Brake Servo vacuum

[mdmax72]

Hi all

Need some help. How is the vacuum connected to your flat six or four if your running carbs? Do you have a small take off on each manifold for each cylinder or just one connection to one manifold going to the vacuum?

[shambly]

Rich,

I've had the servo running both from a single connection on a kadron balance pipe, and on a single tapping on each manifold from IDF manifolds (so 2 of the 4 cylinders).

I'm not sure that we run our engines so on the edge that the extra air injected through the servo feed line 'air leak' will cause lean issues even if on a single cylinder?

You will need to use one way valves on _each_ connection though, so that vacuum doesn't bleed away - this made a huge difference. I seem to remember the plastic part I used came from a T25.

Simon

[mdmax72]

Cheers Simon

Problem is on my old set up l tapped into the back x2 of the x4 inlets. Each time l did a service l always found those I'd tapped into the spark plugs always showed to be running leaner than the other x2. Mixtures was set up correct at the time. My thoughts were the same as yours, that they would make a noticeable difference but the plugs tell me otherwise.

So what l was thinking with the new engine was to tap into each inlet to equal it out across the x4 inlets. Not sure if this is the right approach, hence the reason for the question.

[hot66]

Servo ... Theyre for the impact bumper and later guys

[Lightweight_911]

Why do you need a servo on such a light car ?

[mdmax72]

Hi Andy

When l first built the years ago l had drums on rear and disks up front. Brake pedal always had a lot of travel and under braking. Then l went disks all round and upgraded the master cylinder. Abit better but still a lot of brake pedal travel. So l fitted the servo to help this which it did. Now have a good pedal with less effort to stop.

Personal choice l guess. It's abit like driving with power steering or not...