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Walker AirSep

datswite

Ken Ferrari
I installed a Walker AirSep on my Perkins 4.108 yesterday. It's bothered me that the Perkins doesn't have an air filter. I know marine engine rooms aren't as dirty as corn fields. But, my engine has low hours and runs like a top. The AirSep wasn't cheap, but, if it really does help with oil leaks and adds some real air filtering, it's a small price to pay to extend the life of the engine.

Foley's advertises the unit as designed for the Perkins. It's not; it's a universal kit. I incorrectly assumed that it would have everything I would need to install. It did not. At any rate, I made it work.

If anyone has any questions about the install, I'd be happy to share my experiences.
 
So Ken tell me about this Air walker filter.. ! How much work to modify ? does it seem to do the job ?? and how much ??
What extra parts did you need ??
 
The AirSep is really just a glorified air filter. The filter element can be cleaned instead of just replaced. The reason I chose the AirSep over an ordinary paper filter is because of the claim that it reduces oil consumption and leaks. The system is also supposed to quiet the engine by a few decibels (we'''ll see about that).

As designed, the Perkins 4.108 sends blow-by from the valve cover directly back to the combustion chamber (via the flame arrester/air intake) and burned. Any oil mist is essentially burned away, or it plugs up the ridiculous little air filtration holes in the flame arrester. Once those holes get plugged, you'''re starving the engine of air. Now you'''re wasting both fuel and oil.

The AirSep replaces the flame arrester with a traditional air filter. It also routes the valve cover blow-by back to the oil pan, i.e. recycles the oil rather than burning it. It'''s a closed system and the manufacturer claims that it creates a negative crankcase pressure which reduces oil seal leaks. While I'''m hopeful that this claim is true, I maintain a healthy amount of skepticism ''' keeps disappointment in check.

The installation wasn'''t too difficult. But, as I mentioned, Foley'''s claims that the unit is designed for the Perkins, and it'''s not. You'''ll need to fabricate a mounting bracket for the air filter, but the kit comes supplied with a piece of aluminum stock for that purpose. You also have to find a way to get the blow-by back into the oil pan. The blow-by line has a check valve that can be routed to the dipstick hole or an accessory port. I chose to route mine to the accessory oil-extractor port on the starboard side of the engine. I don'''t have the oil-extractor installed and don'''t plan to add it. The unused port is covered with a plate about 3/16''' thick. I drilled and tapped the plate to accept the check valve.

The only other issue is that the various hoses supplied with the kit are the wrong size for the air intake and blow-by nipple. However, they aren'''t so far off that you cannot make them work.

Foley's had the AirSep on sale over the winter for $450, I believe - a savings of $50. My kit was missing a few pieces, but Foley'''s mailed them to me. This is the universal kit, so you might find it cheaper elsewhere if you shop with that knowledge. I bought from Foley's because they said it was specifically for this engine.

The manufacturer claims that every major diesel manufacturer are including the AirSep as standard equipment these days. You can check them out at http://www.walkerairsep.com.

My boat is still on the hard for a few more weeks, so I haven't run the engine yet to test it. Here are some photos of the installation. The hockey puck looking cannister is a vacuum regulator. The brass fitting in the bottom photograph is the check valve.


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Keep in mind that the #2 reason you feed blow by back to the intake side is to put the crank case in to negative pressure. By looping back you will build up pressure in the crank case and oil will flow out of any place it can... Combustion and piston movement causes crank case pressure to increase. You must find a way to remove it..
 
I like you air filter Assembly. I also cant stand the no filter situation except i used a " rice boy" K&N on a short ram. Far cheaper but not much quieter..
 
Rene - You're not the only one wondering about pressurizing the crank case. Airsep is put on many boats, some OEM. So there must be more here. I went to the website and didn't get much of a technology explanation. I do know one needs to vent the blowby out of the crankcase. Otherwise leaks and consumption of oil past the rings occurs.
Magic?
 
On the stock engine, the "blowback" is sent back to the air intake. There is a short hose from the valve cover to the air intake "mushroom" cap.
That said, the Airsep takes this "blowback" and separates the oil in it so that it can flow back into the crankcase. There is no magic in any of this system, and you could probably make something similar without paying an arm and a leg for it. The crank case is not pressurized unless you plug the hose coming from the valve cover. The valve cover gasket and the oil fill cap must have good gaskets to keep this blowback out of the engine compartment.
 
The Walker A.S sight doesn't explain how the system works, just the wonderful benefits. (Similar to oil additives, all claims, few facts). Well God bless google!

The system does vent to the atmosphere. It has to. However there is a fliter system that requires periodic cleaning. Oil Vapor is collected by means of a .3 micron filter. To reference the filter media size: The fuel filter on my Perkins is a 10 micron. My upstream racor filters to 2 microns. Walker's is again .3mic's...thats tiny. It collects the vapor into droplets which are returned to the crankcase.

I had a small K&N filter breathing the crankcase vent on a XK Jag engine. It managed to coat the entire engine bay with oil mist (but kept the rust in check). So the "magic" in the Walker system is in the shape of the collector and fiter size. Vacuum regulator? No clue!

KEN - What a Perkins also needs is an intake noise silencer system if you ask me. I'd be interested to know if Foley's Walker system does any noise mitigation. Can you let us know about that?
 
The valve cover blow-by hose is routed directly to a separate chamber in the air filter assembly. The air filter is essentially a cylinder laid on its side. The blow-by hose is connected to the top of the cylinder where the vapor is routed through a batting type material - where it coalesces into oil droplets that drain out of the bottom of the cylinder. From there, the now liquid oil drains back to the oil pan via a check valve.

I can't imagine that the batting material is .3 microns. That's tiny. This media looks like the stuffing out of a cheap pillow. Enough to slow the vapor down and allow it to cool. It also provides surface area for droplets to form. I cannot see any way to remove the material to clean it. Perhaps the .3 microns you're referring to is the air filter element.

I have only run the engine for a short time since I installed the system. I motored from the travel lift back to my slip at relatively slow RPM's. It's been several months since I last ran the engine, and I didn't rev the engine much at all. However, if memory serves, I'd say that it does run a little quieter - not enough to claim it as a "feature" of the system.
 
Ken - thanks for the response. Let us know once you start using it more as to the sound.
As far as .3 mic's - I agree. but hey, I read it on the interwebs...it has to be true ????
Dave
 
Dave - I've been doing some more research on the AirSep, and I think I've found the source of the confusion.

Walker does indeed make an AirSep with a .3 micron oil filter; it's called the CCE AirSep and is typically used on some Cummins diesels.

The universal kit recommended for the 4.108 has the batting material - I would hesitate to call it a filter.

Here is a link to a forum where an AirSep tech discusses their product:

http://www.boatered.com/forum/topic.asp?TOPIC_ID=150946
 
An update to my AirSep:

I spent the last 10 days living onboard, and, in my opinion, the noise reduction claim is a bunch of hooey.

The system does seem to help with oil consumption/leaks. I didn't add a drop of oil the entire trip (about 30 hours engine time).
 
So, Ken, after 6 years, what is your conclusion on the AirSep? Still working? How often do you clean or replace the filter material? Thanks.
 
So, Ken, after 6 years, what is your conclusion on the AirSep? Still working? How often do you clean or replace the filter material? Thanks.

Terry - Yes, I'm very happy that I installed the system. I have put about 2000 hours on the engine since I installed it, and, if for no other reason, I feel better having a proper air filter on the engine rather than the original mushroom cap. Blow-by is routed back to the crankcase resulting in a cleaner engine room. Maybe it helped with noise... but I've forgotten what it sounded like before. lol I have replaced the filter once - before our transatlantic last year. It really only needed to be cleaned, but it was cheaper to buy a new filter rather than the cleaning chemicals.
 
I installed one on my Perkins, used it for 2-3 years, maybe 150 hours or so and wasn't impressed. I found the size of it in my engine compartment was not a good tradeoff. There's more to it than just the air filter. I ditched it and went back to the stock air screen/filter. The hope of helping to stem oil leaks as touted by AirSep's literature and elsewhere was a pipe dream... Most of what you get in our engine rooms is belt dust or at least it is in my case and regular cleaning is sufficient. I don't typically operate continuously for long periods of time so cleaning between runs I would think will be fine.... but I have seen Perkins 4-108 engines with oil and belt dust caked inside the filter and thus starves it for air.
 
Thanks for the response. I did note Ken's photos showed a big piece of equipment hung off the back of the engine. Ken, does that make small fuel filter changes even more difficult. I still have the old type, ,which is messy and cumbersome to use. I never figured out how to replace it with a spin on type.
 
Thanks for the response. I did note Ken's photos showed a big piece of equipment hung off the back of the engine. Ken, does that make small fuel filter changes even more difficult. I still have the old type, ,which is messy and cumbersome to use. I never figured out how to replace it with a spin on type.
That "big piece of equipment" is the air filter itself - the dimension might be on the package. I don't think it impedes access to the fuel filter at all. I regularly change the fuel filter. I'd love to replace with a spin on fuel filter, but I think I read on this board that there isn't room in the engine compartment for the adapter. That's why I never went that route.
 
Ken, I have a spin on adapter for the fuel filter and ever since the mechanic that sold it and installed it, I have had intermittent air in fuel problems requiring continuous bleeding of the filter, hydraulic head, top of the IP and then the injectors themselves.... very very frustrating. That was installed in late 2016 if I remember correctly. So I've been dealing with it a long long time. I think this past week while at the boat I figured out the problem... it's not the spin on conversion kit (mine is the Foley version).... the @#$@&!! mechanic left a crush washer off of the banjo fitting on the return line where it mounts at the top of the filter housing and now I believe I know where the source of the air is coming from and why it takes awhile for it to show up....
 
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