A number of Bugeye owners have suggested switching the original 4.22 rear differential for a 3.9 differential from a later Sprite or Midget. We located a 3.9 in North Carolina. We had it checked out by Glenn’s MG in St. Petersburg. He installed a new pinion oil seal and set the pinion pre-load to factory specification. We cleaned up the pumpkin and painted it with silver caliper paint from POR-15.
The Episode Eight video provides details on the 3.9 differential installation and background.
Trying to use a timing light to set ignition timing is extremely difficult given that the pointer on the timing cover used for alignment with the notch on the crank pulley is at the bottom of the engine.
Tom Colby at Speedwell Engineering https://www.speedwellengineering.com/ignition-timing-pointer-kit/ makes a stainless steel pointer that can be used to move the timing process to the top of the pulley. This is from the Speedwell website:
A duplicate of the 1968 Works BMC Le Mans timing pointer makes for timing the ignition system much easier by moving it to the top side of the engine. The Polished Stainless Steel Pointer (with a flanged nut installed, eliminating need for washers!) is easily installed by removing a timing cover bolt and installing it in place of the bolt. Once top dead center is achieved, just apply the adhesive backed laser-etched stainless steel timing tape to the crankshaft pulley and you’re ready for precision timing with a timing light. Complete with instruction sheet. 100% Made in the USA
This is a short video showing the installation of the ignition pointer. Installation required draining the coolant and removing the radiator.
We always wanted to use the original cover for the gearbox shifter because it just seems so uniquely Sprite/Midget. However, we installed a Datsun 210 gearbox so we had to use a leather boot since the gear shift fouled against the cover.
We were able to purchase what we believe to be the last quick throw gear shift assembly that Gerard Chateauvieux (Gerard’s Garage) fabricated. This will give us the benefit of the short throw or shifting and we should be able to use the original cover. Gerard’s kit is very nicely machined.
The Episode Four video shows the shifter conversion
Leather Boot used with 210 gearbox shifter
Original Cover with Gerard’s Gear Shift