Newtons third law states” That for every action there is an equal and opposite reaction” well I have experienced real proof of this in my MGBV8

When the car had its original 2.0 Li engine I fitted a pair of “tramp rods” to the rear suspension to eliminate axle tramp under maximum load, particularly at the hillclimb off the start line, I copied the tramp rod forward mounting from the Moss Performance Manual which is retained by the spring pivot bolt and 4 ¼ inch bolts through the floor in front of the spring mount.

The tramp rod length was adjustable and formed a parallelogram with the front half of the spring, all was well , I installed the V8 and never thought any more about it until recently when on closer inspection I found the floor was severely cracking where the small screws  were .

Good old Newtons Law was alive and

 well, the V8 produces a heap of torque and this causes the forward movement of the tramp rod with a resulting “bellcrank” action to take place through its mounting and into the floor, shock horror! It wouldn’t have been long before the front of the spring came up through the floor.

After  lots of MIG welding the fractures in the floor and many hours  of fabricating 2 reinforcing channel members and welding them  into the underbody the problem has been rectified, I was not alone with this problem, and when I got on the web I found it’s happened to lots of people, Adrian Akhurst makes a channel to prevent this problem occurring and if you look under an RV8 you will see that its makers also recognised the weakness there and include reinforcing in the area.

The resultant forces are now transferred not only into the whole rear floor but into the cross member further strengthening the body, of course probably none of this would have occurred if I hadn’t fitted  tramp rods.

    Laurie Houghton

ALTERATIONS TO MGB BRAKING SYSTEMS

Circuit sprinting in your MGB ? No matter how fast you can get down a long straight your lap times can be dictated by how quick you can slow the car into the corners, so really good brakes are absolutely essential.

When I started sprinting this fact became obvious so the first brake upgrade took place, the norm at the time was 4 piston Volvo callipers , vented Mitsubishi rotors (about 275mm dia) and some competition pads.

I went down another track with Rover Vanden Plas SDI 4 piston callipers, Peugeot rotors and Race Brakes Comp 3 pads, however once I installed a V8 things changed, speeds at the end of the straights at Mallala were higher so more stopping power was needed.

Out with the DBA disc brake catalogue to find a bigger diameter rotor, the one that met my requirement was for the BMW Mini Cooper S upgrade,

DBA 4000 series wiper slot sport rotor Pt No 2524 294mm dia x 22mm slotted and vented, a spin in the lathe to open up the centre hole and redrill the 4 holes for the wheel studs to the MG pitch.

To get this rotor inside the 15 inch wheels meant fitting the aluminium R32 Nissan 4 piston calipers which leaves about a 1/4 inch clearance between the caliper and inside of the wheel, this also meant relocating the caliper to about the 2 o’clock position on the stub axle by some laser cut adaptor plates, some new bolts, lock tabs, braided stainless steel hoses, Hawk HP+ competition pads and Motul RBF 600 high temperature brake fluid completed the package.

The rear brakes are what most people use, Nissan R31 2 piston callipers and rotors. I still use the standard MGB dual piston master cylinder from the ‘73 model and with the better braking effort in the front no longer need the bias valve in the rear circuit.

Boy does she stop now, and no fade with the hi temp fluid.

By the way you do need really good sticky tyres.

From Laurie Houghton    MGBV8 Spl