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Alternator Mount & Tensioner

The factory Starlet alternator location is behind the engine on the drivers side, however it will not fit there in the Mini so it has to be relocated. The usual spot for these conversions is to have it sit next to the upper timing belt cover and the drivers side inner wing/guard has to be trimmed so that it sits half in the wheel arch.

Other conversions have the alternator that hinges on a single bolt to tension the belt and runs around only the crankshaft pulley and alternator. However because my main spar that runs from the subframe tower to the front of the subframe bends inward (towards the centre of the car when looking at it front on), the belt will foul against this main spar and I had to use an idler pulley to adjust the path of the belt. The following pic will explain. I chose the smallest flat pulley I could find - 50mm OD.

The main mount bracket is made from some 5mm flat steel and 20mm round tube bolted to the original power steering pump location.

It's not shown in the pics, but to ensure the crankshaft and alternator pulleys were aligned correctly I clamped some flat steel bar vertically to the crankshaft pulley that ran between the crank pulley and stopped just below where the alternator pulley was going to be. This allowed me to do an quick and easy visual check on the alignment when tack welding, as any misalignment would cause premature belt wear.

The flat idler pulley is a rigid mounted and rotating the alternator upward tensions the belt (known as a swing tensioner). Both the brackets for the idler pulley mount and the curved tensioner bracket have been welded directly to the engine mount. The curved bracket is an original tensioner (although I'm not sure whether it's from the alternator or something else) that has been trimmed and welded on, although since this pic was taken I've added some small triangular gussets at the bottom of the curved bracket to better transfer the vertical load onto the main engine mount.
Post Edit from a few months later... Once I had the engine fitted in the shell, I found the alternator mount did NOT interfere with the headlight bucket. The alternator body clears it by about 10mm. Phew!

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