Hi, I have a 1975 Escort Mk1 and need to know how the crankcase ventilation is plumbed. At the moment the previous owner   run 2 long pipes to the rear of the car. The motor is a bit fummy but this is not helping. I plan to fit a better motor when I find one but I am trying to get things back to how they should be. Thanks Peter.

Into the intake manifold. Make sure there's a PCV valve in the oil separator and check that it works. (give it a shake and listen for the rattle)

Ok, so you mean from the breather on the side to the intake, not under the air filter. Also the motor is a mixture of parts what type of breather should the rocker cover have. It has a 691 block, I will be changing this later.

Yes that's what I mean.
Earlier escorts had a rocker cover breather cap with no barb for hose take off. If yours has the barb then take a hose to the bottom of air cleaner.

Thanks for that, I will be doing the job tomorrow. I will have to find a T piece for the intake, it has a single barb at the moment.

That's the go. There was a T fitted in the manifolds from factory so you're on the right track. Good luck with it. It will be a lot better without the fumes

All done, thanks for all the help. I have a Mk2 van thats a bit of a stalled project so I robbed the part from it. The valve needed changing also, the guts had been removed. There was 2 lengths of garden hose running from the valve and breather cap to the rear spring. It had been there a long time . I will need to replace a lot of parts on the Mk2 later, to convenient. 

Did some reading on PCV's, on wiki the following, which seems to describe what you had, this appears to be ath solution before the PCV, which apparently was one of the first so called "smog" controlls-

Road draft tube[edit]

The first refinement in crankcase ventilation was the road draft tube, which is a pipe running from a high location contiguous to the crankcase (such as the side of the engine block, or the valve cover on an overhead valve engine) down to an open end facing down and located in the vehicle's slipstream. When the vehicle is moving, airflow across the open end of the tube creates a draft that pulls gases out of the crankcase. The high location of the engine end of the pipe minimises liquid oil loss. An air inlet path to the crankcase, called the breather and often incorporated into the oil filler cap, meant that when a draft was generated at the tube, fresh air swept through the crankcase to clear out the blow-by gases.[2]
The road draft tube, though simple, has shortcomings: it does not function when the vehicle is moving too slowly to create a draft, so postal and other slow-moving delivery vehicles tended to suffer rapid buildup of engine sludge due to poor crankcase ventilation. And non-road vehicles such as boats never generated a draft on the tube, no matter how fast they were going.[2] The draft tube discharged the crankcase gases, composed largely of unburnt hydrocarbons, directly into the air. This created pollution as well as objectionable odors.[2] Moreover, the draft tube could become clogged with snow or ice, in which case crankcase pressure would build and cause oil leaks and gasket failure.[3]

Interesting read, with my car they took the breather back as well stopping the flow. They also didn't take it back far enough and the fumes come in the rear doors, also helped by the doors not fitting right. Now I have got the issue of the motor running on, must have some carbon buildup.

It makes some good points-
 
Deleting the charchol canister-
Blocking off or leaving your crank case or rocker cover vent open-
 
Results in-
 
For blocked off vents-
"case crankcase pressure would build and cause oil leaks and gasket failure"
"tended to suffer rapid buildup of engine sludge due to poor crankcase ventilation"
 
For open vents-
"crankcase gases, composed largely of unburnt hydrocarbons, directly into the air"
________________________________________________________________________________________
 
More information on charchol canisters here-
 
Taken from rennlist.com forum- Edited a little, to make it easier to read. The purpose of this information gathering was to make sure all the conditions for tuning my 32/36 Weber DGV 5A carburettor were met. I want to do a more comprehensive tuning guide for it. One of the conditions was to ensure that you are using so called "ported" vacuums, or understand why you are not.
 
Flushing air to the charcoal canister is supplied from the air cleaner.
 
Fuel vapors only accumulate in the charcoal canister when the engine is off. The tank is always vented through the charcoal canister regardless of engine on or off. When the engine is off the pressure from evaporating fuel in the tank escapes through the charchol canister and into the air cleaner housing. The charcoal captures the fuel vapor when this flow occurs. When the engine is on air is drawn through the fuel tank and through the charcoal canister via engine vacuum to draw the accumulated fuel vapors in the canister and any new vapor in the fuel tank into the intake manifold to be burned in the engine.
 
The purge valve vacuum port on the throttle body is on the air cleaner side of the throttle plate. When the throttle plate is closed there is low vacuum at the port. As the throttle opens above idle, vacuum is applied to the purge valve. As the throttle opens wider toward wide open, manifold vacuum drops and there isn't enough to keep the purge valve open so it shuts.
(The purge valve doesnt appear to be on older cars like the Ford Escort XFlow or Kent motor, the tubes run from the tank to the inlet on the charchol canister, from the charchol canister to vacuum on the carb or inlet manifold, from the charchol canister to the air cleaner. Thetake away from this paragraph is "The vacuum port is taken from the air cleaner side of the throttle body" )
(N.B The only reason I can give as to why the "ported" vacuum is required on a XFlow with a carb is to ensure idol tuning is done corectly, ported air becomes part of the tuning curcit, un-ported air will change your air / fuel ratio bypassing tuning and inconsistantly at that!)
 
 
The charcoal canister does allow flow in either direction. However, flow is dependent on a difference in pressure. Hence, when manifold vacuum is applied to the canister via the open purge valve flow is from the air cleaner through the canister to the manifold. When the purge valve is shut flow only occurs when fuel vapor pressure in the tank is greater than atmospheric pressure and then flow is from the tank through the canister and then to the air cleaner housing to atmosphere.

With the cost of fuel these days it makes sense to me to retain, capture, and burn every drop I paid for. The charcoal canisters rarely go bad so you are left with a couple of valves, some fuel vapor line, and some vacuum line to replace to ensure the system works as designed. It really is a pretty simple, elegant solution to reducing fuel vapor emissions.

Hope this helps."
 
I have collected information on other systems relevant to setting up a carb on a xflow, does this need a dedicated thread on charchol canisters?
 
GMU..