rod ratio

Good morning all,

Is rod ratio still as much of a concern given the advancement and improved quality of parts?

Or is it "best practice" to get the best ratio possible?

thanks for the advice

I believe the “ideal” rod ratio is dependent on the application? Should it be a big concern for the 5000 rpm engine that’s pushing you’re ‘77 LTD down the road, probably not. You can only alter the rod ratio so far with the parts that are currently available, if you stick to typical combos. If you wanted to get crazy you could also start “crossbreeding” with parts from other brands like the guys did in the olden times This often required modifications but desperate times called for desperate measures.

I understand side loading of the piston...just wondering if builders had a general rule of thumb....

i.g. 632 ci vs 598 ci...
598 has better rod ratio but does it come down to "acceptable" trade offs if you will?

The shorter the rod, the more the cylinder wall loading will be. The longer the rod, the more the main web loading will be ...
1.60 to 1.75 is usually good for a production type block but, there are things which will vary that ... especially peak power output or whether the block water jackets have been partially filled or not.

Sometimes you just have to accept whatever you get no matter what it is.