OK Adrian, that answers the question about which master cylinder is better, I would say the early one like you are using is potentially safer. Must have been more expensive to produce and incorperate into the cars and that is why Honda made the change. Doesn't make sense to me.

By Adrian (Evocivic) (203.42.97.141) on Friday, December 17, 2004 - 10:58 pm:

Actually I'm using a 1st gen master cylinder (stainless sleeved with new seals) on a 2nd gen booster(you need to file the mounting holes out a couple of mm to make it fit on). I like the early twin reservoir cylinder as it is a genuine dual circuit. With a single reservoir if you get a leak in one circuit the fluid will still all eventually drain out whereas with the dual system one can empty and the other will remain full. I'm using the EN booster as it's newer (as John S. said) and and all the 1st gen boosters I've used have been a bit iffy.

By Justin (24.83.36.37) on Friday, December 17, 2004 - 08:47 pm:

I have 12.3" front rotor's 11.3" rear rotor's and the nsx calipers.. the stock master would not suffice

I've built quite a few 4 wheel disc set-ups and all have had good braking with the stock master/booster.
their are 2 '78 hatches and 1 '79 wagon and 1 '76 hatch
The only one having soft brakes is the '76 hatch. it runs dual masters and seems to have the same pedal fade as Kyle's wagon.. I'm going to upgrade the master/booster and see how it reacts

By John S. (68.92.140.5) on Friday, December 17, 2004 - 08:21 pm:

Kyle,
Will you be running the NSX brakes too?

By Kyle Thomson (24.83.12.187) on Friday, December 17, 2004 - 07:41 pm:

John S. yes I've talked to justin on this one =), he's actually running NSX front brakes on his wagon. Me and him went around a wrecker one day with a parts book looking for a larger bore master that would bolt up, and found the legend one will work as long as the booster is used as well. It may require some trimming to the upper lip on the firewall, but we're unsure as justins wagon doesn't have those edges (part of the motor swap). He's running his car with it and said it made a huge improvement

By John S. (68.92.140.5) on Friday, December 17, 2004 - 07:24 pm:

You snuck in on me Adrian...

By John S. (68.92.140.5) on Friday, December 17, 2004 - 07:22 pm:

Hey Kyle, you might ask Justin, as that is the setup he has been running for quite some time on his wagon with no problems. Must be that the differences between weight and wheelbase somehow or another cancel each other to the point there is not enough difference for it to be a problem.

By John S. (68.92.140.5) on Friday, December 17, 2004 - 07:14 pm:

Kyle,
"John" is I believe what we might term a "newbie" to the group, and from what I've read of his posts so far is knowledgeable and has been helpful, He and I "John S." are not the same guy. Sometimes it does get confusing...
Anyhoo the 2nd Gen booster is maybe slightly larger but of a "2nd Gen" design which is to say an updated version of the earlier one. How much different I am not sure, but we DO know the are not as OLD. Honda usually only changes things for the better, so one might assume...
I know Adrian uses one in his car and therefore believes it to be better. Also all USA Civics went over to the single resevoir in "76 or '77, can't say which of the two, the single or the dual is better, probably depends on your ultimate useage.

By Kyle Thomson (24.83.12.187) on Friday, December 17, 2004 - 07:14 pm:

I've bled the brakes on numerous occasions hoping it was just that, I've done it at least 3 times and it hasn't helped. I may try taking the master off and bleeding it in case of trapped air. But I really won't know if it helps until I get it back on the road. And I didn't really want to put it on the road until I knew it could stay there

John: yes I fully trust that honda can design brakes, but I don't think it was their intention to have rear disc's, as I am pretty sure the proportioning on the 79 wagon, and the prelude I robbed the parts off of are not the same

By Adrian (Evocivic) (203.42.97.141) on Friday, December 17, 2004 - 07:11 pm:

You snuck in before me Don .

By Adrian (Evocivic) (203.42.97.141) on Friday, December 17, 2004 - 07:10 pm:

The standard master cylinder should be fine. EN master cylinder and booster should bolt straight in with a minor mod to the actuator shaft if you want to use one of them. The pistons in calipers and wheel cylinders really don't move very far at all and don't need a vast volume of fluid to do their job. If you ask me there is absolutely no way they would use up all the fluid in one stroke of even a standard master cylinder. You've either got air in the system or your master cylinder is buggered.

By Don (199.2.139.229) on Friday, December 17, 2004 - 06:49 pm:

You have air in the system most likely.
My stock 1200 bakes with no booster (only race pads will lock the brakes and the pedal is high and hard. Basics Basics Basics

By John S. (68.92.140.5) on Friday, December 17, 2004 - 06:15 pm:

Kyle,
What Don, and now I am trying to help you see is you don't need to over complicate things by changing master cylinders and messing with brake biasing at all. For your street car the stock master cylinder , or maybe a 2nd Gen one is large enough. You can leave the rest of the plumbing alone. Honda knew what they were doing.
As far as valve springs are concerned current belief is that you should only go strong enough to do the job. Heavier springs only increase wear on the rest of the valvetrain, which is fine if you are going to be in the upper ranges a lot i.e. racing, "ultimate longevity" is not part of the racers vocabulary. It is not necessary to go with really strong springs if you are just driving on the street. I would tend to go with the cam grinders recommendations. Like someone mentioned not too long ago in an earlier post, all this talk of high revving is largely poopoo...unless as some of the guys are, they are actually using the car for competition of some form or another. If the cam you want is going to be able to build power to say, 6500RPM then maybe you need stronger springs. But if the cam peaks out at 5500 to 6000RPM, then you probably don't. Unless you plan on revving the engine like that a lot.

By Kyle Thomson (24.83.12.187) on Friday, December 17, 2004 - 06:00 pm:

John S. (did you write the other reply as well? I get so confused with people using the same screen names)

"Most everyone who has done the 4-wheel disc swap did not find it necessary to put on a larger capacity master cylinder or a more powerful booster than the 2nd Gen parts for that reason"

Now I'm not too familiar with the second gens braking system, but is it close to the first gens? I'm running this in a 79 wagon by the way, but I don't think I have the original master cylinder in my car. Mine has a single reservoir master, and I thought the wagons were supposed to come with the dual. One of the reasons I'm trying to upgrade this stuff is that with my set-up as it is, I cannot get even close to locking up my brakes. My pedal goes almost to the floor and stops. My guess is that I'm using all the fluid/travel of the master, and still not getting enough fluid for all the calipers. So I figured if I went with a larger bore(more fluid), and larger diaphramed booster(to equal out the pressure loss), then it could fix most of my problems

ps. made a mistake below, legend has a 15/16 or 1" bore, not the 13/16's I stated

By Kyle Thomson (24.83.12.187) on Friday, December 17, 2004 - 05:14 pm:

John: Well the car is gonna be my normal transportation when I get done with it. I wasn't really interested in the brake bias for ease of adjustment, I just figured it would be the easiest way of doing it. Instead of trying to find a fixed valve that would suit my application. Once I have it set, I probably won't be touching it again, maybe on trips if I load up the back. And I figure if I mount it where the lines are right now, I don't really need to lean over anything, unless I'm to lazy to walk around to the passenger side =)

As for the intership goes, I'm not sure if thats the same system we use up here in Canada. Basically we have to find an employer who is willing to send us to school, and then its a four year term, with only 6 weeks of school each year. Followed by the inter-provincial exam which allows us to work everywhere except Quebec. I'm not done though, I only just wrote my final test for the first year today actually, but I think I'm at about a 94% average, top of the class yay =)

By John S. (68.92.140.5) on Friday, December 17, 2004 - 05:09 pm:

Just a side note here, bigger is not always better. One of the most important factors is point of lockup, and this is determined by many factors not just biasing. Overall braking capacity to total vehicle weight to total tire contact patch etc. There is no point in increasing brake force to the point that you need to wear ballet slippers to be able to control lockup. If you go too big for the sum of all the above factors, that is where you will be. Most everyone who has done the 4-wheel disc swap did not find it necessary to put on a larger capacity master cylinder or a more powerful booster than the 2nd Gen parts for that reason.

By John (67.180.167.118) on Friday, December 17, 2004 - 01:25 pm:

Kyle: For what it is worth, I'd set up the system so that it is easily adjustable. I presume that the point is to maximize braking (i.e. performance driving). The required brake balance will change under any number of factors (basically related to the dynamic wt. on each wheel, which affects available grip, etc.), so I'd make it easy to adjust for these differences. Besides, it is *much* easier to adjust the bias in the first place if you don't need to stop the car, open the hood, lean over the hot engine...

So, what are your plans for the car?

BTW, where did you intern?

By Kyle Thomson (24.83.12.187) on Friday, December 17, 2004 - 12:59 pm:

Well actually I have, my left rear line cracked in two on my last trip down to seattle, I managed to drive it all the way home (3 hours, yes I know it was dumb but it was mostly highway and I didn't use the brakes much) and it never pulled a bit. I thought that was part of the design, if one system leaks, the other system still works, and since its opposite corners it would balance most of the pull out?
Ok well it looks like I might as well switch to F/R, guess I should stop worrying about leaks. So how did you switch your lines over? I'm gonna leave it all under hood, I don't need to adjust it while driving. But how did you run the lines from the master through to the brakes?

ps. I always tend to overthink things, I got in trouble during my apprenticeship for doing it

By Don (199.2.139.188) on Friday, December 17, 2004 - 12:28 pm:

Kyle your making the problem harder than it needs to be. Reduced braking is reduced braking. It matters very little if its diagonal or F/R. You ever drive a car with one caliper working and one failed? It acts like a steering brake!

By Kyle Thomson (24.83.12.187) on Friday, December 17, 2004 - 07:47 am:

Well yes that is true, but could I not just use 2 valves? as long as I make sure each rear brake is getting the same pressure?

something like this --> http://store.summitracing.com/default.asp?target=esearch.asp&N=110&Ntk=KeywordSearch&Ntt=proportioning+valve&x=0&y=0
where as I could just hook it up under the hood and leave it alone

By Don (199.2.139.210) on Friday, December 17, 2004 - 06:25 am:

If you dont use the F/R split you will have to use an non adjustable valve that cant be adjusted to your needs ....which is more dangerous?

By Kyle Thomson (24.83.12.187) on Thursday, December 16, 2004 - 07:55 pm:

the F/R setup? sorry maybe I missed what you are saying. Do you think its advisable for a regular street car? I know its beens used on millions of cars in the past, but I kinda like the added safety of always having some front braking. Maybe I'm just nervous about it as I had a brake line crack in half on me last year.. I tend to get skitish that way

By Don (199.2.139.214) on Thursday, December 16, 2004 - 06:56 pm:

Hi Kyle nope, we allready told you what to do

By Kyle Thomson (24.83.12.187) on Thursday, December 16, 2004 - 07:27 am:

What do you mean? I should just forget about the the proportioning?

By Don (199.2.139.160) on Thursday, December 16, 2004 - 05:50 am:

Kyle your making the problem harder than it is.

By lilbucu (128.208.36.43) on Thursday, December 16, 2004 - 12:17 am:

i am also running 4x100 with rear disks. i would like to know about some options too. i was thinking master cylinder/booster and proportioning valve swap from a modern car.

By Kyle Thomson (24.83.12.187) on Wednesday, December 15, 2004 - 10:21 pm:

hmm allright, what would you suggest I use? I'm running the 4x100 swap, with the rear disc. I'm planing on upgrading my master cylinder and booster to one out of a legend (13/16 bore instead of 7/8 and the bolt spacing is the same) and was trying to figure out what to do with the brake lines. I'd like to have the safety of the daigonally split system, but don't know what to do about front/rear bias. I'm only going on the assumption that I'm not getting enough pressure to run the rear calipers as it was designed to run lower pressure wheel cylinders. I was actually thinking about making up a guage to measure the pressure, I was thinking maybe something that could screw right into the bleeder holes? think that would work? then I could compare it to what the original vehicle pressures are for my specific parts

By Don (199.2.139.183) on Wednesday, December 15, 2004 - 09:55 pm:

Adrian is correct
Its split F/R, same as Adrian runs. I have a Tilton lever type valve it works much better than the other one I used to have.
Side note dont use an adjustable proportioning valve if you wont change the lines on a diagonally split system, it causes bad problems that disappear when the lines are rerun F/R

By Adrian (Evocivic) (203.42.97.141) on Wednesday, December 15, 2004 - 09:09 pm:

Early models are not a diagonal split. The rears and one front are on one circuit, the other front is on another. It changed in around late '76 or '77 (Australian models anyway).

I'll take a guess and say Don is using this setup ... correct Don?

In my car (was diagonal) I changed it to a front-rear split. I've got a dual reservoir master cylinder from a wagon so if one circuit dies the other will definitely still work. It's not the best setup as it's a 50/50 master cylinder so the rears have a bit too much bias (I have to run the bias valve at full front bias). The best way to do it would be with two separate master cylinders and a balance bar between them ... maybe one day.

By Kyle Thomson (24.83.12.187) on Wednesday, December 15, 2004 - 08:55 pm:

Next round of questioning =)
You have an adjustable proportioning valve on your race car right? how did you hook that up with the cars being a diagonally split brake system? did you use 2? or did you convert to a front/rear split system?

By Don (199.2.139.172) on Sunday, December 05, 2004 - 12:59 pm:

Yes I think I can fit a set to EKs too its not hard you just look until the sizes match.

By Kyle Thomson (24.83.12.187) on Sunday, December 05, 2004 - 12:13 pm:

Ya it could have been timing as well, who knows, my carb wasn't tuned well at that time, and the machinest who lightened my flywheel neglected to move the timing marks over (we didn't notice till it was already in the car) so was all by ear at that time. All that has been fixed now, but I haven't got up the nerve to try again, as it was my driver up until recently.
If the springs you found fit the Eb retainers, that means that they are smaller than my El springs right? thats why we were measuring stuff before is that you had some retainers that you didn't know what springs they used? (jackson racing?)

By Don (199.2.139.190) on Sunday, December 05, 2004 - 11:40 am:

I found some springs that will work with the Eb retainers and the Mugen cam. I have my head off right now and after fitment I will post the numbers. In IT the cams are pretty mild (stock blueprint) so I ran a 79 spring and shimed it to gain some pressure. If you engine did that, it almost sounds like a fuel or ignition problem not valve float. Starving the engine for fuel under load can be bad too

By Kyle Thomson (24.83.12.187) on Sunday, December 05, 2004 - 11:29 am:

I'm trying not to thread jack, so I'm starting my own

In the thread about connecting rods you were discussing your rev limit on your race motor and I was wondering if you are using aftermarket valve springs to achieve such high revs? now I know I'm using a different motor (EL) so it's not really comparable, but the only time I've revved it past 6000 it tried to conk out on me, I had to put the clutch in and feather the throttle just to keep it running. Now I'm unsure as to whether that was valve float or if the carb was acting up (Weber DGV), but I've been too scared to try it again as the last thing I want is to bend the valves

Now my question is, what kind of rpm's do you think the stock valve springs can handle? I'm saving my pennies to buy a cam in the spring. They are available locally, and when I talked to them, they had 3 grinds, one near stock, a "street" cam, and a "race" cam. The street cam looked pretty good, as far as tourque is concerned, which is what I would rather have versus a high revving motor with very little tourque. But I'm a little worried that If I change cams, the springs aren't gonna take it. Any suggestions?