318 advance curve

[furz4444]

What does everyone here think a good advance curve would be for a 73 dart with a 318 and 2.76 highway gears. Engine is 8.5 compression, running 340 factory HP cam, edelbrock intake with 600 vac seconmdary holley. I am running with timing 8 degrees BTDC and engine runs well , easy starting, and no pinging issues. I plan on running 89 octane fuel. I was thinking on using a MP advance curve kit and just running one of the small advance springs combined with the smaller of the stock springs. Am looking for full mechanical advance at 2600 RPM. I will set my timing for 36 degrees at 3000 RPM without vacume advance. I plan on installing an adjustable vacume advance unit and setting it up so total advance is around 50 degrees. I have installed a timing tape so I can get accurate information. Does this sound like a good starting point for this combination?

[dave571]

I'm not 100% familiar with "stock 340 cam" specs.

What you have proposed isn't bad, curve wise.

I think with the compression as low as it is, and a bit of a cam, you could run 12 or more on the intial. So shorten the mechanical to 24 (24 and 12 is 36) instead of 28 (28 plus 8 =36)

If you had 323's or 355's I'd say to run 16 initial and 20 mechanical, and see if it pings.

[TK]

Agree on the 12 initial 36 total, that is where I like to keep my 318's at.

(With the 2.76 gears, I would not get full before 3000, that is for sure)

[furz4444]

The 340 cam is 210 .429 lift on the intake and 220 .444 on the exhaust, centerline 114. Pretty good idle, you can tell it's not a stock 318 but thats about it. So far the combo is running well. I was thinking the same thing as Truck Boy on the advance curve, with 2.76 gears at cruse RPM, it will be pulling an awful lot of vacum advance. Thats one reason I thought I might find an adjustable vacume advance useful. I don't want to run without it as I drive this car about 5000 miles a year and have allways got pretty good mileage even with a very tired motor.