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21cc on stock pistons

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Old 11-16-2015, 10:07 AM
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Default 21cc on stock pistons

Hi guys,I'm going to order a cool head for my 08 banshee (stock) I was just wondering should I go for 20cc domes or 21cc domes ? Any ideas?, is it safe? ... thanks in advance.
 
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Old 11-16-2015, 01:27 PM
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The larger domes are going to be a safer bet to run pump gas. Not a lot of Banshee guys around here anymore unfortunately. I would try contacting the head manufacturer, or if your engine has been ported/stroked your builder may be able to help. In the end, you just may need to perform a good old fashioned squish test to make sure you are in the right compression range for your desired octane rating. I know some of the 250r forums are good resources to find the squish test procedure. Good luck!
 
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Old 11-16-2015, 01:30 PM
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Oh, and we're do you live that you are lucky enough to have an 08? I'm a little jealous, lol.
 
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Old 11-17-2015, 08:47 AM
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I would go with the 20cc's. I have 17's in mine and I need to run race fuel. I had my stock head milled .010 on my other one and can run super in it. My 4 mil has 180 psi cold compression and the other has 150. 165 and up is where you need race fuel and 145 and up for super. Check compression after you install them to see what fuel to run.
 
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