Disc brake conversion

[roy mawbey]

Guys,

Over on www.abcgt.com and on the ' recent topics ' page look at the 'disc brake conversion' thread . some really nice fabrication work by Ashley Page. Brembo's used and the photo's seem to show a really good job.

Might be of interest for Steve Wright I think he still has drums but I could be wrong. I will stay of course with drums but they do look old fashioned compared to the set up shown.

Roy

[john ruston]

The GT drums from Pace are same as discs and historically correct.

[mycar]

Thanks Roy.

It was a modification I considered for our car, thinking what could be better than disks all round ? Further reading revealed that disc brakes are heavier than drums, the 'feel' is very different and changes the A driving experience. Not for the better.

I ended up being convinced that in my case drums are best... but slightly disappointed that I don't get to fit shiny bits to each corner.

I look forward to reading the ABCGT article

[Nine One One]

Topic is here
http://www.abcgt.com/forum/6-Hot-Rod--M ... r-356.html

[S.J.Szabo]

Mr.Mycar:

Ever the Slave of Sloth, I simply mounted a set of discs from a C on the Trusty Coupe (a T1 A), lo so many years (and miles) ago, back when and where plentiful swap meets allowed such opportunities.

At the risk of being contrary (a not uncommon occurrence, tho never out of malice), my experience since has been a bit different than your suppositions about disc brakes, tho you are correct that it changes the experience of driving an A all right…

Maybe it’s just me, but I have found disc brakes to be clearly superior in both feel and performance (wet or dry), such that I have never had a moment’s regret for the conversion. And as a bonus, wear parts are still readily available (tried to find fresh drums lately?) and swapping out disc pads is cheap and easy (and no machines are turned on at any time in the operation).

Plus I’m just pragmatic enough to feel that plus or minus a few pounds on each corner of such a crude suspension isn’t worth worrying about in a daily driver. Heck, my 5 ½” steel wheels add more than the discs, tho I could probably get most of it back if I ever get those cookie-cutters on.

I love ‘em.

[mycar]

Thank you S.J., you've prompted me to get round to reading the thread and an interesting read it do make.

I'm unsure whether fitting a C system to my A is a practical proposition these days. Cost and availability.... cost, would probably make it prohibitive, I'm still getting my breath back after the new engine.

However the ABCGT thread does come up with plenty of alternatives, I like the sound of the the CSP system; German, straightforward to fit, well reviewed and pretty reasonable. Lots of ticks.

But then there's Al Zim's and Airkewld... I think further research is in order.

I did start a bit of research this evening. One small glass of Merlot and before I know it I'm down the rabbit hole. One thread leads to 5 threads which lead to 8 threads.... four of which are dual master cylinder threads, I now have 17 tabs and 2 windows open and it's all still making sense..... just.

I like the idea of disc brakes a lot, even if it's just the fronts and I think I might make a move in that direction, though It may be a slow and steady move in that direction. Perhaps next year.

Meanwhile the drums are good, they're better when they're hot and I'm more familiar with them now. Just don't use the hand brake after a spirited drive or the drums will go egg shaped.

[S.J.Szabo]

Mr.Mycar:

I can appreciate the complexities of the decision; when I did mine, it took a while to gather all the pieces, tho I was fortunate enough to have EASY (and the help of the inestimable Mr.Brezeale) right across the bay for the bits that I couldn’t turn up at the swap meets.

My last (I promise) advice I would offer for your deliberate considerations is this:

Go with all four; it gets you clear of all of the drum issues of supply, as well as the unnecessary complication of finding the necessary split master cyl. Besides, the difference in performance is noticable.

Upgrading to the C upright would provide a beefier spindle , as well as the bearings that go with it.

Consider the master cyl. out of a 914; it’s simple, cheap, readily available, and does not add the complication of an indicator light you don’t have as on the early 911s. Also, the simple reservoir can be mounted using existing mounting points.

C model axle tubes provide the accommodation required without adding the weight of adapters, while also providing easier adaptation of the revised emergency brake.

The five-lug hubs that go with the system opens the door to very many wheel choices, none of which require a special adapter to change tires anywhere you go. As a bonus, are the good 911 wheel spacers that fill out the wheel wells while allowing wider wheels and tires, that are not too tough to find. On this point, I would also advise the utilization of the plethora of longer 911 wheel studs widely available.

With that, I will stop beating the drum for keeping things “Porsche ®” and leave you to your ruminations.

One last thing tho… I hope you won’t think me presumptuous to note that I think a hearty Burgundy goes best with disc brakes.

[Mike Smith]

We have fitted a couple of CSP Sets in the past
It was not difficult but they were not the straight `bolt on` that was expected

With regard to using another Master Cylinder, the flange is often thicker than the originals - make sure that you get a FULL Nut on the 2 x bolts holding it into the firewall

As for using a 914 Master Cylinder
From my memory it protrudes too far into the cabin and requires a spacer to be machined BUT with that said there are a plethora of ATE master cylinders that will do the job (maybe there is also more than one 914 M/C) .


We can put at least 3 x complete PORSCHE sets together for anybody that wants them

[Dingbat]

Hi All , this is definitely not aimed at Mr Mycar more a general rant,
At the risk of repeating what I may have said in the past 356's are BLOODY OLD CARS, if you want something with over servoed mush "O" matic brakes, by a new car, and while you at it get someone to puree your food for you so you don't have to go to the effort of chewing. Porsche did a pretty good job of turning out a good all round sports car with simple and to my way of thinking more than adequate brakes, if you want a comparison try a stock Xk 120 or a DB2 Aston, faster in a straight line but they don't stop that well... It is important that a drum braked 356 has its system maintained and adjusted correctly and that the,rest of the running gear is in good shape, many need work and brake drums are an issue, in particular with old B's that seem to suffer corrosion issues with brake drums, much more so than A's, drum brakes do have their foibles , it's not unusual to briefly have one front bake apply before the other, there are four hydraulic cylinders in there but I ha e never had any scarcely moments driving enthusiastically with fairly well loaded 356's , but that is with well maintained cars. Now a C does stop well and the parts are cheaper and easier to source, almost fit and forget, pull the wheel off and there they are, although the hand brake is a little more tricky to get at, if I were to "upgrade" an A or B I would go with the C discs, and that's what my old A had but they had been fitted by a previous owner, and it stopped very well and they had plenty of feel etc and I do like the stock later steel wheels especially five and a halfs on the back, no hubcaps. If I had a terrible project to do and the drums were in really ropey condition and all new cylinders w ere needed I would go all C not some after market stuff, now I know it's not a 356 but I recently did some work on an improved VW Samba van with CSP discs on the front and they were not that effective, I actually think the stock drums in normal use felt more effective, although in extremis the drums may have faded whilst the discs would have remained consistently ho hum.
If arguably better cheaper disc brakes are needed give Mike a call and buy a set of serviceable C disc brakes off him and I suppose some wheels too, though steels are not cheap anymore, and keep it all Porsche, off on a tangent if you want to take a look at one of the ultimate developments of the drum brake take a look at Alfa Rome's triple leading shoe drum drake with their cooling fins machined at forty five degrees, very pretty.
In my many years of hard won experience most people's complaints about their old cars short comings are down to something actually being wrong with what they have rather than a real problem with the original design.
Lastly never ever fit copper brake pipes, good in a house not in a car..

[smallspeed]

..to follow on from that, DO fit kunifer or steel lines! Braided hose is ok in short sections but regardless how expensive hose you use it's far squishier, harder to eyeball for condition, heavier, more expensive (the list goes on) than proper hard lines

[S.J.Szabo]

Rejoinders with a smile....

Mr.Smith: You could be right, as I did not personally scavenge the M.C. However, I am inclined to believe the redoubtable proprietor of EASY as to its origins. And as I recall (its been over 30 yrs. now), I used the push rod native to the M.C. without incident, and achieved full fastener contact without special accommodation.

Mr.Dingbat: I can appreciate the originality sentiment behind you comments, but to my thinking, if all the parts are 356, it's more a matter of "update" than "restomod". The 356 drums (well, the B's anyway) were very capable of course, and look great on a car as it sits in the garage. However, my plan from the start, was to build for use over time, not occasional contemplation. Even in the 80's, it was clear that drums were going to have maintenance issues going forward. This came home since then every time I changed pads and when I easily (and fairly cheaply) replaced my worn-out discs not so long ago.

In the same vein, the 644 was a good enough gearbox, but I run a 741 because it does the job a little bit better. And I have never regretted getting away from skinny "wide five" wheels, even for a minute.

It comes down to one's philosophy of Olde Cars I reckon, and mine is that they only make sense when you're driving them. I figure I've put maybe 125K mi. on the Trusty Coupe (and that number is low because its not the only old crock in the family fleet) and I am looking forward to the next 100K with great relish.

[hot66]

It comes down to one's philosophy of Olde Cars I reckon, and mine is that they only make sense when you're driving them. I figure I've put maybe 125K mi. on the Trusty Coupe (and that number is low because its not the only old crock in the family fleet) and I am looking forward to the next 100K with great relish.

Love your philosophy driving them is where I get my pleasure from too

[Graham]

I have recently put a disc conversion on the front of this 356A special it's a very light car with a lively 912 engine,and was a bit worried that it would be over braked, far from it, the brakes are now absolutely fantastic, also the help of slightly wider tyres on it are a bonus, the owner drives it quite hard and by the time I had sourced a pair of front drums, and fitted all the cylinders it needed, it was a relatively economical decision, and he's still got all those parts in a box.

[mycar]

That looks lovely Graham, what kit did you fit ?

And do you know the colour, that's a beautiful blue.

[roy mawbey]

Mike,

Same colour as my car if I am not mistaken Meissen Blue.

It does look very nice.

Roy