Cylinder head oil breather pipe

[William2]

I have modified the oil breather pipe that comes out of the rear of the cylinder head such that it no longer connects to the carb airbox. I have fitted a right angle copper pipe and connected a length of rubber hose that ends just below the chassis cross member. Am I correct in saying that this tube expels air/gas rather than sucking as I have not currently fitted any gauze filter on the end?

[vincereynard]

Out of interest - why? There would be suction in the airbox, although I seem to recall the original twinks were open to atmosphere.

[Foxie]

I have modified the oil breather pipe that comes out of the rear of the cylinder head such that it no longer connects to the carb airbox. I have fitted a right angle copper pipe and connected a length of rubber hose that ends just below the chassis cross member. Am I correct in saying that this tube expels air/gas rather than sucking as I have not currently fitted any gauze filter on the end?

You are correct in saying it blows. More or less, depending on the condition of your piston rings !

However these days it would be considered environmentally friendly to run it to an oil catch tank. I improvised one from a 250ml brake fluid bottle filled with Brillo pads. It sat between the airbox and the pedal box.

[englishmaninwales]

I have modified the oil breather pipe that comes out of the rear of the cylinder head such that it no longer connects to the carb airbox. I have fitted a right angle copper pipe and connected a length of rubber hose that ends just below the chassis cross member. Am I correct in saying that this tube expels air/gas rather than sucking as I have not currently fitted any gauze filter on the end?

This is the standard arrangement on both the S3 Elans I have owned (and probably on S1-2 cars too - it was the arrangement on my father's Mk 1 LC). The 90 elbow is rubber with a steel tube located at its lower end at the gearbox. As above, it blows crankcase gases.

[mbell]

However these days it would be considered environmentally friendly to run it to an oil catch tank. I improvised one from a 250ml brake fluid bottle filled with Brillo pads. It sat between the airbox and the pedal box.

The environmental concern is as much about the fumes exiting the engine block as the mess of the oil. Hence why it's rooted to the engine so the fumes can be burnt on the later standard setup.

Of course that's not great for cylinder number 4 and the system is marginal if the engine isn't in tip top shape.

Personally plan to keep the standard setup but thinking about how to improve it's performance by modifying the out let location in the air box.

[billwill]

The messages and photos in my topic from this point on:
lotus-elan-f19/getting-ogu-roadworthy-again-t26101-75.html#p176701
show my use of standard plumbers parts to modify the breather to use a catch tank.

The catch tank is a cyclists aluminium drinking bottle readily available for ?1 in Poundland etc.

I use a turkey baster with an extension pipe on the front to suck out any collected oil, but so far I have only seen oily water.

[Craven]

Something about a DuckBill in my motorcycling days.