As a moderator I am expected to try and read through posts on here.
Well this thread is doing my head in, big style.
I am not going to attempt to interpret all that has been written,
but this one doe stand out like the proverbial sore thumb.
As a general rule bigger brakes make it necessary to move the pedal further to give the same braking force on the road because the (generally) bigger cylinders take more fluid to move the same distance. That's certainly one reason for using, e.g., smaller rear wheel cylinders and so reducing their effect. Using bigger back brakes with bigger front brakes is likely to make that lengthening effect even worse.
Brake master and slave cylinder sizes are matched.
Sierras have 22.2mm bore master cylinders, so changing the BMC on a Dolomite to this size eliminates any excessive brake pedal travel for the set up being discussed here,
since the cylinder sizing is as per the Sierra (2 litre petrol).
As to the stuff about "O" levels and maths,
what is the point of research and development and testing?
James Clark Maxwell may have done everything with pure mathematics, but he was truly exceptional
and is sadly rather forgotten in his homeland but not in Russia it seems).
Interesting. But remember that, if you change the cross sectional area of the master cylinder by the same factor as you change that of the the slave cylinders, you keep the pedal travel the same, but go back to the same ratio of forces between pedal and brake pad, i.e. defeat that aspect of the upgrade. What is the master cylinder diameter on the Sprint anyway?
BTW. Am I right in thinking the smaller 1850 servo will require less pedal movement but more input force for the same output force than the bigger Sprint servo, being a smaller gain device?
What I remember about Maxwell is spending hours going through clever ways to avoid solving his equations in Andy Marvin's course on antenna design, because they're too hard to solve at undergraduate level.
With respect to Dr (now Prof I think) Marvin's forename: I'm reliably informed Andy is not short for Android. His level of paranoia is not something I could comment on. But I have to suspect the sanity of someone who claims they can prove that power goes into a resistor sideways. Not sure if that was what caused the pain in all the diodes down his right side though.