Helo Measuring Correct Rod length for Given Situations

[Jerry Poole]

Could someone on the forum please calculate the needed connecting rod length to obtain ZERO DECK HEIGHT for the following? Engine Block Deck Height: 9.29"/236MM: Stroke: 3.40"/86.4MM. Gasket thickness 0.065"/1.65MM. ( These 3 items are constant). Piston: #1: Compression Height 1.32"/33.5MM. Deck Clearance: 0.027 " POSITIVE",: Pin diameter: .787"/20MM: Piston #2 Compression Height 1.20"/30.6MM, Deck clearance: "0", (15CC DISH), Pin diameter .827"/21MM . The Ring package for both pistons will be 1MM top ring, 1.2MM 2nd ring and 2.8MM for the 3rd ring. Thanks for any assistance and insight. Jerry

[strokersix]

Maybe I'm missing something in your question. Should be deck height minus compression height minus 1/2 stroke equals connecting rod length.

[pdq67]

Try here!

http://www.wallaceracing.com/Calculators.htm

And think about using as long a rod that you can afford to lighten up the piston.

pdq67

[af2]

6.27"

3.4 divided x 2 = 1.7 +1.32= 3.02 .... 9.29- 3.02= 6.27"

#2 minus .120 or a 6.39" rod

[gmrocket]

You say zero deck for both but your first piston says .027" positive? That's not going to be zero if you want your final piston to head clearance to be .038"

Rod would need to be 6.297"

You don't want .065" clearance do you?