Mark... If you are going to build an engine that is not going to rev very high and use a cam that will make power low down on the rpms by all means build an engine with a rod /stroke ratio of less than 1.6:1 .
If on the other hand you are a driver who likes to rev your engine at higher rpm's then a better than 1.6 ratio is desirable . As you may know.. the current F1 engines use a ratio around 2.5:1 which allows them to rev to 20,000 rpms for hours on end. I would hazard a guess that the rod ratio had a lot to do with the design of these engines, but being an engineer I would imagine that I do not have a clue as to what I am talking about. A low Ratio may hold up on the street for a period of time, but if you are building an engine for longevity a better ratio is desirable. Of course if you are building engines for others and don't really care how long it will last ........then it does'nt matter at all.
I am also a little confused as to what the head size has to do with Rod/Stroke ratio???
