fast camshaft specs

[Henk]

Hi Anders,

Yes, it's starting and running great now. Before that I had a few issues with the engine. After some searching it was because of a dying alternator. When I put the spare in almost everything was solved!  I had some wire connectors on the ignition coil getting loose while running the car. I change the old wire lugs with eye terminals and bolted these on the coil, problem solved.

And of course the right timing helped a lot. I found 10° advanced timing is the best. Above that doesn't work properly. I was advised 12° or more, but that's not working for this car.
For this standard engine the original ignition is fine. And I will rebuild the old alternator red so it can be used on the 2nd engine.

But most important is I can drive the car around. Because of that I found the clutch was slipping, so I replaced that. And I'm still finding little things to do.

For the spare engine injection project I think you are right to mount a 123ignition. I don't think the original will be working the best in combination with the injection and faster cam.
But first I need the injectors, all connectors, make a wiring loom and so on.

To be continued....

[Anders Dinsen]

Getting on the road is great. Problems show up, but I'm glad to hear your's solving it. I'm still working on getting to that point.

10 degrees on the standard cam makes sense. The period is short and there's little overlap on that cam so the fuel mixture in idle is good. You're probably running 800'ish idle? I have mine at 15 with the Holbay cam, which makes for a decent idle at 1100. It's huting a bit, but that's probably due to the high overlap on the cam and my cylinder head - it most likely short circuits a bit of fuel out the exhaust during idle. I have an AFR meter with a wide band oxygen sensor in the exhaust so I know the mixture is correct now.

I considered fuel injection years back. Most ECU's come with some sort of ignition controller and eliminate the distributor as they run wasted spark configurations with two coils. From an engine management perspective, that's a better system. They usually, however, depend on both a crank sensor and a cam sensor, so there's a bit of work involved and it will be completely custom. I'm not going that route, but staying with the sidedraught carbs. There's more performance to be gained by working on the airflow in the head, especially enlarging the inlet valve seat inner diameter. About the original distributors, in principle they can be tuned to do anything by replacing springs with other springs, but it requires a complete rebuild every time you want to try something different. The original Bosch has an advance curve that suits the original cam only (and vacuum takeoff from the original Solex carb). I have used it on my Holbay cam, but it will never be perfect, so I'm going to change eventually so that I can tune it to the cam and head.

/Anders