Dan,are you kidding me!!!Every pound counts on a street car,and to save (by your calculations)3 lbs on just a master cylinder is very substantial in my book.

If you are telling me that weight doesn't count then I would agree,but as far as I know every pound off = quicker car.Loosing that boat anchor starter and adding a mini starter is just another example of trimming lbs.The 4 bolt type will work fine,but the 2 bolt master is the better set-up.

PS:Stock push rod works just fine,65 Dart.

JZ

Yep, and use light shoes, instead of boots when driving.

If that is the only light part you end up with, I wouldn´t bother...
If you are going racing with a gutted car, sure!

Stock pushrod + 1/4" thick adaptor plate = lower brake pedal height by a little under 2". If you have the travel to spare, that's fine, but if you don't....!

I really don't worry about how much my starter or my brake cylinder weighs.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dan,just wondering how you have a little under 2" drop in the pedal when all you are adding is a 1/4" adapter plate?


JZ

Now that I think of it the adapter plate is machined out so the master cylinder fits inside of it leaving milimeters of a difference from a stock master cyl.

Because of the pedal ratio, which is:

(distance between the pedal swing pivot and the pedal pad) ÷ (distance between the pedal swing pivot and the pushrod).

The complete pedal travel at the pad, from top to bottom, is something like 7 inches. But does the pushrod move through the same 7" travel? No, it only moves less than one inch, because the pushrod is anchored much closer to the pedal pivot. (If it moved the whole 7", the piston would eject through the front of the master cylinder...) The reason why there's such a large ratio is that you need to gain mechanical advantage over the master cylinder. If the pedal ratio were 1:1, you'd never be able to develop enough pressure to stop the car. Try to apply the brakes by putting your foot on the pedal arm above the pad sometime, and see how much more difficult it is!

I'm estimating the pedal ratio at around 7:1. It might be closer to 6:1 or closer to 8:1, but 7:1 is in the right ballpark. That means for every 1/4" you move the pushrod (as, for instance, by shimming the master cylinder 1/4" away from the firewall), the pedal pad moves by seven times that amount, or 7/4" = 1-3/4".

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Not the MP adaptor -- it's just a flat 1/4" plate with two studs and four holes. Perhaps somebody else's adaptor is machined as you describe.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dam Dan there ya go getting all rocket scientist on me.......

Just wondering why it didn't work on your 62,are you saying the adjustable push rod wasn't long enough?


Anybody else(63 & on)) that has thought of doing this conversion don't let this deter you it works perfect.


JZ

Wasn't short enough. Brake pedal was too high.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

All that fuel down the drain but for forgetting to hang a crap before I head out on a road trip.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I had the same problem on my 70 when I did the swap. Ended up buying a Master Power adjustable rod and cutting it down so I could use it...

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70 Dart, 360, 727

Yeah I recommend a personal trainer--you can easily loose 100 pounds off your car that way. OR let my son drive...he's only about 25 lbs at the moment. He's been busily building his first thin-walled metal open top racer. The wheels are a little large, but it handles well on the streets:



Not to poke fun, but I'm quite familiar with the weight savings issue. In a former life, I was a semi-pro bicycle racer. Every frickin' piece of the bike had to be made from unobtainium and people would spend thousands to shave a little bit. It usually works out that you can shave a fair amount on your first pass pretty cheap, and then consecutive efforts costs exponentially more. Rotating mass far from the centerline of its spin is your first priority clearly, but even there, on a car, there's far less of it than a bike (lighter wheels for sure, perhaps crank and other engine parts, but even there...). I'm sure it can make a difference, but on a bike, when you wheel is 27" or so in diameter, and you have most of the weight 13.5" from the rotational center, and you have to accelerate that mass, you'll realize a lot of gain from reducing that weight. Pedals are also the same. The block of a car is so damn heavy that shaving 20 lbs for most folks isn't that critical. Even in drag racing (which I have never done) I'd think working on getting a good reaction on the start line would be time better spent than shaving every last bit of weight from your car. Sure, all things being equal less is more (assuming it doesn't break), but then again...few of us compete at that level.

Wow! Sorry, total tangent. Yes you can always save weight, and a few pounds all around will add up, but you have to weigh its cost too. *steps off the stage*

Bicycles were better in that respect--you can train a little more and still beat the crap outta those guys with a $4000 bike that still just aren't as fit. At the elite level, you get sponsorship so it made all the difference for me then.

MJ

NewLancerMan, that's related to how I justify keeping my old bike: If it's for exercise, why not have a heavy bike? Steel frame, 26" X 2.125" knobbies, spring-mounted "wideload" seat, and all. I consider it the bicycle equivalent of a rat rod.
I use more calories going around the block on my Heffy ... err ... Huffy "mountain bike" than I would taking one of those expanded nomassium featherweights across the Texas Panhandle. Ok, so I see less scenery. I also get done quicker!
Hmmm ... that reminds me ... I've had that bike for 20 years this summer. Whodathunk?

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Old Raleighs here, with Sturmey-Archer gearhubs. One underdrive gear, one direct, one overdrive. Brooks leather saddle. 26" x 1-3/8" tires. Not a lightweight, and has to be hauled up hills, but there's something to be said for inertia!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

That's funny, I've been saying that to "fitness" experts for 20 years. Why have a light bike if you're riding to get fit? Great minds...

I also take the stairs on anything less than 6 floors, so call me nutz! You can almost always beat an elevator to 4-5 floors if you don't have to wait for it. I call it "free exercise" since it doesn't cost any time or money.

Lou

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Home of Slant6-powered fun machines since 1988