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8556

[VintageLambo] Espada Brake Vacuum

Laust Pedersen

So I finally got to measure the vacuum that the brake boosters see and here are some numbers: 7.5 in Hg at about 1000 rpm idle cold and warming up 11 in Hg at about 2500 when warm 2.5 in Hg when thoroughly warm idling at about 800 rpm 15 in Hg on overrun from 3000 rpm 19 in Hg on overrun from 5000 rpm Blocking the longitudinal balancing pipes (from pulling slight vacuum in the crank case) gained only ½ in Hg. In my installation the flow path to the crankcase is restricted to about 1 mm diameter on both sides. I simulated the standard set-up by blocking the flow to the Idle Speed Motor (ISM, unique to me), which is connected to the two longitudinal vacuum tubes. It is surprising to see that the vacuum increases as a function of rpm under no load conditions. Fully warmed up and at low idle the vacuum is inadequate to assist the brakes, so my previous assertion that driving in slow traffic will deplete the brake boosting is certainly explainable in my case. I would be very interested to see numbers on other 4LV12 engines. Otherwise I will have to conclude that our engines really need an electric vacuum pump which typically generates around 20 in Hg. Laust ------------------------ Yahoo! Groups Sponsor ---------------------~--> Yahoo! Autos. Everything you need to know about buying or selling a car. FREE Quotes, 360° Tours, Research, Blue Book, Compare Vehicles, Buy Used http://us.click.yahoo.com/kEZsdA/bwnGAA/YiGOAA/9jLplB/TM ---------------------------------------------------------------------~->