PCM Timing Question

[Topaz1976]

Have two PCM 5.8 Ford Windsor’s in my boat and I have been struggling to find the total advance timing and what rpm its at. They are 1999’s and 260hp models with prestolite electronic distributors. Any help would be appreciated .

[NautiqueJeff]

10 BTDC at idle, according to the manual. Not sure what the max high speed advance should be though.

[gun-driver]

With 10* BTDC you should see 34* all in.

[NautiqueJeff]

How did you determine that? I have always wondered with the high-speed advance should be on these engines. Is this just from setting the idle advance and checking it at high-speed to see what you've got?

[gun-driver]

Yes
here is a base line that was posted on CCF

Edit : may be different just noticed the OP has an electronic distributor but should be similar

Speaking of numbers, for whoever cares, here's what I came up with for the PCM heavy spring and a Hillman #119 installed in a clip down cap distributor. RPM advance 500 0 plus initial 1000 4 plus initial 1500 12 plus initial 2000 16 plus initial 2500 18 plus initial 3000 22 plus initial 3500 24 plus initial 4000 26 plus initial won't go any higher because of the slot length in the advance plate (also referred to as the stop plate at times) limiting the advance. Now these were with my tach which may read different than your tach and my eyeballs which aren't your eyeballs but they give you an idea of the timing curve with the springs mentioned above. Some people may like it, some may not, but I think it's pretty good keeping in mind that with the heavy spring you don't reach full advance till about 4000 rpm as it originally came from the factory. The engine runs good with this setup