1/4" or 3/16"
I can think of a few pros and cons to each, but would like to hear more input.
My gut leans me toward 3/16… but the 1/4" stainless lines and fittings are all free.
What are the pros/cons?
Brake fluid does not really flow right?
.25 line and you are pushing more fluid. From what I understand you need a bigger cylinder then. 3/16 is fine for almost all apps.
edit: now that I think about that it really might not make logical sense.
Go with the free I doubt you will notice the difference
What’s the application? 1/4" can be a PITA if every fitting on the vehicles brake components (master cyl, wheel cyls, calipers, etc) is sized for 3/16"
You will be displacing the same amount of fluid, there is just more of it.
Pros: more volume = lower temps
Cons: more volume = more fluid to absorb water
I’m sure there are more…
Master is 3/16.
Calipers are 1/8npt
Either way i am going to need adapters.
More adapters are more opportunities for leaks. If you’re worried about water absorption go with silicone brake fluid. Just be sure you flush ALL of the old fluid out or you will hate life.
Another con is that there is more area for the fluid to act on = softer feel.
However, the 3/16 would probably be mild steel, 1/4 would be stainless.
Lotus? Or bimmer?
The size of the line shouldn’t have much of an effect on pedal feel. As long as the ratio of the surface area of the master cylinder piston stays constant with the surface area of all the caliper pistons/wheel cylinder pistons the mechanical advantage stays the same.
This is a totally scratch built system.
It’s in a BMW using a honda master cylinder, with wilwood superlite calipers at all 4 corners.
More adapters are more room for leaks, but it’s only an issue of adding two adapters.
If you ran the 1/4 inch line I would consider upgrading your master cyl.
In theory by going from a 3/16 line to 1/4 you essentially add ~40% more volume.
Area of 3/16: .028 in^2
Area of 1/4: .049 In^2
The cylinder may have an adverse affect and you could loose braking power, yes?
Which is cheaper better master cylinder or SS 3/16 lines?
3/16ths is perfect .
3/16
I would probably go with the 1/4", building shit beefier (and getting materials free) appeals to me over the complications I might run into by using bigger parts.
Id go with free 1/4 line, in a proj like your bmw i bet $ its just eating at your wallet so free works as much as you can get it . At least on my 68 camaro every time I get ahead im set back another 40 dollars here and 150 there for little things.
just because it is 1/4 lines, doesn’t make it any beefier or more durable/longlasting/
The bigger the line, the more material to flex/deflect/stretch. I’d expect the 3/16" to give a firmer pedal feel.
Wait, are we talking all metal tubing? If so then I’d bet you’d never feel a difference.
Wait, you already brought this up in post #9.
OK then. Free + Stainless > oversized + two fittings. IMO.
The temperature difference of the fluid is almost certainly negligible between the two!