Single point conversion.

[toglhot]

Single points conversion. I've converted the twin points system to a single points system. To do this I manufactured a dual ramp cam and a single points backing plate with a lube bushing. I drilled the points bucket at top to route the cable to the coil under the tank, bought a dual outlet coil, made a bracket for it and mounted it to the original coil mounting frame tab.

The cam proved a little problematic: I turned down a bit of stock to 18mm, filed two ramps on it, then cut the keyway, no luck, timing was was way off. I made a few of these but couldn't get the keyway in the right place. so, I decided to do it in reverse, cut the keyway first, mount the cam, turn the engine over to the firing mark, mark the points heel position on the cam and file away. Then turn the engine over 180degrees and do the same for the second ramp. Super easy this way, I got the timing extremely close for both cylinders with the same dwell as the original cam in very short order. Later, I finessed it a little to get it spot on.

These cams were available from a number of outlets, but apparently they weren't very accurate, so most outlets no longer carry them in stock.

The first two pictures show the timing for for numbers one and two cylinders, using an LED timing light I put together.

 

[Modern Garage]

That's great. It's nice to be able to replace points without spending half a day getting the timing even between the two cylinders. I remember tapping on the end of the point cam on my BMW's to bend the camshaft and get the timing centered.
I've always wondered if the factories used twin points to increase the dwell and saturation on cheap coils or because the point springs couldn't withstand the faster action.
Joe