Crankcase vent hose

[ecohen2]

Random question...

Has anyone added a oil catch can or changed the routing of the oil crankcase vent hose? I noticed that I am getting enough blow by that the inside of my intake manifold is pretty greasy. It seems like it would be easy to route that hose to a can mounted on the firewall and then either vent it or feed it back into the large rubber intake hose...

Ed

 

[toddr124]

On my spider I added a lawn mower air filter. Caught about 90% of the oil.

 

[ecohen2]

So the question is: Is it better to put a catch can inline or get one that has a filter and vents to the atmosphere?

 

[Ernie]

Last year I put a catch can on my 128sl because I wasn't sure if I would pass the tech inspection at an autocross. Every time I pulled up to a light or stop sign it looked like my radiator was steaming. Never saw that when it was vented to ground and never saw it in any of my 124 spiders vented to ground.

All my cars would occasionally drop a spot of oil from the tube, but nothing worrisome at all.

 

[lookforjoe]

So the question is: Is it better to put a catch can inline or get one that has a filter and vents to the atmosphere?

Depends on how much you like to inhale crankcase stank

If you have significant blowby, and it's not because the box/cyclonic trap are clogged (which will push oil out due to CC pressure), you probably have a engine tear down in your future.

Assuming you've cleaned out all the stock breather components, including the trap placed inside the longer section of tube,

adding a catch can should be done using only fittings/ports that are equal or greater OD than the stock ports. Most generic cans are crap & fittings are way to small. A good can will be baffled to separate the water/oil condensate for draining, allowing only the air to pass on.

 

[ecohen2]

WAIT! There is a trap? I need to find this and clean it out...

From what I saw, I just had two rubber hoses that feed into the giant intake rubber hose... Ill take a closer look this afternoon and see what else I find... Thanks!

 

[lookforjoe]

WAIT! There is a trap? I need to find this and clean it out...

From what I saw, I just had two rubber hoses that feed into the giant intake rubber hose... Ill take a closer look this afternoon and see what else I find... Thanks!

Layout should be: breather box>long hose (with trap inside) plastic nipple/control vac tube>short hose>ribbed inlet hose

 

[paynebabes]

I've got a catch can. Baffled can which then vents to atmosphere. If you have a lot of blowby it can be the fuel pump leaking into the sump.
.

 

[ecohen2]

So I went and looked everywhere for a box or anything that looked like it could hold a baffle of some sort and couldn't find anything. I have a very loose, soft hose that goes from the crank case to this little T connector. The connector is kind of restrictive but clearly would let fluid pass by. Here are images of the connector... It is empty on the inside... I wonder if this is true for all of the Bertones?

 

[aarpcard]

So I went and looked everywhere for a box or anything that looked like it could hold a baffle of some sort and couldn't find anything. I have a very loose, soft hose that goes from the crank case to this little T connector. The connector is kind of restrictive but clearly would let fluid pass by. Here are images of the connector... It is empty on the inside... I wonder if this is true for all of the Bertones?

What year is your Bertone? The t-connector on mine ('84) looks very different. Definitely big enough to have a trap inside.

 

[kmead]

So I went and looked everywhere for a box or anything that looked like it could hold a baffle of some sort and couldn't find anything. I have a very loose, soft hose that goes from the crank case to this little T connector. The connector is kind of restrictive but clearly would let fluid pass by. Here are images of the connector... It is empty on the inside... I wonder if this is true for all of the Bertones?

The hose with the plastic T attaches to is the cyclonic trap, all Fiats use a similar solution and looks like this:

The flame trap lives in the hose going from the cyclonic trap shown above that is attached to the block, just below the plastic T you have in your picture.

If you add an additional catch system given that you have a fuel injected car, it should be airtight so it doesn’t induce an additional vacuum leak or vent to atmosphere.

So is it really a big deal if your intake has oil residue in it? Either way it is hydrocarbons that are being burned and in general there isn’t anything in there that will be damaged by some oil.

 

[ecohen2]

I don't have anything that even looks remotely like that... The little T hose connects to the intake plenum right next to the cold start injector. I am going to keep an eye on the intake manifold and how much oil accumulates. None of the oil looked recent so it could have been from a long time ago...

Ed

 

[kmead]

The casting shown above is mounted to the engine block and is what your hose is attached to. It’s hard to see from above.

 

[carl]

Ed, as noted by Kmead, that casting is on the block and your vent hose attaches to it. Similar as to what's on my spider. If we hook up Saturday I'll point it out to you.

 

[MikeHynes]

I've added a catch can on a racecar by simply connecting a long transparent hose to the cyclonic trap and running it to an old antifreeze container set into the "well" of the trunk. The antifreeze container is cheap (free), will hold much more blow-by than you'll ever see, allows you to monitor just how much blow by you're getting, and the hose fits to the container well. I use a second antifreeze container to vent the trans. They fit pretty securely. You may never need a catch-can for your trans - just don't drive though any deep water.

 

[lookforjoe]

You can see the lower hose section that houses the screen/trap below the plastic nipple I illustrated in this pic of mine with the head off... that hose fits over the breather box / cyclonic trap Karl posted the epic of.

 

[dcioccarelli]

Random question...

Has anyone added a oil catch can or changed the routing of the oil crankcase vent hose? I noticed that I am getting enough blow by that the inside of my intake manifold is pretty greasy. It seems like it would be easy to route that hose to a can mounted on the firewall and then either vent it or feed it back into the large rubber intake hose...

Ed

I did exactly this a coupe of years ago. I had an issue where (randomly) I'd be getting junk in my carburettor jets and, upon closer inspection, it appeared to be carbon deposits from the engine. I mounted a catch can where the charcoal canister used to reside and routed the crankcase vent via that. No more problems subsequently. Note that did have a flame trap in place and clean cyclonic trap but nevertheless I was getting intermittent carbon flakes blocking the jets. That said, I do have 250K KMs on the car, so there is some blowby.

I'll take some photos of my setup later.

Cheers,
Dom.

 

[Eastep]

So the question is: Is it better to put a catch can inline or get one that has a filter and vents to the atmosphere?

Vents to atmosphere, is best for the car, but worse for the environment. My vent tube has a small "pod" filter slipped over it.

 

[dcioccarelli]

I did exactly this a coupe of years ago. I had an issue where (randomly) I'd be getting junk in my carburettor jets and, upon closer inspection, it appeared to be carbon deposits from the engine. I mounted a catch can where the charcoal canister used to reside and routed the crankcase vent via that. No more problems subsequently. Note that did have a flame trap in place and clean cyclonic trap but nevertheless I was getting intermittent carbon flakes blocking the jets. That said, I do have 250K KMs on the car, so there is some blowby.

I'll take some photos of my setup later.

Cheers,
Dom.

Here are some photos:

 

[ashmowerman]

I will throw my 5 cents in.
this is my Mann + Hummel catch tank with oil return to sump.