65. Catch me if you can

With the SLC down for fuel issues I thought it would be a good time to knock another item off my to-do list.  Something I wasn’t keyed in on when I originally installed my engine was the fact that these LS motors are somewhat notorious for oil ingestion via the PCV system.

The LS3 has 2 PCV lines; 1 connecting the oil valley + driver side valve cover to a port located behind the throttle body and another connecting the oil filler neck to a port upstream of the throttle body.  Among the LS crowd, the first line is known as the “dirty side” and the second as the “clean side” – apparently the dirty side is very dirty and the clean side is only slightly dirty.  The recommended solution is to install an oil catch can on both lines before vapors are pulled back into the engine.  Qualitatively, about 90% of the problem is caused by the dirty side, so if you’re only going to add one can, that’s the side to address.

I had read about these rumblings regarding dirty PCV a while back but didn’t really think much of it until recently.  I had removed my intake tube to mess around with my MAF sensor location and noticed a good sized oil puddle right at the throttle body blade.  From what I’ve read, in higher mileage engines the interior of the intake is usually caked in oil residue due to the high oil pullover of the factory PCV system.  Seeing the oil after only ~1000 miles convinced me I needed to do something.  I opted to only address the dirty side – I’ll come back in a few thousand miles and decide whether the clean side needs addressing as well.  At ~$160 a can these things aren’t cheap!

The integrated PCV schematic for my engine.

It seems the “IT” oil catch can is made by Mighty Mouse Solutions.  However, the cans are configured with an air filter which allows oil fumes to fill the engine bay.  This also eliminates PCV completely; instead of vacuum pulling crankcase pressure it’s simply vented to atmosphere.  I’m not likely to be labeled an environmentalist but I wasn’t a fan of having my crankcase vented straight to atmosphere.  I also wanted to retain the vacuum aspect of the PCV system so I opted to go with the Elite Engineering catch can available through Brian Tooley Racing.  Ironically, it’s a little cheaper to purchase this from BTR as opposed to buying from Elite Engineering directly, go figure!  This setup retains the factory PCV system but adds the filtering capabilities of a catch can.  It’s also sealed so no oil vapors leaking into the engine bay.

Cross-section graphic from Elite Engineering.
The kit comes box-within-a-box style, a sealed Elite Engineering box is packed into a cardboard Brian Tooley Racing box ;). You also get a BTR sticker!
Package contents; the catch can is really nice.  It’s fully machined aluminum and has good weight to it.  I don’t know why something weighing more makes it feel like it’s a quality piece but I guess weight optimization isn’t critical in this case.  Some fuel-approved hose, fittings, and a mounting kit.  The mounting kit isn’t usable for our application.
Looking down into the inlet; the filter media appears to be machined stainless steel curls.  I imagine this is a superior filtering element than something like steel wool since it won’t yield or compress over time, thereby causing unwanted restriction.  The larger surface area may also help with oil/fuel nucleation.
Underside of cap.  Air flows through the 7 central holes, hits the bottom of the tank, then comes back up and around the central silver body.  PCV air is then pulled through a fitting located on the side.
Unfortunately the really nice anodized aluminum bracket doesn’t work for our application so I ghetto-fabbed a steel piece.  Low tech, but it works.
Installed on the forward bar of my rear chassis brace.
Plumbed and ready to suck!

**UPDATE: After about 200 miles I collected a surprising amount of oil in the catch can.  I highly recommend this upgrade, I’m now a believer!


About an ounce of oil collected after about 200 miles of driving!

3 Comments Add yours

  1. LS3 Swap says:

    Did you connect your passenger side (clean) port to the dirty side of the catch can? It doesn’t look like your initial drawing matches your installation. Pictures can be confusing though.


    1. Cam says:

      Hey there, good question – I do not have the clean side of my PCV system hooked up to the catch can. There is a specific clean side can you can purchase (made by Mighty Mouse I believe) but I opted only to install the catch can on my dirty side.


  2. LS3 Swap says:

    So, you tee’d your valve cover ports together to be the clean side? Then your dirty side is your valley cover? Seems like that should work well.

    My current setup has an open port on the driver’s side. I’m trying to determine if I should plug it or connect it to the clean side. I’m not currently running a catch can, but probably will later this year.


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