Al2O3 said:

When an engine's piston rings and cylinder bores are worn you can get combustion gasses getting past the rings and in to the crankcase. The crankcase is the bottom part of the engine where all of the oil returns to, the crankshaft is spinning around in here connected to the pistons. This gas pressurises the crankcase and this pressure also makes it's way up through the cylinder head and in to the rocker cover - this is the aluminium top of the engine that has the yellow oil filler cap on it. This escaping combustion gas is known as 'blow by' and your engine is said to be 'breathing heavily' when this pressure is chuffing out of the oil filler cap hole when the engine is running. If your engine isn't doing the chuffing thing, then that is good news.
Even when a healthy engine is running normally there is a certain amount of pressure created, air in the sump gets hot and expands, the oil gets hot and you have pistons thrashing up and down causing displacement within the crankcase. There is a pipe from the rocker cover that goes to your air inlet pipe to relieve this small amount of pressure. With all of the heat and your crankshaft, pistons etc thrashing about, some of the oil gets atomised and creates an oily vapour. To stop this oil being carried through that vent pipe and in to your air intake, they have put in the cyclone breather to centrifuge that oil out. Any oil 'spun' out (condensed) drops out through the bottom of the cyclone via a pipe on the bottom and trickles down to join the rest of the oil in the sump.
If your engine is ok then the amount of pressure created is small and the amount of oil the cyclone has to remove is also small. As has been said above, some people just allow the vent pipe to vent to atmosphere and they plug the hole in the air induction pipe. Some people put the end of the pipe in to a 'catch can' to collect any oil that might make it through. I did the catch can thing with mine once and ran it like that for a while and got absolutely nothing in the catch can.
It's highly unlikely that you need to change your cyclone breather.

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Dub Siren said:

Thanks everyone! So I do think I have a 110 not a 90.

Given that the Dow pipe is in place I seemingly just need a mid and rear section for a 200or300tdi as that’s the engine which is now fitted.

Obviously there were no 300tdi engines in 1985 so I suppose I go for the earliest 200tdi exhaust for a 110? Suppose 110 is a measurement for chassis so pretty much all the same size and important thing is I match the right exhaust to the engine?

Thanks again!!

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v8250 said:

Oops, me bad, yes definitely a OneTen. Yes to a 300Tdi 110 exhaust system. The exhaust hanger mounts are near the same locations...what you may have to do to fit well is to rotate the hanger plates. It's worth offering up the complete exhaust loosely onto the hanger/mounts, then adjust and work front to rear tightening up.

Note: if there's a slight diameter size difference between old and new exhaust pipe, slit cut one end open up to ~50mm to allow a good fit and clamp down.

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Al2O3 said:

When an engine's piston rings and cylinder bores are worn you can get combustion gasses getting past the rings and in to the crankcase. The crankcase is the bottom part of the engine where all of the oil returns to, the crankshaft is spinning around in here connected to the pistons. This gas pressurises the crankcase and this pressure also makes it's way up through the cylinder head and in to the rocker cover - this is the aluminium top of the engine that has the yellow oil filler cap on it. This escaping combustion gas is known as 'blow by' and your engine is said to be 'breathing heavily' when this pressure is chuffing out of the oil filler cap hole when the engine is running. If your engine isn't doing the chuffing thing, then that is good news.
Even when a healthy engine is running normally there is a certain amount of pressure created, air in the sump gets hot and expands, the oil gets hot and you have pistons thrashing up and down causing displacement within the crankcase. There is a pipe from the rocker cover that goes to your air inlet pipe to relieve this small amount of pressure. With all of the heat and your crankshaft, pistons etc thrashing about, some of the oil gets atomised and creates an oily vapour. To stop this oil being carried through that vent pipe and in to your air intake, they have put in the cyclone breather to centrifuge that oil out. Any oil 'spun' out (condensed) drops out through the bottom of the cyclone via a pipe on the bottom and trickles down to join the rest of the oil in the sump.
If your engine is ok then the amount of pressure created is small and the amount of oil the cyclone has to remove is also small. As has been said above, some people just allow the vent pipe to vent to atmosphere and they plug the hole in the air induction pipe. Some people put the end of the pipe in to a 'catch can' to collect any oil that might make it through. I did the catch can thing with mine once and ran it like that for a while and got absolutely nothing in the catch can.
It's highly unlikely that you need to change your cyclone breather.

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KISSMYAURA said:

i had a spitfire once that used to fire the dipstick and some oil a good 10 feet in the air due to blow by lol. it was lashed down with bendy wire used to hop about like a lid on a pot. and before you ask yes the engine lasted about a month like than then shat itself and stopped for good.

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KISSMYAURA said:

i had a spitfire once that used to fire the dipstick and some oil a good 10 feet in the air due to blow by lol. it was lashed down with bendy wire used to hop about like a lid on a pot. and before you ask yes the engine lasted about a month like than then shat itself and stopped for good.

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KISSMYAURA said:

i had a spitfire once that used to fire the dipstick and some oil a good 10 feet in the air due to blow by lol. it was lashed down with bendy wire used to hop about like a lid on a pot. and before you ask yes the engine lasted about a month like than then shat itself and stopped for good.

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Al2O3 said:

Classic Back in those days engines seemed to managed about 70K and then were knackered. Tastiest I had back then was a Mini 1275GT. Loved it Had the engine out of that a couple of times sorting the idler gear out. I remember heating the casing up on my mother's gas cooker to help knock the bearing out. Happy days

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tottot said:

Spitfire and it's ability for the boot to pass one, if you did not catch it on the first twitch you were gone.
Dolomite was much the same but I still loved mine.

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