The stock oil vapor separator works very well...in providing a means for the oil to precipitate out of the crankcase vapors, and return to the crankcase.
What it needed was to have more flow capability, without reducing the precipitating capabilities.
I decided to [basically] double the size of the vent hose going from the separator to the intake...by going with two hoses instead of just one hose. To do that, I needed to install a brass elbow.
"Where" to tap in that elbow was the crucial thing. The internal passages in the separator promote the oil precipitation out of the vapors. So I wanted to tap into the same top chamber as the stock outlet is. And I wanted to be able to route that second vent hose next to the stock hose...to maintain the stock look.
I determined that an elbow installed on the upper side of the separator...in the hole drilled on the side, as shown in this picture...would accomplish all of the above.
Some may wonder as to 'why' two hoses? As I alluded to priorly, with a larger diameter hose for the blowby to pass through, the velocity of the flow is less: the blowby travels slower. The stock vent hose is about 5/8in diameter, and adding another hose of about the same size would give me the 'larger diameter' hose to slow the flow velocity down.
The objective is to let the crankcase vent...breathe...as it wants to and needs to, in order to keep the crankcase pressure down. And to let that breathing occur as slowly as possible to assist in the precipitation of the oil out of the vapors: let the blowby pass through the separator slowly to let the oil fall out of the crankcase vapors.
True, I could have just cut off the stock outlet on the separator and replaced it with a 1in. brass fitting and used a 1in. hose. That would have worked. But I liked the look of dual hoses coming up and over the motor and going to the catch can. So my going the dual hoses was as much an appearance choice as anything. But I did achieve the larger diameter flow path for the blowby gases with the dual hoses...and it looks good: close to stock, but different enough to notice.
