What timing setting for /6

I'd like to adjust the timing on my 65 dart. 225 /6. (1977?)

The original repair manual says to set to 2.5. I think it was BTD but it could have been ATD. It's in the book I'll relook it up before adjusting it. However, the tab with the marks on it has 10 and 5 painted on on the other side of TDC from the manuals setting from a previous owner. and when reading a recent post at /6 forum. They were swearing by 16! which isn't even on the tab.

http://www.slantsix.org/forum/viewtopic.php?t=27635&postdays=0&postorder=asc&start=75

"The advanced timing comes in handy to complement the fuel correction. I have tried to run around 10 degrees but I get better economy at 16 degrees. It has a little crisper response to the throttle changes. The gentlemen that owns our local carb shop swears that 16 degrees initial is the ticket for a stock or nearly stock slant in terms of best mileage."

So how do I know what to set it at? I'd like to go for MPG versus power.

Set as much intial timing as you can with out pinging under load. IE pulling a hill in drive or hammering on it in 2nd. I think I'm around 12 degrees BTDC intial and I get 22 mpg out of mine. You get more power and better mpg with as much timing as it will handle. Run a colder plug then the book calls for too. It helps a bunch. I cant remember the number on my Autolites but compared to a Champion heat range it was around 12. The ones they call for in the book are way too hot. You'll get lots of dieseling on hot days at shutdown. And premature pinging from the hot plugs.

If you dont have a dial back timing light just get a elcheapo Summit brand timing tape for a Mopar 7 1/4" dampner and you can then set it with your standard timing light and also check the total timing at 3000 rpm. The summit tape is around $4. Might be able to find one at your local parts store too. Has to be for a Mopar though. Your total timing should end up somewhere between 34 and 40 degrees I'd guess.

If you really want to get fancy you can weld the advancer slots partially shut. Then you can run a ton of initial and still limit total to keep out of ping.

I normally ran at least 15 initial on a street car. Setting it by the book will really make them doggy.

Thanks for the answers. I have a few quick clarifying questions.

BTDC is advanced timing right?
ATDC is ? timeing

is initial timing the timing at the warmed up "curb" idle?

What is and how do I check total timing? is that just reving the engine to 3000 and checking the timing?

I didn't know that timing changed with rpm. if so that must be why adjusting the curb idle first is important.

"dieseling on hot days" is that where the car continues to run even after turning it off? I thought that was a sign of a vacuum leak though of course more than one thing can be a cause just confirming my old logic.

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Thanks for the answers. I have a few quick clarifying questions.

BTDC is advanced timing right?
ATDC is ? timeing

is initial timing the timing at the warmed up "curb" idle?

What is and how do I check total timing? is that just reving the engine to 3000 and checking the timing?

I didn't know that timing changed with rpm. if so that must be why adjusting the curb idle first is important.

"dieseling on hot days" is that where the car continues to run even after turning it off? I thought that was a sign of a vacuum leak though of course more than one thing can be a cause just confirming my old logic.

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Before Top Dead Center BTDC

Dieseling is running on a few seconds after you shut off the key

Intial timing is the timing you are setting while idling warm.

Yes the timing changes while its running. Through your vaccum advance and internal mechanical weights. If your unfamiliar or uncomfortable checking total timing just set the intial timing at 10 degrees BTDC(which is what the timing tabs on the engine are marked in)like normal and keep increasing it a degree at a time till you reach a sweet spot for your application. Of course after each adjustment you need to drive it awhile to see how it does on the road not just idling in the driveway. Or set it at 10 to 15 degrees BTDC and forget about it you'll be close enough.