With 95,573 miles on the odometer and not a prayer of a new inspection sticker when the current one expires at the end of April, the Blue Winter Beater GT is truly approaching the finish line. It was something of a surprise, therefore, when after a stop at the Westminster Post Office en route to Abingdon Spares, the car resolutely refused to restart. No matter, Steve and I winched it up on the trailer, scooted over to A.S.L. and then rolled the car into the downstairs workbay for attention by the late shift.
These later MGB’s run a ballasted ignition system, which means that the coil operates on a current of less than 12 volts. A coil, being nothing more than an electrical transformer, jumps the voltage up to about 30,000 volts at the plugs, and for reasons not worth investigating, the ballast had failed. Oh, well, technically the engine would catch, it just wouldn’t stay running.
A ballasted ignition allows you to play a useful little trick on the coil. A second feed from the starter solenoid which is only live when the engine is cranking, creates a much greater momentary peak voltage, that’s why it would start and die. A close inspection of the first picture will reveal my long obsolete Fluke 73 multimeter, a vastly more sophisticated diagnostic tool than the technician using it, and the repair, which was to install a used 12 volt coil** and run a jumper wire to it from what we call the “Green Fuse”, which is for functions, like turn signals, which are switched thru the ignition and fused.
Butch has had to do a large amount of custom fitting for the Healey Blue over Old English White BJ8. If you’ve been reading this column regularly, you’re aware that this car is running an Australian-made DMD intake manifold which comes with some rudimentary throttle linkage, and not much else. Because the standard carburetor heatshield simply won’t fit it, Butch made up what is actually a two piece heatshield with a “Cool Mat” insulator sandwiched in between.
The DMD-provided linkage pulls from the bracket with a return spring at each end which is bolted to the intake manifold. We didn’t like that because there was no way to arrange for adequate thermal protection for the carburetor float bowls. So after much bad language was expressed about the manifold tuner’s engineeering practices, we decided we could do better, and this task of course fell once again to Butch. Here is his solution:
He has notched the top of the heatshield to allow for the cable pull and fabricated a cable stop bracket which is mounted to the air cleaner flanges of the carburetors. This has the additional benefit of using up more of the length of the suppled right hand drive throttle cable, which has a clevis at both ends. Unfortunately, this is making for exceedingly tight quarters for the air cleaner assembly, but if push comes to shove, we can always make the same sort of expedient repair I once saw performed on a well turned out Allard on the Bonneville Salt Flats during Speed Week. In order to increase air flow to the radiator, the pit crew simply opened out the front shroud with a pair of tin snips. We have tin snips. – Click to Enlarge All of These Pictures-
** A number of years ago, Peter Egan, writing in Road & Track magazine detailed ten steps guaranteed to make your race car go slower, one of which was to “borrow a used ignition coil from one of your competitors”, although a much better method, in my judgment, was “to wait until after the starter’s flag drops to remove the tennis balls from your velocity stacks“.