Catch Cans

[AustHaflinger]

My Haflinger was built in 1973 so should have all the later changes to the engine that were made over the years but it doesn't.

The case is the correct crankcase but it has a number of older features like a No5 cam shaft, the early oil filter, the early oil filler and crankcase ventilation system. I believe that in the past the engine has had some sort of major failure and was rebuilt with lots of bits from another much older engine (which I have the remains of in my spares bin).

Putting aside major parts such as the crankshaft and camshaft one of the things I do not like is the crankcase ventilation is the old style - just a pipe from the oil filler cap down through the floor of the engine bay. Is OK at lower revs but when the engine has working hard the oil mist from the crankcase collects in the dump pipe and then drips onto the ground for quite a while after the engine stops. In the modern engine the crankcase ventilation pipe is routed to the airfilter housing where the oil mist is sucked into the carb and burnt in the engine. Problems with with system is that the oil mist can condense in the aircleaner making a mess or adding to carbon build up in the engine.

The way many modern vehicles deal with this is to have a catch can between the crankcase ventilation system and the inlet suction from the air cleaner. The catch can catches the oil mist while allowing the excess air from the crankcase (now free of oil) to go back into the engine.

So after that long bit of background, has anyone put a catch can on their engine and if so how have you found it.

Garry

[heinkeljb]

Not done anything like that on the haf, but someone in one of the Smart car forums I frequent has put a Landrover one on his Smart and says it works well. Then he built his own one from bits of copper tubing as the Landrover one was a bit too big and difficult to fit in the engine bay on a Smart.
I'll see if I can find the post and "borrow" some pictures, etc.

On My Haf with the Oil breather connected to the Carb, there is a one way valve in the top cap with a little bore ~ 5mm pipe going to the Carb, but it connects to the carb after the air filter so does not coat the air filter with an oil layer.

The simplest version I can think of for a Haf, would be a tin with a screw lid into which you put two pipes. One would take the pipe from the oil filler tube,, the other would have a little air filter on it just so it can catch the oil in the mist as lt tries to leave the can.
The can could live strapped to the oil filler tube.

John

[AustHaflinger]

On My Haf with the Oil breather connected to the Carb, there is a one way valve in the top cap with a little bore ~ 5mm pipe going to the Carb, but it connects to the carb after the air filter so does not coat the air filter with an oil layer.

Thanks John - on yours does it connect to the carb or the air intake housing above the carb like this one?

Basic small catch cans can be bought on ebay very cheaply. Here is one cheap example
https://www.ebay.com.au/itm/Universal-B ... :rk:1:pf:0

Cheers

Garry

[heinkeljb]

As far as I know they all connect like your picture.

The clear catch can might be a better bet just because you can see when it’s full - The other sort you would always be opening it “ just in case” it was full.....

John

[Julian B]

As far as I know they all connect like your picture.

No - early ones (like mine) have a vent through a rubber tube that goes directly down & through the tin floor. Not sure when the change happened, but possibly when they changed from Weber to Zenith carbs?

[Julian B]

In a 1960 parts manual (green arrow) you can see the short stubby tube of metal in the right hand side "floor" that the rubber vent pipe attaches to, but on a later one (red arrow) that piece is not shown.

[heinkeljb]

Sorry, my statement was meant to mean that “alll those with the little vent pipe at the top of the oil filler pipe” would be connected the same way as the picture. I agree that earlier engines did not have the vent tube to the Carb but blew the fumes out under the engine leading, as Gary points out, to drip marks on the floor after you finish driving.

Engine and running gear appear to be some of the few things on a Haf that are the same between individual machines!

John

[AustHaflinger]

Yes my current arrangement is as per Julian's pic etc - I am sure a 73 model should not have that style.

I bought some stainless steel kitchen scourers and put them in the top of the of the oil filler - made a big improvement and really catches the oil to flow back into sump without restricting gas flow but not quite enough.