This one is a bit long...

I finally got around to finishing the design of my catch cans and getting them built. But first, a little history...

Some of you (with no life) may have read through the Stupid PCV question thread and remember that several of us were trying all sorts of different things a couple years ago to find a catch can setup that worked. Long story short, I never found anything I liked.

Home Depot filters crack (and look "ghetto" IMHO), inline filters clog or collapse, and after-market catch cans are too generic and don't really remove much oil other than what little can separate due to gravity. And you still end up with oil in the pipes, or even worse...in the engine bay. So during the course of my rebuild, I've been mulling over an improved CC setup as the car comes together and everything falls into place.

I'm hoping I finally found something I like this time. But before I go any further, let me just state that what I've come up with is based on a lot of research, a bit of suspended particle theory, some common sense, and a hunch. So there's a chance that I may be full of shit and none of this will work either.

Most inexpensive (*cough* *cough*) aftermarket catch cans work on the principle of pressure drop and a change in velocity to separate oil from air. The problem is that crankcase gases contain sub-micron oil aerosols that like to play by their own rules...not just big drops of oil that respect the catch can's wishes. So while the common catch can will do a fair job of removing those larger oil droplets, the aerosols will happily travel right on through them to settle in your intake, IM, and engine bay (if you have an open breather). For some people this isn't a problem or even noticable, but for others (me in particular) it is annoying as hell and unacceptable.

The trick to stopping these little nasties (in theory) is to use something called a coalescing filter. This type of filter uses glass microfiber strands to "coalesce" small droplets into bigger ones, until gravity can take over and the oil begins to settle out of the gas stream. Industrial coalescing filters are big multi-layer monstrosities that would never fit in an engine bay...and most of us couldn't afford them if they did. So my mission was to figure out how to simplify the idea and make it fit into a small catch can, and still function as well as possible.

Just as an FYI... Those Home Depot (Husky) and similar air compressor filters use a sintered bronze filter element, and flow from outside the filter in, towards the middle. This is both the wrong material and the wrong flow direction for removing anything smaller than about 5-10 microns.

After a lot of searching, I found a company who could supply me with some raw filter element material that will work at crankcase temperatures, is happy with the chemical soup, and has a low pressure drop. It is a glass microfiber material impregnated with a resin, and is designed specifically for oil vapor coalescing. The filter is designed to be permanent and anti-clogging, and should never need to be changed. If it does ever become clogged, it can simply be rinsed out with some gas.

I also sourced some perforated aluminum to use as a filter screen, which helps secure the filtering material and provides surface area for the oil droplets to collect on. Finally, I added some internal baffling to help with air flow through the can.

Note: I'm respectfully claiming my right to not show any internal pictures of the cans at this time.

So with all that said...on to the finished product.

I'll be running the basic sealed two-can setup; stock PCV valve > catch can > check valve > IM on one side, and VC breather > catch can > intake on the other. If you've been playing along, you've realized by now that I'm an anal retentive and picky SOB; I just couldn't bring myself to slapping a couple of round cans on the firewall and calling it done...not that there is anything wrong with that of course .

For the can on the VC side, I'm re-using the one I originally made back when I was experimenting with the Husky filters, but modified it to include the coalescing filter. It has a sight tube on the side, and will connect to the VC with a -6 AN line. It's designed to mount to the clutch line bracket, and the drain hose runs down to a separate bracket on the frame rail where it meets up with a drain valve.



Here it is polished up and sitting in place. You can also see the bracket and drain valve just below and in front of it.



For the can on the PCV valve side, I decided to get creative since I was starting from scratch. Due to the size of the filter material and the aluminum stock that was available, I was a bit restricted in what size I could make it, and I wasn't quite sure where to mount it or even what shape it should be.

After relocating the coil packs, I was staring at the motor and drinking a cold one when it just sort of hit me that the ideal place for a catch can would be hanging off the end of the IM. It is the perfect location for routing the lines, is out of the way but still accessible, and IMHO just looks cool as hell sitting there.

I grabbed my trusty cardboard and hot glue gun, and started experimenting with ways of mounting something. As is usually the case, the simplest idea turned out to be the best. I ended up with a square 2-1/2" can and a formed bracket that attaches to the now unused harness bolt holes on the IM. I used 3/8" NPT weld bungs for the inlet and outlet so that I could change fittings later if I want (in retrospect, I should have used 1/4" on this can...3/8" is too big and unnecessary). The plan for now is to go with nickle plated elbows into rubber hose for connection to the IM and PCV valve.

The drain valve is the same type as the one on the other can, and is screwed directly into a weld bung on the bottom side. (There will be a drain hose running down to the frame rail behind the motor). To save space and try something different, I added an industrial sight window on the side rather than a tube, which makes it look just a bit more professional.



Here it is bolted up to the end of the manifold. You observant types will probably notice that I switched to gloss black with a clear coat for the IM...that raw aluminum just wasn't working and finally got the best of me.



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Update:

After 1000+ miles on the car since the rebuild, I've collected about 3/4 cup of oil in the VC breather catch can, with ZERO oil in the intake snorkel. Even swabbing a q-tip in the line coming from the can and in the intake itself reveals no trace of any oil whatsoever.

So it looks like the cans are performing at or beyond expectations so far. They are definitely out-performing anything else I've tried.

The pictures below were taken as soon as I pulled the intake snorkel off and drained the VC catch can, with a little over 1000 miles on the motor. The inside of the pipe has not been touched.



If you are interested in having one or two of these cans for yourself, PM me or check out this page.

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Ok. Enough with the catch cans and on to other things...

Almost from day one of this rebuild I have been fighting the wheel wells from hell. I tried just about every type of cleaner, paint, and coating there is, but still had areas that wouldn't dry. Well that hell is finally over, thanks to Herculiner. For those of you that aren't familiar with it, it is a polyurethane-based roll-on bed liner that you can get in a quart-sized can for about $30. This stuff is down-right nasty, but worked beautifully. After cleaning off the still un-dried goop and wiping down the wheel wells with mineral spirits, I dabbed on two coats of Herculiner with a brush... and a couple of hours later I had a rock hard and DRY coating. Besides looking great, I'm fairly confident than my car is now capable of repelling a direct hit to the front wheel area with an RPG.



I also knocked out a few other projects, such as cleaning/painting some suspension parts, installing a new throttle cable, building the SS line for the AFPR, and polishing my TB elbow. I attached the throttle cable to the firewall close to the fuel filter with a 1/4" cable clamp, and then looped it under the IM. After the TB elbow was polished I cleaned and reattached my WAI nozzle to it.




Last but not least, I finally got around to rebuilding and modifying my power steering pump. There doesn't seem to be much information floating around on this subject, so once it was finished I took a break and wrote a tech article about it.



In the next part I'll get into the intake manifold modifications and plumbing, and wrap up the wiring details in that area as well.

Stay tuned!