This sound like a perfect application of a pressure reducing flow valve.
(Brake balance valve) Cost about $60 and could be mounted into the hard line
that goes to the rear axle. Positioned just right with a bit of extra
plumbing, and it could be adjusted from the cockpit. "Dial-a-Brake"?
Corvettes had them stock, and they are in "J.C. Whitless". Tilton might have
them too.
Regards
Calvin Grandy
Vermont
----------
> From: Mike Kerr <mikekerr@innercite.com>
> To: Calvin Grandy <cmgfam@sover.net>; datsun-roadsters@autox.team.net
> Subject: Re: Rear Brake Swap
> Date: Tuesday, November 30, 1999 3:42 PM
>
> OK I've tried all sizes and here is the scoop...
>
> both cars the rear brakes lock up too soon , (if the brake all the way
> around are in good stock condition) the 1600 needs 3/4 inch, and the 2000
> needs 11/16s . the 3/4 inch can be found (btw stock on the 2000), but are
> more $$ than the stock 13/16, the 11/16 are harder to find .
>
>
> Mike Kerr
> Roadster Restoration
> 3730 Todrob LN.
> Placerville CA. 95667
> Ph.# 530-644-6777
> Fax# 530-644-7252
> E-mail: mikekerr@innercite.com
> Web page : http://www.innercite.com/~wolfgang
> Visa & master card
> -----Original Message-----
> From: Calvin Grandy <cmgfam@sover.net>
> To: datsun-roadsters@autox.team.net <datsun-roadsters@autox.team.net>
> Date: Wednesday, November 24, 1999 2:39 PM
> Subject: Re: Rear Brake Swap
>
>
> >The only thing I will agree on is there are good references out there.
> >
> >I would not agree that a smaller wheel cylinder will give greater braking
> force than a larger wheel cylinder compared to system in the front that
> remains unchanged. In fact the force generated at the cylinders will be
> proportional to the cylinder area. Larger area means greater force P=F X A.
> >
> >BUT!
> >
> >In the real world the braking force generated is a function of: coefficient
> of friction X swept area X radius.
> >If the rear brake friction material generates sufficient friction to self
> energize the leading shoe, the brakes will lock at very small pedal/ wheel
> cylinder pressures. The real world case of rusted drums serves as example.
> >
> >The designer had something in mind when the components were originally
> sized. Modern friction materials could alter these factors. Dual brake
> master cylinders, (not tandem!) can serve to refine brake balance as can
> proportioning valves. Drum brakes have a much different performance curve
> for than do disc brakes, so no one setup can work for all speeds and
> conditions.
> >
> >In the case of a modern day performance motorcycle, maximum braking effort
> will result in 100% weight transfer (a stoppie). When the rear wheel is in
> the air, the best and worst brakes perform the same!
> >
> >Regards
> >
> >Calvin Grandy
> >Vermont
> >
> >----------
> >> From: Thomas Walter <walter@omni.sps.mot.com>
> >> To: datsun-roadsters@autox.team.net
> >> Subject: Re: Rear Brake Swap
> >> Date: Wednesday, November 24, 1999 2:03 PM
> >>
> >> This is getting pretty interesting.
> >>
> >> Both Bill and Calvin are correct. Looks like they are saying opposite
> >> things, but not really.
> >>
> >> If you want the REAR BRAKES to lock up first, use a SMALLER rear wheel
> cylinder.
> >>
> >> If you want the FRONT BRAKES to lock up first, use a LARGER rear wheel
> cylinder.
> >>
> >> For you engineering students out there, still in school, have a little
> >> fun with your MATLAB program. MATLAB provides a can routine to you can
> >> see the static and dynamic results in the brake pressure.
> >>
> >> The early (single) and later (tandem) brake master cylinders both have
> >> a single pressure point on the pedal. For racing, it is best to use
> >> an adjustable ballance bar and two seperate master cylinders (I think
> >> Bill Kenyan has such a set up on his vehicle... been a while since I
> >> have seen it -- or was that on Ralph's?).
> >>
> >> QUICK CHECK: Step on the brake pedal... feel how far it goes to the
> >> floor; Now pull up on the handbrake, and try again! If you feel a big
> >> difference... you need to adjust the rear brakes. Obviously the pressure
> >> was the same in both cases, yet the brakes would behave different under
> >> braking... hint, displacement does play a big part of this.
> >>
> >> Carrol Smith has a pretty good write up in one of his "... to Win" books.
> >>
> >> Cheers,
> >>
> >> Tom Walter
> >> Austin, TX
> >>
> >>
> >> P.S. For you engineering students: Front pistons are 2.125" diameter.
> >> Master cylinder is 3/4". Rear wheel cylinders can be 11/16" , 3/4",
> >> or 13/16". You'll always find the LARGER rear wheel cylinder will have
> >> more STATIC pressure... but add displacement volume, and observe the
> >> dynamic results.
> >>
> >>
> >> >From: "Calvin Grandy" <cmgfam@sover.net>
> >> >
> >> >When considering fluid power (hydraulic brakes) The work is done by
> pressure not by distance. This is not the true definition of work i.e.
> Force X Distance, but is what we are considering. If the small cylinders
> move out more rapidly under pedal application, so what! The resistance to
> movement, when the shoes hit the drums, will result in a build up of
> pressure that will extend any sluggish members (front caliper pistons
> perhaps). When all the free play is taken up, then the real pressure will
> build, and the work of stopping can be done.
> >> >
> >> >If the wheel cylinders are smaller, the resulting braking force may be
> smaller (do not neglect the self energizing effect of the leading shoe) and
> there will be less pedal travel before the brakes start to "bite", A higher
> pedal action.
> >> >Mechanical adjustment of the pedal linkage can reposition the pressure
> point of the pedal if desired.
> >> >
> >> >Please do not construe this as an endorsement for the exchange of wheel
> cylinders! I do not know what the results will be. I just want to make
> clear the nature of the system.
> >> >Regards
> >> >
> >> >Calvin Grandy
> >> >Vermont
> >> >
> >> >----------
> >> >> From: SRL311KA@aol.com
> >> >> To: toby@wolfenet.com; datsun-roadsters@autox.team.net
> >> >> Subject: Re: Rear Brake Swap
> >> >> Date: Tuesday, November 23, 1999 10:24 PM
> >> >>
> >> >> Hey list,
> >> >> Pistons in smaller rear wheel cylinders will move further than
> larger
> >> >> cylinders with the same amount of pedal depression. Think about it!
> >> >>
> >> >> Bill Kenyon
> >> >> SRL311 KA
> >> >
> >
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