Hey, Just intrested in seeing some of the oil breather catch tanks. What you got any pic? Cheers Craig
I have turned the front washer bottle into a catch tank, and then rear mounted the washer bottle to help with the weight distribution - there is a guide in the styling stickies.
I bought a block off plate for the block and mounted an alloy catch tank to the radiator cowling. It just has some 8AN hosing between the two, makes a funny gurgling noise when the engine's running!
doesnt have to be pretty, heres my temporary effort used for making sure crank emmissions were not causing me any running problems. Note the pipe is not sealed to neck of bottle, there is enough gap to let gasses escape:
I made one out of a mayo jar, seemed appropriate. All it ever caught was dirty brown water though, so I decommissioned it. Now the Hellmann's label has fallen off. [:^(]
i thort if the engine was running ok it wouldnt need a catch tank maybe i dont fully understand why people fit them ,say it was a mk2 16v with the classic blow thru problem and you fit a catch tank to catch the oil so it doesnt go into the air box and up thru the engine,is that what you use one for? and if the engine was performing to standard you woulnt need one as there would be no blow thru,,also to catch water when theres mayo and again the engine shouldnt have mayo if performing to standard am i on the right track here?
by law the engine has to ingest its own fumes, this means the oil vapour that is given off when the oil gets hot. The mass of the crank moving around near the sump and the higher temps within the crank case vs atmos means that the oil vapour is forced out fo the engine (if there was no breather it would make a big build up of pressure untill a seal gave way). the oil and water vapour (ill come to that) reduce the RON rating of the fuel and thus reduce power, with the oil vapour removed the burn is cleaner and purer and therefore the timing can be tweaked a little to give even more power (its also helps with ecconomy as more power = less throttle needed for steady crusing). Also on diesels it stops the intercooler being coated in oil reducing its efficency, it also stops the EGR gummying up and the inlets as the small amount of soot in the egr now has no hot oil to mix with to make gunge. and when tdi comes on boost it sucks very hard and can suck excess oil from the crank case). It also collects mayo when its cold. thsi is due to the fact that when an engines stod is its not a closed system, air and moisture can and will get into the oil system via the breathers, as the engine cools its creates a slight neg pressure relative to outside to actually sucks air in. this air has moisture in it. when the engines started and gets warm the water evaporates and leaves via the breathers, when it reaches the catch can it condenses again and mixes with oil in the catch can to make mayo. The more worn the rings and the harder the car is driven the more oil will be sent out via the breathers due to the crank case being pressureised more if the rings are a little worn and allowing a small amount of blow-by, and a harder driven car will be sucking harder so will again draw more vapour from the crank case. I hope this makes sense lol, as Ive prob written it all crap.
Good work M7R. When you blow a piston its good to have a catch tank ! Mayo everywhere !! Right Hand Side of Pic
cheers,i understand about the crank fumes and the fact it has to e reburned,also if the rings are worn theres more pessure that eventualy will force oil thru not just the vapor ,so if i read that correctly the engine burns cleaner without the crank fumes even tho an engine runs ok it still creates moisture so really a catch tank would be a good thing to fit then,regardless of engine condition,,so why didnt vw fit one in the first place
extra expense basically, the engine will run just fine injesting a bit of oil n moisture from the breather so why bother fitting one at the factory. over a period of time it can build up a solid caking of crud in the airbox/inlet, which needs to be cleaned out. with a catch tank this problem is reduced or solved completly if the fumes are vented to air
