Re: 262 Vortec V6 timing issues, sorry a bit long
F1 engines, apple and oranges...
Otherwise, all discussion aside, the bottom line here imho, is how to get the most out of it without tearing it up or spending six months playing with it.
Any engine with a given fuel is going to "like" a little different timing. once you have jetting close, you can tell whwther it is right or not by where the color change on the electrode (the "timing line") is. It should be right at the bend. closer to the plug base, needs less timing, closer to the tip, needs more timing.
1. Look at the plugs - color, is fuel mixture on target. timing mark (might be hard to tell after changing it around a lot..). I'm assuming fuel is right.
2. Fill the tank with the lowest octane fuel you ever plan to run in it.
3. set timing at conservative merc setting, and do a wot run, write down rpms and speed (gps is far better, make sure going same direction if in a river, etc...), once you trim it out for the first run, don't change trim or weight distribution in boat, etc... want every run to be a representative comparison. make sure engine is good and warm on first one too...
4. walk timing out more advanced 2 degrees at a time noting wot rpms and speed each time.
5. when it pings or when speed stops increasing, retard 2 degrees and leave it there.
6. see that idle and accelleration are good with that initial setting. if no, then consider a different module, but I'm betting they will be fine. I'm also betting you wind up with more than 22 and less than 34 total advance...
7. Run the crap out of it for a little bit and check the timing mark on a couple plugs to see that they're where you want them. (at the bend in the electrode...).
8. and finally, enjoy it without worrying about it for a while...
Hope this is helpful!
ps. You're going to want rpms and wide open throttle to be right at the peak of max horsepower for the engine. I'm guessing based on the numbers you posted above that you're propped right and that you'll wind up at 4600 to 4800 rpms with the boat loaded lightly...
also, you can tweak a bit more out of any engine, by running a litle cooler thermostat, a little thinned oil (not super thin!), running high octane fuel (allows for more timing advance) and leaning it out as far as possible without getting so lean your exhaust gas temps start going up. The problem is if you set your engine up this way, after a while, something is going to be a little off, or you'll get some crappy fuel, etc... it'll detonate like crazy, burn valves, or maybe even eat itself... even if you don't have a major problem all at once you could seriously shorten its lifetime... and no by the time my previous 4.3 was done, it was not stock and the timing was not more advanced than 22 degrees... Just my two cents.
