down 0.65 points (somewhere in the 9.65:1 when using a FG 10.3:1 engine)
 

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When talking to Brad at atomic, regarding a head gasket for a fg na motor to turbo he suggested his 1.1mm gasket and said the stock ford one is 0.50 thick.

Using your math above moving from a 0.50 mm gasket to a 1.1mm gasket would drop the CR down 0.49 points. This would put us somewhere in the 9.81:1 when using a FG 10.3:1 engine.
a 1.3mm gasket would drop the CR down 0.65 points (somewhere in the 9.65:1 when using a FG 10.3:1 engine)

So if you use a 0.075 Cometic, it would be roughly 9.3:1 on an FG NA. So why is everyone who does an NA to turbo running a 1mm and reducing timing when they can run the thicker hg? I am tossing up between the 1.1 or the 1.9 to run 98 and e85
 
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