440 Timing

[clazar]

I have a completely stock 70 440 +6 auto RR with Chrysler electronic ignition. Right now the timing is set at 8 initial advanced. With the vacuum line off & plugged I think it's about 20-25 advanced at 2500 rpm. Should it be higher or should I check it at 3000 rpm ???



Chuck

 

[benno440]

8 initial, that seems awfully low, im at 20* initial, with 14* mechanical advance

 

[clazar]

8 initial, that seems awfully low, im at 20* initial, with 14* mechanical advance

I think the factory says 5 btdc. But I know with crappy gas & such, to advance more. I just not sure how much.

Chuck

 

[Rodney]

make sure your vacuum advance is good and the mechanical advance is free of rust and dirt and working smoothly.
hope this helps

Ideally, you want as much initial timing that the engine will tolerate and no more than 36* total all in by 2500-2800 rpm for a typical street build. The speed of the timing curve is determined by the springs on your advance weights inside the distributor. I've found that one light spring & one medium spring achieves the desired results.

 

[clazar]

make sure your vacuum advance is good and the mechanical advance is free of rust and dirt and working smoothly.
hope this helps

Is 20-25 without the vacuum hooked up ok??

The distributor is 2 yrs old. It does advance with the vacuum attached. I haven't checked recently what total advance is. I'll do that tonite.

Chuck

 

[lewtot184]

with a stock mopar electronic igniton (13 degree plate, factory springs) i set the intial at 8 degrees and get a total of 34 degrees around 3000rpm. i ran my best 1/4 mile times with a stock 6-pak with this set-up.

 

[clazar]

with a stock mopar electronic igniton (13 degree plate, factory springs) i set the intial at 8 degrees and get a total of 34 degrees around 3000rpm. i ran my best 1/4 mile times with a stock 6-pak with this set-up.

Are you talking total with vacuum attached or blocked off ??

Chuck

 

[Garys1969RR]

My 451 runs best with 20 initial, and 38 total advance. This is with vac advance hose un hooked. I run the 509 cam, 13.5 to 1 C/R, 100 octane or higher fuel. It has tons of low end torque, great throttle response, mid to low 12s at 110 MPH. But I am at 5600 feet elevation. Try 20 initial, 38 total. Back it off a little if it pings. Every situation is different. After I set my timing, I hook up the vac advance hose and it runs really good!

 

[mopar 3 B]

8 initial, that seems awfully low, im at 20* initial, with 14* mechanical advance

What are you doing to get it to start? I have found anything over 15* initial is way to much for the starter to overcome once the engine has warmed up. Are you cutting ignition back until the engine is spinning?

 

[lewtot184]

What are you doing to get it to start? I have found anything over 15* initial is way to much for the starter to overcome once the engine has warmed up. Are you cutting ignition back until the engine is spinning?

stock or near stock cams with near stock compression don't like a lot of intial timing, as you may have found out. they make too much cylinder pressure down low. i only due 8 degrees to get the total i want. a stocker will work ok with a little less.

 

[62 Dart Convertible]

Are you talking total with vacuum attached or blocked off ??

Chuck

Figures on initial and total advance are always quoted/checked with vacuum disconnected.

 

[Meep-Meep]

With vacuum line off and plugged you should have about 38 total. The initial is about right with a stock cam but I have run more. Run it up to at least 4000 RPM to make sure you are all in advance wise. 38 deg all in by 2500 is a good start.