do the vented (drilled) rotors help stopping power noticably or should I upgrade to 11" rotors, I was told the fronts need a little help on a new project car I picked up.spedways got both drilled and stock w Chev Or Ford BC's for 35$ or the 11" upgrade kit for $250ish.(which move the wheels out 1" per side)
Really depends on the weight of the car, model a/t 32-34 small drilled will be fine, big fat fendered car go with the 11 inchers!
its that 46 chevy PU a few posts down , 'glass feders on 4 corners, VERY light truck, we can lift the front end (w/o motor) by hand- 1 guy on ea side and we are'nt gorilla's, guesstamate around 3600# w a motor
the other question is what calipers are you going to use? check out ECI engineered componants incorporated. later jeff
Thanks but ECI is WAY out of my price range,there are a plethera of company's making this MII stuff,Not saying that ECI or Heidts does, but most is no better than Speedway and in fact use the same suppliers,so its going to be Speedway either way I go,The Speedway 11" it uses chevy calipers, right now it has stock MII (4 bolt bc)with 5"bc adapters on it -THEY GOTTA GO.wheel adapters on the front of anything, is just plain dangerous.
Mustang II brakes were designed and engineered to stop Pintos! (The Mustang II just borrowed the Pinto platform in 1974-78) Even at 3600 pounds, your about a thousand pounds over the weight of a Pinto, with a heavy V8 over the front wheels being stopped by those Pinto brakes. Mustang II brakes are cheap, light and easy to adapt to other vehicles, but you're still employing technology meant to just barely stop an early 70s econo compact. The larger rotrs, or drilled ones may help dissipate the heat better, but it's still just band-aiding the problem, escpecially if stock Pinto calipers are used! The ECI way may not be as pricey as you think. I called them and discussed a brake upgrade for my 49 Chevy car, and they have a bolt-on kit for that, and many other applications. The entire kit IS a bit expensive in one lump sum, but the components used are over-the-counter OEM parts available from any local parts joint. ECI will sell you just the mounting bracket(s) and hardware, along with a detailed list of required OEM parts to complete the swap for far less than the cost of their complete kit. This offers you the chance to buy the rotors, bearings, calipers, etc a little at a time locally if you are on a modest budget. (The ECI kit for my car uses Chevelle/Monte Carlo brakes. My car weighs 3000 pounds, but will probably only really weigh around 2700 by the time I'm done with it. Chevelles and early Monte Carlos weighed around 3400-3700 pounds with V8 engines and full frames. Mustang II stuff might be just barely adequate for my ride, but I'd rather have stopping power meant for a larger automobile on tap if I ever need it!) Some ECI kits may use 1970-81 Camaro/Nova stuff...those cars were still 3000-3300 pounds, making those brakes a good choice for most typical rods as well. No slam against Pintos and Mustang IIs, I've owned and built several of each and I love 'em...but I wouldn't trust their brakes under a fat fendered GM rod or custom with V8 power!
I have some larger MII rotors and calipers? on the shelf. A customer pulled em off to install something high zoot. I can ask him what he wants, I am tired of trippping over them (its a long story)
I went with the stock (rebuilt) M-II brakes on a 1938 Chevy, and the stopping was GREAT. I used the 11" brake on a 1946 Ford, and I never could get that car to stop like I wanted. My take?? Use the stock M-II brakes, and see what they are like. I talked to Gary Heidt about this, and he agreed that the stock M-II brakes are fine for most rods, and that the 11" brakes are overrated. So, since you are down on bucks (aren't we all ), and the best option (IMHO) is to go with the stock M-II, which is also the cheap way...hey, what a choice, eh?? Something else to consider: Are you using a floor, or a suspended pedal?? IMHO, the suspended pedal (from a donor car) is better. Match the master/booster to the front brakes.
good info , I'll keep it in mind as I'm not a MII guy, mostly I beams and stock sprung front end experiance, , I have'nt driven this thing yet and when i rode in it last summer, it seemed fine to me, but riding and driving are 2 different things,I'd like to drive it then decide if i want to go bigger-- TMAN check em out for me ,maybe that would be the way to go to.What BC? can go either 4 3/4 or 4 1/2 bc. Thanks
the truck uses a Monte GM metric power master cyl (plastic snap on cover)and prop valve, another thing I am thinking is it may be mismatched conponenets, the pedals also Monte are suspended down from the dash which has been reinforced to take the strain.
I'm gonna disagree with FatHack here. While the Pinto DID weigh a lot less, after 1973 both the Pinto and M-II gained a LOT of weight (well over 3000# at the end, with V8 and air, etc). Too, the engine on the M-II WAS a V8 (optional, true), and it was positioned nearly in front of the wheel centreline. This is why the four cylinder springs are recommended for rods, the engines are positioned nearly in back of the wheel centreline. Now, the brakes. As I said, I had no problem with the stock M-II brakes on a 1938 Chevy. A little lighter than your car, true (2800#), but I drove that car DAILY (it was all I owned), and HARD. Never had a moment I wished for more brake. OF COURSE you could spend more money, But why not use the stuff you have, and if it proves less than you need, THEN upgrade. The M-II brakes WILL stop your car, no safety issues, and you won't have spent a lot of money that might not be necessary. Cosmo
One last thing that most people do not know. The sole defining area of brake efficiency is weight. The weight of the rotors, that is. As a brake is nothing more than a heat disappator, and the rotor's main function is to store and disappate that heat, how much heat it can store is how well it will brake before fading. Weight is the key to storage of heat, more weight, more heat. Drilling a rotor will lessen it's weight, lessening it's ability to store heat. Drilling will also lessen the area that the pads bear upon, lessening the braking force available. The reasons that people drill rotors are: To look cool. To scrub stainless particles from the pads (not much of an issue with cast iron rotors, really). To disappate heat with more surface area. This last is a close call with braking area. And I suspect that the "looking cool" overrides any other judgement in this area. But, as a rotor is a heat sink at it's core, and as any drilling will open up the rotor for cracking between holes due to localised overheating, I would shy away from drilling any cast iron rotor. That all said, it's still your call. Cosmo
My trucks weight is just a guesstemate , I'd think it would come in some what less than a 38 chevy 2 dr sedan, I am going to drive it as it is I think, but will change out the rotors to get a 5 bolt-bolt circle, those adapters scare me more than the brakes do. I have had some bad experiances with them.
I am using grenada rotors and calipers on my 41 Chevy PU. They use the same bearings and give you a 5 on 4 1/2 pattern. The brackets are easy to build, just some 3/8" plate flame cut and a small piece of heavy wall pipe welded on. Relativly cheap and easy.
Another factor to consider when using Mustang II/Pinto brakes is the size and weight of the ROLLING STOCK! Pintos used 13" wheels with skinny little tires, and Mustang IIs only got 14" wheels at best. Us 4x4 guys know what happens to brake efficiency when you slap a set of 44" mudders on your rig that could herniate Brock Lesnar...the added weight, rotating mass and leverage generated by the increased tire diameter tax the rig's brake system to the max! Throw a set of Pinto brakes on an old fat fender car with 15" steelies and some big ol' whitewalls, and your adding more rotating mass than those brakes were ever designed to handle, in addition to increased vehicle weight and horsepower! (Even if you loaded all your buddys and their rock collections into your Pinto wagon to get the weight up to 3300 pounds, the vehicle would still have miniscule horsepower and 13" wheels. Still, stopping would be compromised, if only a little. Add a V8 engine along with 15" steel wheels and bigger tires to the equation and you can see how much harder those brakes will be working!) The automakers don't like to make anything beefier than it absoloutely HAS to be, as that cuts into the profit margins. The braking system on 70s compacts were just about effective enough to work within their designed limitations, and not much more! Nobody ever thought that Pinto brakes would be called upon to whoa down 4000 pound cars with big block engines and heavy rolling stock, and they sure weren't engineered with such extremes in mind! To their credit, even over-taxed Pinto brakes are likely to be as effective as the stock old drum brakes were, but if your going to upgrade to disc brakes in the name of BETTER stopping power, it's wise to select components from OEM applications that share similar weight, horsepower and wheel/tire characteristics with the type of vehicle you are building. If you have a healthy V8 in an all steel shoebox, you're better off to use brakes from a Chevelle that could weigh up to 4000 pounds and come equipped with an LS6 454, than you are to rob brakes from a 3000 pound compact that never had more than 150 hrsepower, and often much less! Of course, with quality aftermarket components and improved design and materials, the Pinto brakes CAN work just fine for many rods and customs, but the cost difference between common GM intermediate stuff and Pinto parts at the local parts joint is minimal, and the improved braking effort more than makes up for any difference! (My last Mustang II was a built-up, all steel Ghia coupe with a 351W that tipped the local scales at just shy of 2900 pounds, to give you an idea of what those cars realistically weighed.)
now that I had'nt figured in , he had 16" 70 series BIG tires on it and I am going to 14" F-75-14 skinny's w McCreary G 60 all nos tires found locally.
DG.... here's my .02..... had a 50 chev coupe...small block chev..mustang front..power booster,residual valves and CORRECT proportioning valve .....on a sudden stop it just WOULD NOT stop FAST enough !!! Changed to the 11" rotors and it was night and DAY !!! if I were installing a new system I'd do 11"ers on ANYTHING !! Jersey Skip
Cosmo, the way I understand it, getting more surface area to dissipate heat is only one of the reasons to drill thr rotors. They also get drilled ( or grooved ) because in extreme situations, enough heat will be generated between the pad and the disc that there will be a cushon of gas trapped between the two, reducing the efficiency. Drilling or grooving will make that gas escape easyer.
There is another problem with MII discs, and FH already mentioned it. They were designed for 13" wheels. This is my line of thinking, and please correct me if I am wrong... A car going down the road has a certain amount of energy. This energy gets fed into the wheel and with the distance from the road to the spindle, it is a torque. Going back with the distance from the spindle to the caliper it is a force again. In other words ( with every thing else being equal ), bigger diameter wheel= less braking, caliper closer to the rim ( moving it away from the spindle )= more braking.
This has turned into an interesting debate ,I think I'll print it out for future reference, some good points
Metalshapes...that's about right. I used the big 4x4 example because it's an extreme one...bolting on HEAVY (believe me!) 44" tal tires where 30" ones came stock. It's the same effect as putting a steel tube over a ratchet to gain more leverage. Taller tires on larger wheels weigh more, as well as having added leverage to act against the brakes. Put that weight into motion, and the greater rotating mass is much greater than it was stock. Add more horsepower and increase vehicle weight... ...and at BEST you wear out pads prematurely and warp your rotors from the excessive heat. ...and at WORST...you plant your clodhopper on the pedal and she just won't stop in time! Cutting corners on your paint and bodywork, or sound system, or horsepower upgrades until you can afford to do it better is one thing... ...but using econo compact brakes to save a few pennies (if any, really) isn't a good idea! Pinto brakes work good on PINTOS....and on other really light cars...but I dunno about using them as an UPGRADE for bigger, heavier cars with larger rolling stock and more power!
totally agree with the hack.. check eci out MOST of their stuff is oem parts. and brackets to get the best brake set ups.. I do know this.. no one has ever said to me that they had too much brake... too much power.. yes..
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