CTR or P30's Pistons? on B18b block
03-10-2005, 07:33 PM
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CTR or P30's Pistons? on B18b block
Which would you choose on a B18b block and head? Will that dome shape CTR pistons clear the head? No guessing I need a striaght foward answer, with supporting facts. I've heard the c/r for CTR pistons is 12's and P30's pistons are 11's. Thanx if anyone can help out.
03-10-2005, 08:06 PM
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If you are using the stock block and head, the compression will be around 11.7:1 for the CTR pistons and around 11.3:1 for the P30 pistons. As long as the stock head and cams are being used, valve clearance won't be an issue. Those are both good compression ratios for pump gas (assuming the motor is tuned correctly), so I would go for the CTR pistons for the higher compression ratio. If in doubt, make sure that you clay the motor to make sure that there is enough room.
03-10-2005, 08:35 PM
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I think with CTR pistons the compression will be higher than 11.7. The factor that the compression calculators dont take into account is that the piston top sticks up slightly higher than the deck at TDC, whereas the other pistons sit flush. I'm not talking about the dome, but the edge of the piston.
03-10-2005, 08:48 PM
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Originally Posted by Master Yodub
I think with CTR pistons the compression will be higher than 11.7. The factor that the compression calculators dont take into account is that the piston top sticks up slightly higher than the deck at TDC, whereas the other pistons sit flush. I'm not talking about the dome, but the edge of the piston.
03-11-2005, 10:23 AM
#5
been there done that
assuming the block is stock and the head has not been milled running an oem 3 layer headgasket, compression with ctr pistons is at 12.42:1. with p30's it'll be at 11.04:1.
i got my numbers from http://www.zealautowerks.com/
i got my numbers from http://www.zealautowerks.com/
03-12-2005, 11:28 AM
#8
been there done that
to get the pct's to fit onto the stock rods, you will have to mill 1mm off each side of the small end of the rod. you dont have to do this with the p30's. claying it is always a good idea so you know where everything stands.