[Mgs] Emission Connections on SU HIF

[Paul Hunt]

Have a look at http://www.mgb-stuff.org.uk/wn_fuelframe.htm and click on 
'North American Emissions Plumbing'.

Basically the carbs are easy, there should be a 1/4" (or so) port on each 
near the manifold flange which are connected together with a 'Y' connector 
which is then plumbed to the port on the front tappet chest cover.  If you 
have the charcoal canister and all its plumbing then one of the hoses from 
the canister is teed to the carb vent/overflow ports near the intake flange. 
If you don't have the canister then the vent/overflow ports on the carbs 
must be piped down past the exhaust.

The inlet manifold is also easy, any unused ports i.e. vacated by the 
removal of the gulp valve or anti-runon valve must be sealed.

If you still have the canister connected to the port on the back of the 
rocker cover that is fine for breathing, if not you should fit a small 
filter to that port to prevent the sucking in of dust and moisture.  The 
alternative is to seal that port and fit a ventilated oil filler cap, but 
there is always a chance that a non-vented will be fitted at some point in 
the future which will upset the breathing.

The full emissions plumbing with anti-runon is a lot more complicated, 
virtually every hose must be in place and not blocked for the system to work 
correctly.

PaulH.

----- Original Message ----- 

> Anyone have a diagram showing how the emission hoses are to be hooked up
> correctly to prevent vacuum leaks?