engine breather pipe

Read the blog about the breather pipes on the engines, and as a matter of interest and info I have 1968/9 2000 TC engine waiting to go into my 2200 auto car, I have fitted a chrome covered gauze breather direct onto the breather outlet nipple at the front of the engine ( so no pipes or flame trap).I have done this as unlike the 2200 engine there is not any connection for the breather hose on the carb or the twin carb air filter.Can anybody see a downside if so I will just drill a hole into the air filter and run the breather hose to it.

John :lol:


Active Member
Looking at my '75 2200TC, the front engine breather pipe goes into a y-connector and the two ends then go to crankcase ventillation ports on each carb. I suspect that the breather connection via the carb's is effectivley eliminating the need for a Positive Crankcase Ventillation (PCV) valve. If you connect directly to the air cleaner you might want to consider fitting a PCV valve to stop "blow-by" gases from the crankshaft being drawn back into the crankcase?

What is the standard setup on earlier 2000sc/tc engines (i.e. what is the front engine breather normally connected to)?

Simple overview of positive crankcase ventilation:-

Really good in-depth explanation of crankcase ventillation hstory and mention of SU carb's replacing need for PCV valves:-

Some useful info from MGA forum:-
On a 2000sc the breather pipe runs from the dome on top of the rocker cover to the back of the air filter. The dome has a gauze filter, but Ive never noticed a valve in there
The 2200sc engine has a crank breather from the front of the engine via a flame trap directly into a connection on the carb.There is also a vent pipe from the dome on the rocker cover to the air filter.

the 2000tc engine that I have has no connections on the carbs or air filter so hence the idea of a open vented system with a nice chrome gauze fitted at the same nipple on the front of the engine.



Active Member
On a 2000sc the breather pipe runs from the dome on top of the rocker cover to the back of the air filter. The dome has a gauze filter, but Ive never noticed a valve in there
Thanks. On my '75 2200TC, there is just a single hose from the dome on the rocker cover to the air filter housing.

John, if you have a rocker "dome" with two connections like alfesti's, maybe you could connect the breather outlet via the dome onto the air cleaner to recreate a more authentic setup?
I have just looked at the 2000TC engine in my workshop,and the rocker vent cap has NO outlet pipes to go to the carb, so the only vent is the one at the front of the engine so as there are No fittings on the carb or inlet manifold to accept a vent pipe I can only assume that this engine vented to atmosphere. The only nipple is on the inlet manifold to accept the servo hose, possibly a banjo could be fitted there if a suitable one is available.

That pic is of a very early engine. (pre '66 I think) They had a filtered breather mounted to the side of the sump which you can just see behind the engine mount and no pipe from the front of the engine. If your engine has a rocker cover breather with no pipes, it is the wrong one.
The '66 to '68 engines had the same flat type of cap but with two pipes (like mine) and then from '69 on the cap changed to a rounder type with 3 indents on the sides and one pipe that went to the air cleaner side of the rear carb. The pipe on the front of the engine then went (via flame trap) to fittings on the manifold side of both carbs.

WAIT!!! :oops: I just found a picture in James Taylor's book that shows a very early TC motor with no breather pipes from the rocker cover and a piece of pipe coming off the front of the motor that goes up briefly then loops around and disappears downwards and out of sight below the fuel pump. I'm not sure where this goes, maybe simply to atmosphere or maybe the sump mounted breather is still present. Either way, i'm fairly certain that this arrangement would have only been appropriate for the earliest of TCs. I can't find any other pictures at this point I'm afraid but I'll keep looking.
OK, I found a picture. This is from a very early 2000TC brochure, no dates but it lists Wedgewood blue as a colour so definitely pre mid '66.

Looks like the pipe just vents to atmosphere but it also looks like this motor still has the sump mounted breather too (Possibly. Very hard to make out, could be a blanking plate)
I guess it's up to you. You could stick with the open crankcase setup that you have if it's all there, but if you want to be pedantic and make the engine 'correct' for your car's year, then you could track down the right venty bits.
Thanks for the extra pics, trying and be a little pc I wil run the breather pipe around to the air filter and connect their so as to reseculate the gases.also swap to the later type rocker breather.going by the engine number my unit a is a 68/69

My apologies for resurrecting a (VERY!) old thread, but I wanted to chime in that I have an early 1966 NADA 2000TC that has the system in the photo posted above by @KiwiRover. It has the flat cap on the valve cover and a draft tube connected via a rubber elbow to the RH front of the engine. If anyone wants more details and photos, please let me know.

Rather than hijack this thread, I posted up a new thread here to see if anyone could help me source a new filter element for the valve cover under the flat cap.