Accel Dual Point Advance Question

Scotty's 52 F3

Scotty's 52 F3

Well-known member
I got a couple old Accel Dual Point distributors for next to nothing so I adapted one to my 52 8RT.

I'm having issues finding the right springs to set up my advance. The springs that were in the Accel to start with are the lightest I have. I'm only running one at the moment and the advance doesn't start to come in until 1100 RPM. Anybody have a recommendation for a source for some lighter springs? The other springs I have are from old advance kits I have and are heavier.

When I set initial timing using a vacuum gauge, max vacuum @ 500 RPM then back off and drop 1", my initial is 6 deg advanced past timing mark. Starts fine.

The max centrifugal advance is 25 deg, all in by 2000 RPM but, doesn't start coming in until 1100 RPM.

I still have to dial in the vacuum advance. Just checking as is gives me 10 deg. 16 deg @ Idle and 36 deg @ 2500 RPM, No load. I can mess with that after I get the springs worked out.

I only hooked up one set of points and gapped @ .014. I can hook up the other set but, my engine is stock. Keeping it simple.

I know I can buy a distributor from Bubba's but, this is part of the fun.

Scott
 

Attachments

  • P1050497.JPG
    P1050497.JPG
    201.7 KB · Views: 33
  • P1050496.JPG
    P1050496.JPG
    118 KB · Views: 28
  • P1050493.jpg
    P1050493.jpg
    35.7 KB · Views: 34
  • P1050494.jpg
    P1050494.jpg
    36.3 KB · Views: 28
  • P1050495.jpg
    P1050495.jpg
    44.3 KB · Views: 28
Last edited:
Scott , I love it when a plan comes together.

The accell is a good choice...

Start with a light and a heavy spring. You want the light spring to run the advance curve on the low rpm side...Bend the tang until the heavy spring has slack in it so the light spring can work. The advance shold be limited to approx 22-24 degrees at 2500 rpm.
I would suggest using the dual point configuration as the single set up is somewhat diffucult to set up as one set makes the circuit and the other set breaks the circuit, The make set times the rotor and the brake set controls the actual coil build up etc. Much more functional this way...
Vacuum and mech shouldnt be over 24 degrees engine timing.anymore and you are just removing horse power.
let me know if i can help the project in any way,,,
 
Thank you Jim. Do you sell the springs I need? The ones I have are too stiff. I only have one spring in and it still doesn't advance until I hit 1100 RPM. It's the lightest spring in the bunch.

Once I find some springs that will allow my advance to come in sooner, I think I can get the rest.

Scott
 
BUBBAS IGNITION said:
Scott , I love it when a plan comes together.

The accell is a good choice...

Start with a light and a heavy spring. You want the light spring to run the advance curve on the low rpm side...Bend the tang until the heavy spring has slack in it so the light spring can work. The advance shold be limited to approx 22-24 degrees at 2500 rpm.
I would suggest using the dual point configuration as the single set up is somewhat diffucult to set up as one set makes the circuit and the other set breaks the circuit, The make set times the rotor and the brake set controls the actual coil build up etc. Much more functional this way...
Vacuum and mech shouldnt be over 24 degrees engine timing.anymore and you are just removing horse power.
let me know if i can help the project in any way,,,
Click to expand...
I believe you can benefit with more spark advance at part throttle. I think 22 mechanical is a good number to shoot for, but I would add at least 6 deg vacuum advance. If your carb is functioning properly, your part throttle will be on the lean side and you need more spark advance under these condition.
 
Thanks for the feedback flatjack. I'll put the other set of points in as per Jim and limit the vacuum advance a bit.

The vacuum can on this one does not have the adjustment screw some have. It looks like it is limited by a tube inside the spring. Easy to install a shim or longer tube.

I still need some lighter advance springs if anybody can help me out with some.

Scott
 
Referring to a mild engine and street application the mechanical advance should be controlled to about 16 degrees. All this mechanical advance should be "in" by 2000 RPM. Usually about 6 degrees of vacuum advance is the limit. The vacuum advance will serve to improve idle as well as light load cruise efficiency. Static advance of about 4 degrees is a good starting point.

In a couple of examples I have made springs to suit my needs. It is not overly difficult to do. You can too.
 
Last edited:
JWL, Thanks for your input also. (And your book) Guess I'll be making up some springs. Never did it but, I'll figure it out. At least now I have a plan!

Scott
 
Just a follow up. I put the 2nd set of points back in as per Jim. Tweeked a single advance spring to get me by until I get some springs from Jim. Starts to advance about 900 RPM now with all in by 2000 RPM.

Set static timing as per JWL to 4 deg. I have 18 deg of mechanical advance and limited my vacuum advance to 6 deg. Starts easy and idles smoooooth. Better throttle response. I thought I had an accelerator pump issue but it no longer stumbles off idle. Drives great and no ping.

THANK YOU everybody! The Accel dual point may not be the most desirable distributor but, it was almost free and a fun project.

Thinking about converting a small block MOPAR electronic one next. Anybody know if a Ford Duraspark is an option?

Scott
 
You must log in or register to reply here.
Back
Top