Drew,
disc brakes take MORE pressure, that's part of the reason why most new
cars have brake boosters. This also explains the switch to the smaller
M/C. With the smaller piston, your foot moves less fluid per inch, thus
you get more brake fluid pressure per inch travel.
Same with driving in a lower gear - you have more power but you
go a shorter distance.
So if you end up with more pressure in the system, your rear brakes would
overbrake. This would easily be fixed by installing a pressure regulator
in the line to the rear axle.
Ulix
On Wed, 13 Jan 1999, Andrew Griffith wrote:
> Thanks for the reply Larry,
> Well I've done the conversion to disc brakes already, but I'm concerned
> about spinning the car around when I have to hit the brakes, "Hard"! Do you
> know if these earlier cars are prone to locking up the fronts after being
> converted to discs?
> I know that disc brakes require less pressure and fluid to get the same job
> done and when AH went to a standard disc brake in the front they also
> reduced the size of the MC bore from 7/8 to ¾, was this the reason?
> I'm hopping that I'll get responses from racers, who have been there and
> done that.
> My car is still not running, I'm sending the MC to Joe up at Sierra
> Specialty Automotive to get sleeved. As it turns out it looks my brake
> problem was my MC all along, I think. I'll be glad when I get past this
> braking problem cause I'm getting very impatient and want to put in my 120
> HP engine, and I'm not doing it till I can stop as fast as I can take off.
>
> -Drew
>
> -----Original Message-----
> From: Larry and Sandi Miller [SMTP:millerls@email.msn.com]
> Sent: Wednesday, January 13, 1999 12:38 PM
> To: Andrew Griffith; 'Christopher Palmer';
> spridgets@autox.team.net
> Subject: Re: Disc conversion
>
> Drew
>
> The early cars had a single line split at the 4-way union with no
> proportioning valve. You can graft the complete brake system from a
> later
> car if you want or you can just do the drums to disk conversion and
> leave
> everything else alone (What I Did).
>
> If you go to the later dual line system it does require some
> reworking of
> the mounting hole. The later brake box is shorter and wider.
>
> Larry
> -----Original Message-----
> From: Andrew Griffith <Andrew.Griffith@ReadRite.com>
> To: 'Christopher Palmer' <ctp@gbn.org>; spridgets@autox.team.net
> <spridgets@autox.team.net>
> Date: 13 January, 1999 12:28 PM
> Subject: RE: Disc conversion
>
>
> >I've got a question regarding the earlier single brake line cars
> that
> >originally came with front drums... When the front brakes are
> converted to
> >discs should a different proportioning valve be used when running a
> modified
> >engine? Do these early cars even use one? My '62MKII seem to only
> use a
> >"4-way" union.
> >
> >Thanks,
> >-Drew
> >
> > -----Original Message-----
> > From: Christopher Palmer [SMTP:ctp@gbn.org]
> > Sent: Wednesday, January 13, 1999 11:29 AM
> > To: spridgets@autox.team.net
> > Subject: Re: Disc conversion
> >
> > Technical note -
> >
> > Many don't realize that the rear brakes on any car provide only
> >around
> > 30-40% of the braking force applied. In a car as light as a
> >spridget, for
> > street use, drums are plenty on the rear.
> >
> > ctp
> >
> >
> > At 9:30 AM -0800 1/13/99, Ulix Goettsch wrote:
> > >On Wed, 13 Jan 1999, Neesham, Ted wrote:
> > >
> > >> I would like some comments on a conversion of drums to disc. I
> >realise the
> > >> later Sprites had front discs, but any suggestions for all
> round
> >discs?
> > >
> > >Not many people do this, because the Spridget is extremely light
> in
> >the
> > >rear. Discs on the rear won't give you much if any improvement
> in
> >total
> > >braking.
> > >
> > > Ulix __/__,__
> >___/__|\__
> >
>
> >>..............................................(_o____o_)....<_O_____O_/...
> > > '67 Sprite '74
> >X1/9
> >
> >
> >
>
>
>
Ulix __/__,__ ___/__|\__
..............................................(_o____o_)....<_O_____O_/...
'67 Sprite '74 X1/9
|