what do these knobs do?

[lurtch]

Hello All,

Perhaps some of you saw this photo in the new Hagerty Magazine.

Who cares to weigh in on what the manifold block and its push-pull valves might do?

Larry in CA

[Tyler S]

I remember reading about a rudimentary antilock brake system on the slr race cars. Oil was squirted onto an offending wheels brake to keep it from locking up. Would assume one knob for each wheel.

[WRe]

Hi,
Tyler is right. In those days it often happened that drum brakes blocked during the race. Therfore one could spray oil in this drum to unblock it, one spray knob for each drum brake. Today this sounds very unusual.
...WRe