Oil catch tank

[DerekJ]

My catch tank vents to atmosphere via a filter. Why would you want to direct this stuff back into the intake system?

 

[Bob_Spidell]

My catch tank vents to atmosphere via a filter. Why would you want to direct this stuff back into the intake system?

I'll bite: So you're not dumping it into the air we all breathe (why engines went from 'road draft' tubes, to carburettor tubes to PCV systems; most cars still use PCVs, for the same reason). It's generally agreed that combusting blow-by gasses is at least marginally less harmful than dumping them into the atmosphere (which may be true only if you have a catalytic converter, but the thought counts).

I think, ideally, you have an 'oil-air separator'--i.e. a catch can--and a PCV. I put a separator on my Mustang GT, it traps about a teaspoon of oil every thousand miles.

 

[andrea]

Low cost Chinese tank easy to control and unload in a NOT invasive position
https://photos.app.goo.gl/9TrxtMQWv3kNFs2s9

 

[steveg]

Not only is Adrea's easy to empty, it has a sight glass to see whether it even needs to be emptied!

The Ducati Diana has a built-in recycling road draft tube - reaching from the engine to the tail light. This allows vapor to condense and run back into the engine.

 

[steveg]

Does anyone know the actual name of this type of clamp?

Found it: "hose separator clamp"

 

[andrea]

59040[/ATTACH]

Hi Steve
Long time ago I have one similar to this 175 cc model DUCATI "CALIFORNIA" because have the seat fringed as Western and a knees protection with two chromed clack sons a poor imitation of Americans Motorcycles- but a strong and reliable motorbike

 

[mgtf328]

Andrea, RAC68 suggested in a previous post that the can should be mounted high enough to avoid the possibility of initiating a syphoning effect. I can't personally see how you could drain the sump this way but I was wondering whether you took any precautions and what your experience is mounting the can so low.
AJ

 

[John Turney]

Andrea, RAC68 suggested in a previous post that the can should be mounted high enough to avoid the possibility of initiating a syphoning effect. I can't personally see how you could drain the sump this way but I was wondering whether you took any precautions and what your experience is mounting the can so low.
AJ

If the can is connected to the T at the top of the valve cover, one won't get syphoning. If the can is connected to the vertical pipe from the side cover to the T, much more oil will be collected in the can. One of my experiments showed that.

 

[Lin]

John,
So, what did you do for pressure relief and venting of the rocker cover?
Lin

 

[John Turney]

John,
So, what did you do for pressure relief and venting of the rocker cover?
Lin

Hi Lin,

That was one of my PCV experiments. Most PCV valve installations, including my early one, don't have a filtered air inlet.

So, I put a small vent filter on one leg of the T atop the rocker cover with an orifice behind it for an air inlet. The other horizontal leg of the T was blocked, so that air would enter the T, go into the rocker cover, down around the push rods to the crankcase. I had a hose off the vertical pipe that normally goes from the side cover to the T that went to the oil catch tank and then to the PCV valve.

Anyway, the catch tank collected a lot of oil, so that idea was abandoned.

 

[andrea]

Hi MGTF
I considered that the air filter on the TOP of the can catch tank can avoid the siphon problems -that can appear only in presence of LIQUID VACUUM in the OIL circulation - Engine OIL level are lower - and on the pipe we have only oil vapors that then condenses in the catch
However your observation can be correct , and I seriously consider the add of a little air inlet valve near the top T joint -
BUT catch can was applied some Years ago and no siphon problems was observed during this time

 

[Deleted member 21878]

i added the filter at the side cover/verticle vent pipe. my verticle vent pipe is plugged so nothing gets pulled thru it. the side cover now just lets air in. all the vaccum comes out the valve cover. it is my understanding that allowing fresh filtered air into an engine is a good thing for the metal parts and the oil.
To control the amount of air and also the amount of vaccum inside the engine, i bought a small paint gun valve from HF. then i hooked up my system and ran the car. i turned the valve control to get the vacuum to no more than 1" of hg. probably should even be less but hard to get a good reading below that. when i changed the oil last time, i could hear air being pulled thru the filter while draining the oil.
after the valve was set, i watch the reading over various RPM's. the reading of 1" never changed.

if you look closely you can see the filter down in the right bottom corner of the pic. it is kind of hidden behind the frame.

 

[Bob_Spidell]

FWIW, in normally-aspirated aircraft--with both manifold pressure and ambient air pressure readings available--engines always pull at least 1" of Hg negative air pressure (i.e. 'vacuum'), even at WOT. Some highly-tuned engines may be less, but a 1" pressure loss in the manifold and throttle is pretty much a truism.