Race Engine Forum UK

Guy

This is an IDF Manifold from a GP1 Mk2 Escort RS 2000. The brake servo ports are very interesting, this is a setup I've never seen before....but when you think about it, its quite an obvious solution to a problem I've had on several Duel Carburettor set ups over the years. Its four separate ports from each cylinder all commoned up onto a separate manifold to equal the load from the servo. My rolling road operative (Dave Bogg) nearly always has to over adjust the balance of the one cylinder closest to the servo port to get it anywhere near the same as the other 3, which causes inherent fueling issues further up the power band.

I was wondering if you can see any issues with this design? As to me it seems to make a lot of sense and on the face of it and therefore worth copying.

If you use an in-line non-return valve (as fitted to Fiat 124 Sport) on the runner with servo it is a non-issue.

If you don't do that it is pretty-well impossible to get good idle and balance.

G

In my opinion the 4-holes are for the vaccum gauges if have you calibrate the setting of the throttle valves from the carbs. Normally there must be some sealed plugs in it.

Some carbs like the weber dcoe have this gauge port in the plate of the carb, but some other carbs don't have it, so therefore you have Them in the manifold.

The brake vaccum port must go to the big plug on the second of right.

Nils

That wouldn't make a lot of sense of the usefulness of the second part in the opening posting.

I would never bother with vacuum tappings for balancing carbs. And 4 manometers? No way.

C:\Documents and Settings\Guy Croft\My Documents\My Pictures\syncrometer.jpg

GC

Guy as long as you have trumpets its the easiest way to use the weber synchrometer, but some standards carbs like the 44 PAI, I have three of them mounted at my boat engine, they don´t have trumpets. See pictures below no chance to wor with you tester.
Or the bikes, where you have no space are using this special vaccum gauges. If your are interested I can send you an link by PM, cause it´s not my own picture.

Here my carbs on 3L 6-inline Volvo