IML: Dual MC Conversion Logic Puzzle

[Kenyon Wills <imperialist1960@xxxxxxxxx>]

I did a conversion on my currently unfinished/untested
1960.  

I have been talking to Mark Lamp about his brake
lockup problem on the phone and his problems now have
me questioning my setup.

In general, I really abhor putting non-stock parts
onto my cars.  The 67-69 supra disc conversion is the
only one that seems to make sense.  I do this because
I generally think that I'm not in the same position to
make intelligent design decisions as Chrysler
Engineering was when the car was designed, and I
really want the car to work durably and correctly for
the long term.

On the other hand, the single master cylinder setup on
the older cars is admittedly not as safe in the event
of a failure, and I plan to drive the car quite a bit,
so decided to deviate from stock on this one item.

So I violated my own rule of going stock and am now
second-guessing myself, and here's why:
=================================================
I put a 1967-69 full-size Chrysler (Newport, etc.)
Bendix Master Cylinder on and fabricated new brake
lines and installed 100% new everything brake-wise.

http://imperialclub.com/Yr/1960/Kenyon/Page09.htm
Photo E = front brake
Photo F = rear brake

I roll the car out of the garage and down the driveway
and they work great for that, seem to be operating on
all 4, but they are untested in a driving situation
(engine not done/installed yet).



The 1967-69 cars had Bendix brakes.  These have one
two-piston wheel cylinder per wheel.

=====================================================
http://imperialclub.com/Yr/1964/FSM/html/05-002.htm
http://imperialclub.com/Yr/1964/FSM/html/05-003.htm
=====================================================


The 1960 that the 67-69 MC is on has the older Center
Plane brakes that have TWO! single piston wheel
cylinders on the front and one dual on the rear.   

======================================================
http://imperialclub.com/Repair/Lit/Master/138/page07.htm
======================================================

The question that I have is:  If there are two on the
front and one on the rear, is there a difference from
having one on each?  (I don't think so?)

Since the single piston ones on the front are
functionally similar to having a dual, as there are
still 2 pistons per corner that are similar (I think)
in size, shouldn't things be the same?

This all comes down to measuring the diameter of the
1960 wheel cylinders and comparing them to the
diameter of the 1967/69 cylinders, I suppose.  

The 1960 single MC Applies pressure to all 6 wheel
cylinders equally.  The 1967/69 applies pressure in
either equal or unequal rates depending on whether
those wheel cylinders are the same size.  Since they
are Bendix, and the Bendix on my 1964 are the same, I
am leaping to the assumptive conclusion that the 67-69
bendix are also the same inner diameter, front and
rear.

If all four 67-69 wheel cylinders are the same inside
diameter, and all 1960 wheel cylinders are the same
inside diameter, and all have a total of 2 pistons per
wheel, they should operate the same, riiight?

Lastly, the 1960 Wheel cylinders appear to have a
larger diameter, so the same amount of pressure in the
line might move them fractionally less?  Pedal travel
seems very acceptable, and I'm not bothered about it
so far.

Did I mention that I absolutely hate math and consider
myself a marginal engineer?  Now that I'm thinking
about this, I'm fretting about it, despite having a
car that's set up, done, and seems to work
superficially.

Will the 3 club members that are still awake after
reading this offer a technical opinion?  I'll probably
leave the stuff on there till I get to drive the car,
but would like to be mentally settled, so that's why
I'm asking.  

Kenyon Wills
 
 






















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