Further improvements to Lionheart's charging system.

Since the details given in previous pages were completed a few other modifications have been made. I wish I was in a position to just complete the thing but work often gets in the way, as usual !

Firstly the pulley ratios have been changed driving the alternator and I've also moved over to a twin belt arrangement.

Previously the alternator was driven with a single 13mm belt. Crankshaft pulley being 12 inch and the alternator pulley being 2 3/4 inch. This gave around 120 amps at cruising RPM but fell off to around 40 amps at the previous tickover of 400 RPM.

Some work on the engine resulted in much smoother running of the engine with the result that tickover has now been reduced to 360 RPM. Of course this reduced the tickover charge rate from the alternator !

Now a 12 inch alternator pulley driving a 120 amp alternator fitted with a 2 3/4 inch pulley really is about the limit for a single belt. Some people say 60 amps is the limit but this can be pushed if the pulleys are PERFECTLY aligned and the tension is correct. However to go in excess of this will surely result in very rapid belt wear.

The solution has been to go to twin 10mm belts, a 14 inch crankshaft pulley (the biggest room will allow) and a 2 3/8 alternator pulley. This is now giving around 60 amps charge rate at tickover.

I still want to increase this and the next modification is to have the alternator pulley turned down as small as is physically possible in relation to the strenght of it and the hole through the middle. It's looking like we'll be able to get it down to around 2 1/8 inch which should give around 80 amps at tickover. I can live with that.


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