UPDATE: The page below talks about a blow by problem that I thought I was having. I later found out that I was supplying too much oil to the turbo and pressure was making it leak by the seals. An oil restrictor was placed in the line and the problem was solved. I have yet to see any oil in my catch can.
Oil Catch Can
Ever since I purchased Red Beast she has had a blow by problem. I often puff smoke when letting off the gas and sometimes it is really bad when I first start the car (just sitting at idle). Since sucking oil into your intake manifold promotes knock as well as embarrasses the hell out of you I decided I wanted to put a catch can (air/oil separator) on the car. Purchasing a pre-made catch can off the internet will cost you $50-$100 so I decided to build my own. This way I could save money, have a little project to keep me busy, and build it to the dimensions that I wanted.
While deciding on how I was going to build it I came across this website. His can looked so good (hmmm, that sounds a little funny ) that I figured I would just steal all his ideas and claim them as my own. Many thanks to Matt Yates!
A quick trip to the hardware store and Piggly Wiggly to get some supplies. I already had some old 2" PVC pipe and the stopcock drain valve but total costs new would have been about $20 for all of this (including the 3/8" hose):
After stuffing the pipe with the scouring pads I put the caps on and blew through one of the fittings to make sure air would flow through before getting out the glue. I slapped a couple of quick coats of flat black on it for looks.
When I first decided to build the catch can I wanted to install it under the hood. The only problem was there wasn't really a good place to do this. The can was about 8" long and I needed plenty of room on the bottom to open/close the drain valve. I finally found a good place, right behind the right front tire. There is a flat place in the wheel well where the can fit perfectly. Don't worry, I ran an autocross a few days later and my tire didn't rub on it:
There isn't a good way to take a picture of the rest of the installation so I'll just give a little discription. I used 3/8" heater hose since that was the size of the nipple on the intake manifold and PCV valve. The path of flow is:
cam cover -> PCV valve -> 3/8" hose to bottom of catch can -> 3/8" hose out the top of catch can -> intake manifold
So how's it working so far? Well, the can has only been in the car a week and I have put very few miles on it (I only drive about 1000 miles a year in this car). I keep checking it but I have not found any oil in it yet. I can pull the PCV valve out of the cam cover and there is definitely a good vacuum through the system. I believe it is just taking a while to coat the insides of all the new hoses and scouring pads before there is any volume of oil to drain out of the can. The catch can did help determine that my turbo is the cause of the smokey exhaust since that has not stopped. I believe that the oil is exiting straight through the turbine and not getting to the compressor side because I do not have, as far as I know, lots of oil in my intercooler. I'll have to address the smokey exhaust later (probably by installing an oil restrictor in the feed line to the turbo). But, at least I know that I no longer am getting oil in my intake.
Oh, one more thing, I have been researching running a slashcut tube in my exhaust system to create a continuous vacuum by the venturi effect. This should be better than my current setup since as soon as I go into boost my vacuum stops. This, of course, is when I need it the most. I've lost my link to one of the pre-made slashcut pipes (someone send me a link if you have one) so it will have to go on the back burner until I find another one. I bought some pipe to make my own but I don't see that happening in the next month or so.