Cam Cover Foam Filters

[GOLDCYLON]

Originally Posted by Paul Workman

Ask and you shall receive!(Pardon the look of my covers, but they're going to be painted here in a week or so.)

P.

Nice post up thanks Paul !!!

[flyin ryan]

Scotchbrite will work better than the factory 'Foam' if installed correctly. Have to remember the idea of it is to seperate the air from the oil, keep the oil in the engine & pull out only the vapors. Fold the Scothbrite onto itself once or twice (will be two or three layers thick), then pin it in place with the wire.

[billybaloneey]

While searching for a substitute, before I began this thread, I did come across a very think Scotchbrite pad. It was in the form of a 2' in diameter stripping pad used on heavy duty floor buffers...the pad is designed to strip wax from floors. The pad is about 3/4" - 1" in thickness. The Scotchbrite material is a bit more dense than the original filter foam, but it's close. I think the suggested copper scrubbing pad is closer in material density/weave.

As far as long term usage, I think the Scotchbrite pad might be a safer choice. If it deteriorates or breaks down...and drops down from the cam cover onto the head and gets into the engine through the oil, the engine would have a better chance of digesting a strand of Scotchbrite material as opposed to a strand of copper. Although the chances are probably slim a strand of copper would break off.

In either case, I've not been able to find...in the service manual...a recommended servicing/replacement frequency for changing these filters, so it must not be a serviceable item. I can't imagine GM expecting anyone to have the cam covers removed on a regular basis to change those two tiny filters.

For anyone trying the Scotchbrite replacement option...because of the materials density, I think the occasional quick spray/shot of de-greasing chemical, where the tube enters the cam cover, it might be a good idea to rid the material of any oil build up. I'm just thinking out loud and trying to think logically, I'm not speaking from experience.

[bdw18_123]

Originally Posted by flyin ryan

Scotchbrite will work better than the factory 'Foam' if installed correctly. Have to remember the idea of it is to seperate the air from the oil, keep the oil in the engine & pull out only the vapors. Fold the Scothbrite onto itself once or twice (will be two or three layers thick), then pin it in place with the wire.

Good info, Ryan. I didn't want to change the properties of the filter without knowing exactly what its function is. Now that I know, maybe going to a more dense (like scotchbrite) material would be a good idea to help keep more of the liquid oil out and only let the oil vapors through.

I don't think those filters are intended to be changed out on any kind of regular basis. I think it is too coarse to get clogged, and even scotchbrite I think is too coarse to worry about changing them out. If your oil has thick enough particles in it to clog those filters, you have a serious problem!

[Jagdpanzer]

Crankcase fumes are not drawn through the cam cover filters but are handled by the PCV system which directs the fumes to the intake plenum via the hose connection just behind throttle body. The cam cover filters are for the fresh air being drawn into the engine from the air horn fittings. As this air has already passed through the main engine air cleaner it appears the cam cover filters could serve more like baffles to prevent the oily mist in the cam box from finding its way upstream into the air horn or for preventing larger objects that may have got around the main engine air cleaner from passing into the cam box.

[billybaloneey]

Originally Posted by Jagdpanzer

Crankcase fumes are not drawn through the cam cover filters but are handled by the PCV system which directs the fumes to the intake plenum via the hose connection just behind throttle body. The cam cover filters are for the fresh air being drawn into the engine from the air horn fittings. As this air has already passed through the main engine air cleaner it appears the cam cover filters could serve more like baffles to prevent the oily mist in the cam box from finding its way upstream into the air horn or for preventing larger objects that may have got around the main engine air cleaner from passing into the cam box.

Thanks for the functional explanation.

[flyin ryan]

In reality, fumes 'Do' go out the tube to the throttle body. Almost like the way a venturi will 'Draw' on a tube or booster. It's well docmented the problems Lotus had with crank-case pressure, they had too much, to think that fresh atmospheric air some how finds it's way into the tube connected to the cam covers, going against the grain per sa, is wishful thinking. Remember the 70's early 80's Sm. Blk. Chev.'s that had a tube going from one of the valve covers to the air cleaner base? Same idea...That tube we are talking about has the ability to draw fresh air, but the reality is something different.