educate me on rod length please.
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Joined: Jan 2000
Posts: 93
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From: Madera, CA
Rod length, stroke, and piston compression height must fit within the deck height of the block. I don't know the Gen III deck height, but the Gen I & II blocks are nominally 9.025" from the centerlne of the crankshaft to the top of the block deck. At TDC the length of the piston rod assembly on the crankshaft is 1/2 the stroke + rod Length + piston compression height (the distance from the centerline of the wrist pin to the top of the piston). So for example, a 383 stroker (3.750 stroke) w/ 6" rods requires a piston compression height of 9.025 - (1.875 + 6.0) = 1.15" (approximately for the piston flush with the deck). A piston CH of 1.125 would leave the piston 0.025 down in the bore. Many people deck the block flat to 9.00 height when they rebuild which would give a piston of 1.125 compression height. Look in the piston catalogs and you'll this is much more common than 1.15".
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Joined: Sep 2003
Posts: 88,393
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From: eville in
Originally Posted by 90NormZ51
Rod length, stroke, and piston compression height must fit within the deck height of the block. I don't know the Gen III deck height, but the Gen I & II blocks are nominally 9.025" from the centerlne of the crankshaft to the top of the block deck. At TDC the length of the piston rod assembly on the crankshaft is 1/2 the stroke + rod Length + piston compression height (the distance from the centerline of the wrist pin to the top of the piston). So for example, a 383 stroker (3.750 stroke) w/ 6" rods requires a piston compression height of 9.025 - (1.875 + 6.0) = 1.15" (approximately for the piston flush with the deck). A piston CH of 1.125 would leave the piston 0.025 down in the bore. Many people deck the block flat to 9.00 height when they rebuild which would give a piston of 1.125 compression height. Look in the piston catalogs and you'll this is much more common than 1.15".
i wish i could explain this so well 
