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Old 11-29-2005, 04:29 PM
Super Streeter Super Streeter is offline
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There are some basic ideas about rod length.I never gove it much though as a means of increasing performance,but here is what I think about it anyway.

I would never pass up the chance to gain stroke if I needed it just because it would hurt the rod ratio.Of course there are extremes,but in most well rounded combinations this can be taken as fact.I would also never give up piston strength or resort to using a comprimised ring package just to get more rod into an engine.

Short stroke engines can sometime use longer rods as a means of reducing piston weight and improving ring stability,but too much rod can make an induction signal that is too strong on an engine with a limited induction system,so even on an unlimited induction engine,I wouldnt go over about 1.9:1 on the rod ratio.My preference would be to shorten the deck height of the motor and get the rod ratio back down to 1.7:1.

My last theory is the most noteworthy.When in doubt and room permits,build any 90 degree V8 engine with a rod ratio of 1.7:1.I say this not because this is a magic number,but because it is in the middle of where rod ratios typically fall,so matter what anybody else in your class has or claims to have,they will never have any signifigant amount more or less power then you just because of rod ratio.

As a point of interest,my own personal engine is a bigblock chevy built for class racing at 440 cubes,and I use a 3.76" stroke and 6.385 rods with a standard deck height block,and the combination is about as well rounded as it gets,and guess what the rod ratio is.

1.69:1.
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