PROJECT MGB GT

Rob tries to tweak and fine-tune our MGB GT’s B-series OHV engine, but it’s one step forward and two back at times.

After the last-minute calamities in the January issue of Classics Monthly when our MGB GT was coaxed back to Rob’s home with a sticking throttle cable, he had ticked off a major oil leak problem, but the engine was far from running sweetly. As you’ll see throughout the 17 investigative steps we’ve outlined on fixing the sticking throttle cable, it was caused by the outer sleeving being incorrectly located at the engine bulkhead, but it took an hour of working through several checks to finally get to this point. On the plus side, at least Rob now knows a little more about fixing sticking throttle cables. In fact, the last time he had to deal with such a problem was on the M25 in another MGB, so maybe he’s jinxed.

Other jobs this month have been equally frustrating. The tappets sounded a little noisy, so Rob got stuck into checking the valve clearances, only to discover it wasn’t quite so straightforward to turn the engine and watch for a valve spring to become fully compressed. Rocking the car in gear gave him a thorough workout and almost helped, but his uneven driveway made it tricky. After checking and adjusting the tappets (and there were a few that needed adjusting), they sound better but not exactly silent. Still, they do say a noisy tappet is a happy tappet!

The final job this month was to check the ignition timing. Typically, this didn’t go as smoothly as hoped, with the static timing technique giving some puzzling results. Rob suspects the electronic ignition module is to blame, causing the low-tension wire to the distributor to be permanently live. Luckily, he managed to use a timing strobe with the engine running and successfully adjusted the ignition timing. Now, all he has to do is fix another fuel leak that he spotted while doing this job.