Take a 100,000 mile piston (w/ oil ring intersection) and one without. Driven the same...
I promise you the one with the oil ring intersection will have a greater chance of blowby...
Just take a look at the piston...pretty simple really.
Rod ratio doesn't have to much to do with anything for most enthusiast. It is part of engineering and can not be ignored.
The 331 for example has an offset wrist pin to improve the rod ratio. They wouldn't design it that way if there was not a reason.
In my opinion it is literally unethical to prescribe to someone the 'longer rod' with a wrist pin that goes up into the oil ring land area of the piston unless they plan to race it. The shorter rod with the same cubes would be a better fit for a true street car.
From CHP referring to 331's and 347's.
:
Why a 331 instead of a 347? CHP's Chris Huff says the company originally developed the 331 in response to the early 347's reputation for consuming oil and wearing out prematurely--fine for racing but not so great for the street. Early on, the long rod used with the 347 mounted high up on the piston, requiring a wrist-pin hole that protruded into the oil-ring lands. These early pistons were also race-only, with more piston to-wall clearance than typically used on the street. Although CHP has improved the street 347's shortcomings by designing its own piston with off-set wrist-pin mounting and a slightly shorter rod, which doesn't need the wrist-pin holes in the oil-ring lands, it still offers the 331 for builders who continue to be gun-shy of the 347. According to Huff, you'll get great oil control and 100,000 miles of service from either of the CHP 331 or 347 street engines.
Like with anything, as long as its done correctly.
