Originally posted by flySI
accordhybrid- Ummmm, the b16a has a very good bottom end. It comes from the factory pretty well balanced and is the only production engine that I can think of that has a near perfect rod-stroke ratio. Perfect R/S ratio is 1.75:1 and the b16a is a 1.74:1 so you see in stock form the bottom end is capable of around 9000 rpms safely IMO. Anything over that and I would have to agree that the rods will need at the least a bolt upgrade.
R/S ratio is nothing more than a fall-out number, has nothing to do with engine stresses, only the amount of friction that will be developed between the piston and the cylinder. As long as the rod isn't so short that the crank tries to push it through the cylinder at anything over 1000 RPM, you should be fine.
All in all, R/S ratio is a nice figure to keep track of, but isn't something to worry about. It is not a measure of potential power development, nor is it an absolute measure of how much stress the rod will see, it is just a ratio someone figured out you can get by measuring two items in the engine's structure.
For revability of an engine, the more important items to look at in the lower end are rod bolt strengths, tensile and compression strength of the rods, weight and peak speed of the pistons, and THEN look at the casting strength of the pistons along with the R/S ratio. By the time you really need to worry about that last bit though, chances are you will be floating valves too much to rev much higher anyways...