Hello dear Olds guys.

I'm wondering if someone knows the factory timing figures for the various engines over the years? All the way from '64 to '90. Did they vary with compression? Did they vary with bore size? Did they vary with cam size? With wildaboutcars.com being pay-to-use, the info is not readily available.

Like so:

Engine CID:
Compression:
Bore:
Initial timing:
Total timing:
Vacuum advance:



Background:
I've recently acquired a 403 HEI for my 380 stroker engine, after my Chinesium HEI broke its advance mechanism.

Knowing a bit of combustion theory, I thought I'd try to figure out what the actual optimum timing is for my engine. The stroke, compression and bore has been modified, meaning that it doesn't necessarily need base 350 timing numbers. Ultimately I'd like to dyno tune the distributor - but that's down the road.

Thanks.

 

The advance curves for each distributor are listed in that year's Chassis Service Manual.

 

Yes, and I only have a 72. They used to be available on wildaboutcars.com, but nowadays they're behind a pay wall.