sr2

Great little video but if I may, a few comments. I'm not sure where the '900 to 1200 psi' came from, it's a meaningless number unless you're taking into account total swept piston area, pad area and compound, rotor diameter, etc. (I've seen 2,500 plus psi on many occasions). The choice of master-cylinder diameter is not simply one of how hard of soft you want your pedal to be, the critical issue they failed to address is one of pedal travel and in some setups not getting a pedal at all! Bottom line is if you reduce master-cylinder size you increase pedal travel; a soggy feeling pedal that only firms up close to the floor is anything but ideal. There is a good reason why the majority of cars produced 50 plus years have had servo assisted brakes. Until recently (when we have access to ABS systems that are comfortable in a completion environment) I've always run non assisted brakes in our race cars. It's a very fine line between a firm enough pedal, minimum pedal travel and sufficient front/rear hydraulic pressure but we achieved it with a lot of track testing, a spares kit with a selection of master-cylinder sizes and a service crew that could swap them out in a 10 minute service stop. IMO (for a street car) removing the booster from a standard braking system and reducing the master-cylinder bore with the expectation of retaining sufficient braking and pedal firmness will probably end in tears. To put some figures on the equation a VH44 increases boost by an approximate factor of 190% a VH40 300%, achieving the same amount of unassisted braking would involve 2-3 times the amount of pedal travel. Yes a tandem master-cylinder is a great way of adding redundancy to a braking system but bear in mind (if running a booster) if you have no firewall space to run the standard Mastervac you’ll need to fit two VH44 Hydrovacs to retain brake proportionality.

Although going from a Mastervac type booster to a Hydrovac type is a step back in time , performance and reliability by the look of your overcrowded engine bay it's your only option. Both the VH40 and VH44 share the same crack crack pressure of 35 psi and runout pressure of 450 psi so under normal driving conditions there shouldn't be a huge difference in driveability and feel between the two. Early single circuit disc/drum combo's were always a compromise between the low pressure high displacement requirement of the drums and the high pressure low displacement of the disc calipers i.e. they tended to run smaller diameter wheel cylinders for the drums and bigger caliper pistons (remember with a single piston floating type caliper you need to multiply the piston area x2). All this considered I'l go for the VH44 option Just remember with a single circuit Hydropower system there is no 2nd chance; a failure of either the pushrod seal or or a failure of the circlip that holds the assembly in place leaves you with a pedal that goes straight to the floor. Don't take any chances with 2nd hand units unless you strip, inspect, and assemble with a new kit.

Hi, I need a little more information. What car are we talking about, how standard is the braking system and why do you want to fit a remote booster?

A good step in the right direction, do they have a chapter on the use of composites?

It's quite common on many cars, including those with ABS. Static pedal creep (within reason) is nothing to be concerned about.

Love your work mate, what a project!

On closer inspection the decision was made that the pitted exhaust valve stem was not going to be an issue, (Holden 6’s are not known for loosing valve heads) and that for the time being we’d run with the existing original Yella Terra valves. A light skim……. Valves & seats faced and lapped……… The Y/T Double valve springs were within spec so it was reassemble with new frost plugs and valve seals. I even shouted the old girl a new set of stainless manifold studs and brass nuts, the obligatory yellow paint will come later. And one more job is ticked off the list…...

I'm enjoying you thread immensely. After 25 plus years of building and co-driving race cars it makes me want to stop running our currently overly complex high-tech sponsored car and get back to basics and start all over again. (What I'm really saying is your enthusiasm makes me feel bloody old! ). Watching the in car video's you're making some very obvious mistakes that result in your car controll being jerky & indecisive rather than the smooth but aggressive driving technique that makes a car run fast. I'm picking you've got great potential as a 'peddler' (your time at Levels confirms that) but you're at the stage when you need track time with an experienced person in the passenger seat teaching you the basics and pushing you very hard to be decisive, and in controll. If you were in Auckland I'd be volunteering my services, I'm by no means an expert but I have had the privilege of working beside some very experienced drivers over the years and can see how easy it would be to tweak your driving skills up to the next level. Try your local car cub or even just approach people on track day and ask them if they know of anyone who can come out for a few laps and give you some pointers. Look out for teams using track-days for car testing, you'll find most are approachable, (as you've probably already discovered petrol heads are a friendly bunch). Please don't take my post as being condescending, I'm just an old bugger with a bad habit of calling a spade a f***ing shovel. I'm also impressed with what you're doing. Cheers, Simon.

Yeah Wayne's a bit of a character but he sure knows his stuff, paticuarly with older engines. He just rebuilt a 302 for a mates 68 Mustang restoration, it wasn't cheap but it's one sweet little motor.

Dropped the head off at a local engine reconditioners to have the valves and seats machined. An engine shop with an EIP Vauxhall parked out front, a Model A chassis poking through the roller door and a Mk 1 Zephyr on the hoist has to be oldschool all the way. It’s not hard to spot they’ve been building engines here for 33 years (and it shows!).

It's a simple single diaphragm mastervac, diagnosing the problem would take only a minute with the booster out of the car and possibly 3 with it still installed. I'm suprised you weren't given a more accurate quote; good to here it all worked out well.

Sadly the only way to successfully run a roller on the 'drive' (i.e. tension) side of a chain drive is to use a sprocket as an idler pulley. It will need to be running on an idler shaft with bearings. Love your project however, good to see a fellow convert of the electrolysis rust removal method.

The product you want is called Tergophos. I buy it from Target Cleaning Supplies. It's by far the best Phosphoric based product for rust removal. http://www.targetcleaningsupplies.co.nz/html/chemetall.php $54 for 5 liters is great value for money (you then dilute it with water).

I've had good results with electrolysis for rust removal. See page 2 of my build thread for a description and pic's. //oldschool.co.nz/index.php?/topic/49842-sr2%E2%80%99s-1947-vauxhall-%E2%80%9Crigamortice%E2%80%9D-build-thread/

Sometimes you just get lucky; I managed to score an old set of unused shaft mounted Yella Terra roller rockers for only $300. There was some confusion from the seller as to what head they would fit and I got away with the lowball offer from hell....... Although being the right ratio I was after (5:1) they were the later pedestal type mount as opposed to the earlier stud mount (i.e. my YT head). I’ve always felt that stud mounting roller rockers was a half-arsed compromise; I was always uncomfortable with how they twist so much you have to run pushrod guide plates. The solution was to get a local machine shop pull out the press fit rocker studs and machine 32 thou off the pedestals. Problem was I was then left with 3/8” holes to screw the 5/16” rocker mount cap screws into. The solution was to use Recoil Keyserts…….. I drilled and tapped the holes out to 5/16 UNC, turned up a DIY insertion tool (everyone needs a lathe)…… A quick dummy assembly and I’m a happy man……..

Remember to radius the shoes to fit if you're machining the drums.

Hi Ben, sounds like you're well on the way with diagnosing the problem. Remember that boosters are vacuum suspended (i.e. the have vacuum on both sides of the diaphragm at rest) and when actuated introduce the atmosphere to the rear chamber to assist the brakes. I’d put my money on a ruptured main diaphragm, pinch off the vacuum supply line with a pair of vice grips (wrap tape around the jaws to avoid damage) and confirm the engine issues disappear. The most likely cause is master cylinder that is leaking from the rear seal; the brake fluid gets into the booster and eats the diaphragm for breakfast! If the above test points to the diaphragm, pull of the master cylinder and look for signs of leakage and report back.

Hi Ben, I'll need to know what car it's fitted to and then I can talk you through the correct diagnosis. Once that's established we can either fix the fault, buy a 2nd hand replacement part or pass the offending component to a local shop for repair. Cheers, Simon.

Mate, sounds like a great project but you're rapidly painting yourself into a corner. My feeling is that you're delaying the inevitable which is simply fitting a dual master cylinder, adjustable balance bar pedal box. I'm ex the automotive brake industry (worked for PBR in Aussie and APPCO Brake & Clutch in NZ)and have been building race/rally cars for the last 20+ years, all I can say is there is a reason why all low tech (i.e. non traction controll/abs) rally cars run this setup.

I've converted a few and have found it's far easier to hit Zebra, Pickapart etc.and take the whole mechanism rather than trying to adapt a motor to fit.

Bedding in will have taken 3-4 stops from 100K. Let us all know how the new stoppers feel.

Option 1: sounds like the path of least resistance and it just may get you through; a booster would allow you to run far harder linings than standard. Option 2: if parts are available and the conversion is straightforward it would defiantly give you the improvement you’re after. Even older solid rotors have a huge advantage over drums for heat dissipation. If the B1500 and B1600 rear cylinders are the same all you would need to do is use the B1600 master cylinder to get close with brake bias. You’re correct in that you can use 2 Hydrovacs on a split system (BMW did it years back but in my post I said "single"), you just can’t use one on a split system without radically changing the bias. You can also use two dissimilar hydrovacs on a single/or split system as a way of increasing front pressure for a disc conversion (eg a 5/8" Vh44 on the front and a 7/8" Vh44D on the rear). I did quite a number of such conversions in the eighty's, they were pretty trick for the times but to be honest they took up a hell of a lot of under bonnet space, were a bloody nightmare to plumb in and bleed and gave you a very average pedal! Avoid using a ‘proportioning valve’ if you can, most are really only pressure limiting valves and are no up to radically changing brake bias (e.g. going from drum/drum to drum/disc).

Correct me if I'm wrong (haven't been under the bonnet of one for a long time) but doesn't the B1500 have a tandem master cylinder? If it does a VH44 (or any single hydrovac)wouldn't be suitable for boosting the original drums. Have to say I agree with Cletus on this one. Make sure all the hydraulics are in good condition, reline the shoes with medium Padgid compound (or similar) and make sure someone who knows their stuff machines the drums and radiuses the shoes to fit the individual drums. You might be suprised with the result.

For what it's worth in 20 years of building/racing competition cars I've only once ever encounter gas build up issues, the idea that this could be an issue on the street (presuming you’re running good quality pads) isn’t even worth consideration. Our current race car has been reaching temperatures where we are cooking the ceramic buffer between the piston and the brake pad to the point where they are crumbling, and I'm still running non slotted or drilled rotors (still with no hint of gas build up). My feeling is that there is a lot of aftermarket misinformation (i.e.B/S) out there being pushed by 3rd party suppliers. Originally Rotors were only drilled to reduce un-sprung weight, great idea if you’re running a state of the art single seater but probably irrelevant for most other applications. Yes slotting can help control gas build up but unless you’re experiencing it all you’re doing is adding potential stress risers and reducing pad/rotor area per revolution. It would be great there was a magic bullet for rotor selection but there isn’t. The only advice I can give is that you will never regret buying quality components from reputable well established suppliers, (AP, Brembo, etc.).

I'm enjoying your project and your meticulous approach to detail, you're doing a great job of writing it up as well. What's your technique for cleaning aluminium inlet manifolds? (I'm considering sand blasting mine).