The V8 Owners Forum -

Just changing my SU's for a flapper system today and its all fitted minus the loom but what im needing to know is what are the 2 breathers on the underside of the plenum at the throttle butterfly? Can anyone help me out or help me or hook me up with a link to a diagram of the setup.

From memory it sounds like you are talking about the two connections to the cooling system

Yes indeed.
One should go to a stub pipe on the inlet manifold near the temperature sensors at the front.
The other one goes to another stub pipe, this time I think it's on one of the pipes that runs from the water pump rearwards in the valley.

Chris.

In my view they are better left not connected unless you live somewhere very cold.
The hot water warms the inlet charge reduces power, just my opinion of course

K4000JB thats what ive done bud, the car is all done up and running and it is a great improvement on the SU's. I had it out for a good 30min on a test drive with no issues but since driving it home it has developed a miss that seems to be getting worse but ive not had a chance to look at it, going to change the plugs etc. I can live with some teething problems im just glad it fired up and ran on first attempt.

Next question, it ticks over pretty high, is there a way of adjusting this or is it a case of a sticky stepper?

If it's a flapper, fast idle is via an extra air valve which has no clever control - it simply works on engine temperature (plus an electric shunt coil). The base idle speed is set by a screw on top of the plenum. This controls a throttle bypass bleed.

Maybe worth checking for an air leak in my opinion, ramon albon(sorry spelling) On here has a great site for the flapper system on the sd1 iirc

Cheers guy much appreciated I will let you's know how I get on! Is there a link to Ramons page or a name for his site?

Try this
http://www.vintagemodelairplane.com/