S2000 Catch Can
By Rob Robinette
The AP1 S2000 has a habit of spitting big blue oil clouds while on the track in extended right hand corners. An oil catch can will solve the problem and keep you from scaring the crap out of people behind you in fast sweepers. The stock engine has a PCV (positive crankcase ventilation) valve that allows the intake to suck blow-by gasses out of the valve cover. When the throttle butterfly closes (like during a shift) a great vacuum is created in the manifold. This vacuum sucks air/blow-by gasses/oil from the valve cover into the manifold. Oil can build up near the valve and get sucked into the intake where it's burned and turned into blue smoke. By placing a catch can in this hose you can trap oil and keep it out of the intake.
There are two vacuum lines that can be tapped for a catch can. The most common is the PCV valve line. This line is the cause of most "blue smoke" problems. The other location is the large line that runs from the front of the valve cover to the intake in front of the throttle butterfly. If you're not concerned about keeping emissions legal the best solution is to cap the PCV valve and put a catch can in the large hose. This is what I did to my S2000 race car. The PCV Valve uses 3/8 inch inside diameter hose and the large front vacuum line is 1/2 inch inside diameter. I sourced the vacuum hose and caps at Autozone.
For my emissions legal catch can I sourced most of it from Home Depot. It consists of a small (too small, see Update 2 below) compressed air water separator (air tool section of the store), two 90 degree elbows with 3/8 inch hose barbs on one end and male 1/4inch NPT thread on the other (plumbing section), and some plastic hose.
Update--The plastic hose pictured ended up collapsing under vacuum so I upgraded to two 18 inch long pieces of 5/16 inch fuel injection hose sourced from any auto parts store (thanks for the suggested change Matt).
Update 2--The catch can pictured was too small and oil was simply blowing right through the tank. I have seen the next size up air/water separation tank installed in the same place and it works well. Matt would catch about a 1/4 of a quart every track session or two.
Small Catch Can in PCV Valve Line
I used 5/16 inch hose but you can just pop out the PCV valve shown above and take it to the auto parts and hardware store so you can get the right size hose and 90 degree elbows. The elbows are 3/8 inch barbed on one end for the hose, and 1/4 inch NPT thread on the other. The length of hose and mounting position are not critical but if you have a shock tower bar mounting it there works well. I have seen catch cans mounted on the stock air box too, but you'll need about 21 inch long lines to make that work. The water separator has a valve on the bottom to empty the trapped oil. You can unscrew the glass part of the separator and drain it back into the engine.
Racing Catch Can (not emissions legal)
