Inmate Central

Posted by Timbo in Oz (A) on July 11, 2005 at 21:31:15

In Reply to: Re: This looks like a job for Timbo posted by subcoolman on July 11, 2005 at 17:22:39:

they initially used a single piece of friction material formed into a circle and held in a cover, so enclosed and so they did get quite hot, but you don't do landings to a braked stop over and over.

IIRC it was Dunlop (I vaguely recall some US coys involved) who developed these, and the later ones for cars, testing them with Jaguar on the XK120C long distance sports racing cars, and the later D's, helping both Jaguar types win the Le Mans 'Le vingt quatre heure'. Enzo wouldn't go over to discs, for far too long IMO. JBTW I've ridden in both Jaguar types at race meetings and done a few gentlish laps. The 120 is a much bigger car than a D which feels tiny. There really is bugger all room for 'the passenger', the 2nd seats were tokens. Seat belts!!? WO' ah' they!?

Kava's description is quite apt re friction area, howsomever the reason for a greater friction area is to convert kinetic energy / momentum into heat in as quick away as possible, and we have a lot in car going quick.

Drums cannot match the discs swept friction area, and discs don't fade in quite the same way as drums do, as a drum heats up and expands its radius/circumference increases, and the shoes have to travel further and so does yr foot. A disc OTOH reduces the distance for the pads to travel as it heats up. It is entirely possible to run out of brake pedal/lever travel on drums, yes the fluids pretty rooted at that point.

I've done it!

My brother once drove an MG TC racer, cycle guards, big Lucas lights, lots of cooling fins on the bonnet.

Painted BRG of course, with an Aussie flag. Finned aluminium\bronze surrounds sweated on to the drums, sintered iron linings and the thus 'essential' vacuuum booster, and high bp fluid.

Bored to 1500, lightened flywheel, lightened valve train, balanced crank, a special blower cam, light rods and pistons. Judson blower between the dumb-irons with the biggest Amal carbie I've ever seen, and two head-gaskets, one quite thick, and one thin so he could run Avgas / a bit of alcohol for races #, gave about 12:1 cr NOT considering the blower. There was a steel-mesh cover over the blower. Big deep radiator, oil cooler and bigger pump, twin 2 inch exhaust running into one 4 incher just below the passenger's door. BIG fuel cap.

It even had a 'take-off' Brooklands type silencer so the fuzz couldn't hassle you for not having a muffler. Triangular like a flattened cone, but it was still deafening! Crackle, crackle, Banga banga, crackle, blaaaatttt!

# If the starter motor flubbed out on race days we had to push-start it, hard work, REAL race-car stuff, see! ;-)!

I learnt to drift in that car, to double de-clutch, down-shifting etc.
We regularly lost the brakes going up and down the hill-climb road in King Edward Park right beside the sea in Newcastle city.

It could cope with big Ford Customlines* in a straight line drag.

* Big late 50's early 60's things with Y-block OHV V8s, and cocoa tin sized brakes IYTMM.

Warmest

Timbo in Oz
The Skyptical Mensurer and Audio Scrounger

'Still not saluting.'

Read about and view system at:

http://www.theanalogdept.com/tim_bailey.htm