Perkins 4.108 'Puke Bottle' Breather Tube

[jlogan]

I´m a long time subscriber to Boatdiesel, so I am very familiar with the common practice of running a "puke bottle" to handle the condensed oil/water gunk from the breather on the Cummins B - did that on the last 210hp B I owned.

I now have a 4.108 Perkins in 37ft Gulfstar - runs fine, only put about 30-50 hours per year on it, I´ve rebuilt everything on it and gone through all the cooling and fuel systems Engine seems tight and doesn´t smoke or have any leak issues.

Point is, the 4.108 marine version doesn´t really have an air filter - just something that would stop a house fly, but wouldn´t stop a mosquito - just 1/16 in holes - so I fitted a K&N air filter to the intake -

In removing the stock "bug strainer" - you also remove the place to put the breather hose from the valve cover - it just terminated "close to" the bug strainer, so engine vacuum pulled the vapor into the engine...poor man´s egr, I guess.

So when I put the K&N filter on, I just took some suitable hose, attached it to the breather tube coming off the valve cover, and ran it down to an old Valvoline 10-40 1 gal container...instant overflow bottle.

I´ve run this a few hours, and it seems to work ok, but I thought I would check this out with the folks on this board - what ya think? Should I find some sort of metal bottle or container for this?

Anybody done anything like this and have experience?

Comments appreciated.

[SV Demeter]

I think you will be venting your crankcase to your engine compartment. There is a reason that hose was routed to the intake, poor mans EGR is spot on. What was wrong with the OEM setup? Was it giving you some sort of problem?

[btrayfors]

One problem with the original setup is it can lead to a filthy engine room.

I put a Walker AirSep on my 4-108 a few years back, and am tickled pink by the results. No more messy engine room and at least I feel better because the engine has a fairly decent air filter :-)

Not the cheapest solution, but it works very well...probably because it creates negative crankcase pressure as well.

Bill

[jlogan]

The reason for the change was that the Perkins has no air filter, wanted an air filter for a number of reasons to include increased engine life and less noise from the intake...seems to do that.

While it is true the bottle vents to the engine room, the 3 foot length of hose sloping downward toward the collection bottle lets vapor condense - there is no visible smoke or vapor coming from the mouth of the bottle in operation, I put a little filter material where the hose enters the bottle to stop this, but so far, nothing. The engine is in good shape with no evident blow-by into the valve cover, so I don't seem to have any oil vapor problem so far. This would not work on a worn-out high blowby engine that smokes, in my opinion.

[CSY Man]

I put a Walker AirSep on my 4-108 a few years back, and am tickled pink by the results

so I fitted a K&N air filter to the intake -

Would like to see pics/specs of the above set-ups.
Been looking for air filter or air-box for my 4-108 for a while, not only to baby the engine, but also for noise and clean(er) engine.

As for hose and puke bottle, got that on the cooling system:
The engine would sometimes burb a little coolant and it would get green and messy on the oil-blanket under the engine.
The hose and bottle collects it and I pour it back in the tank every few months or so, perfect solution, money wise and recycling and all.

[btrayfors]

Originally Posted by CSY Man

Would like to see pics/specs of the above set-ups.
Been looking for air filter or air-box for my 4-108 for a while, not only to baby the engine, but also for noise and clean(er) engine.

...

Here you go: AirSep_0135

Bill

[jlogan]

The Walker Air-Sep on the Perkins is definitely the way to go if you have the bucks, I am somewhat more "thrifty" and mechanically inclined, so I went with a K&N filter for about $30.00 - I used one of the Universal fit sort, with a 2 1/4 inch opening and hose clamp ( I think, need to measure that before you buy) and plastic ends to have less of a corrosion problem. Took off the old "air cleaner", clamped the K&N to the intake stub, ran the hose from the valve cover to the bottle, and I was done...$30 for filter, 3 ft of hose at $1.19 per foot, scrap oil bottle and foam filter material, and 10 minutes.

I have seen this done where a fitting was installed to the end of the filter with epoxy and the breather tube run into the filter through that fitting. I might try this if I could be sure of the fitting and such not coming loose. I am not a fan of loose parts trying to find a way through the engine when they loosen over time, which they will.

I have also seen this on this forum, I think, where someone made up a piece of 2 1/4 exhaust pipe with a brazed piece of pipe on the side that was 5/8" o.d. for the hose from the breather and clamped that to the intake flange and the filter to the other end of the pipe. This is a much neater solution, but does require a little cutting and welding...probably a muffler shop could make this up for you. A paint job would help with corrosion. I'll do this when I have time.

Just FYI....until around 1965 or so, just about every automobile in the United States had valve cover breathers that vented directly to the atmosphere. a motor in good shape doesn't pass much gas or vapor out a valve cover vent. It does vent some, hence EPA regulations stopped the practice.

I'll send pictures next time I am on the boat.

[chrisjs]

My Cummins 6BTA5.9 (280HP) does not dribble but does put out a little oil vapor over the course of the season. The solution is simple and (almost) free!
The crankcase breather outlet tube is fitted into the neck of a 1 gallon plastic container, like a cleaned oil or antifreeze jug. A slit in the side of the jug enables it to be stuffed loosely with paper towel that effectively condenses and "filters" out the discharged oil vapor. You can either seal the slit with tape or just leave it open to the atmosphere, but do not seal the container top which must still be open to allow the original function of the engine breather tube. Once a season or so replace the jug with a clean one or just replace the paper towels. After a 100 hours or so, the paper towels are stained light yellow close to the outlet tube, but are dry. Works just fine for me without any expense or additional plumbing!! There are plenty of other items to spend money on!!