Tuning a 426 Hemi

[MopSquad]

New Hemi owner here.  I have a '70 Cuda with a '70 Hemi dual 4 bbl Carter.  Some basic questions.

1) Where is the timing pointer?  I can see something (metal bracket) on the passenger side and when I put my timing light on it, I see a line on the damper slightly offset to the metal bracket.  There are no timing marks except for that line on the damper

2) is there a good reference for tuning these Hemi motors. From carbs to timing etc..? I see some rebuild and modify books.  Just need the basics.  The shop manual is confusing and non specific. (covering all Plymouths and engine options)

3) The motor now has a slight dieseling (run on) and a puff of steam?, comes out of the carbs - Is it bad gas? timing? other?

That's a good start  LOL - the car runs great, starts great - just want to learn more and figure out the run-on issue.

[RzeroB]

You're in the right place for the timing scale. The scale would be either spot-welded to the cover, or a separate bracket held on with two bolts. There is usually a tiny hole through the "zero" line for reference. Sometimes the scale lines are not very deep and can easily be obscured by a little dirt or grease. Is yours clean and you still can't see any of the scale lines?

As for the dieseling, do you have the idle stop solenoid installed and is it working? It's on the left side of the carbs inside of the throttle linkage and works with the aft carb. The plunger extends when the ignition is on and retracts when the ignition is off making the throttle plates close completely to prevent dieseling. To properly set it, with ignition off, you should back the idle stop screw completely off making the throttle plates completely close. Then screw the idle stop screw in just a bit so that the throttle plates don't "stick" in the bores. Then start the engine and adjust the idle screw over the solenoid plunger to achieve the desired idle speed. With it set this way, when you turn the ignition off, power is removed from the solenoid and it should retract allowing the throttle plates to completely close thus preventing the dieseling and run on.

[Finoke]

Check your idle speed. Deiseling/ run on could be as easy as lowering your idle speed.

[barnett468]

You're in the right place for the timing scale. The scale would be either spot-welded to the cover, or a separate bracket held on with two bolts. There is usually a tiny hole through the "zero" line for reference. Sometimes the scale lines are not very deep and can easily be obscured by a little dirt or grease. Is yours clean and you still can't see any of the scale lines?

As for the dieseling, do you have the idle stop solenoid installed and is it working? It's on the left side of the carbs inside of the throttle linkage and works with the aft carb. The plunger extends when the ignition is on and retracts when the ignition is off making the throttle plates close completely to prevent dieseling. To properly set it, with ignition off, you should back the idle stop screw completely off making the throttle plates completely close. Then screw the idle stop screw in just a bit so that the throttle plates don't "stick" in the bores. Then start the engine and adjust the idle screw over the solenoid plunger to achieve the desired idle speed. With it set this way, when you turn the ignition off, power is removed from the solenoid and it should retract allowing the throttle plates to completely close thus preventing the dieseling and run on.

xlnt info and good description

[MopSquad]

Thanks for the input.  Here is a pic of my carb setup for you to examine.  I believe there is an idle stop solenoid installed. I'll post a pic of the balancer for you to look at as well.  Wondering what the back flow puff of smoke is when I shut off the motor after is diesels for a second.

[RzeroB]

Looks like the solenoid is installed right. Check to see that it is getting power and working correctly as previously described. As for the "puff" I think that's kind of normal when the motor diesels a bit - it's not running so there isn't any vacuum to pull it into the engine.