Do I need to recurve the dizzy?

[69F100]

I have a stock Autolite dizzy that came in the 390 when I bought the truck and was wondering if I need to have my dizzy recurved or just go out and get a rebuilt one. I recently got the Pertronix Ignitor 2 module to replace the points. I'm also considering getting an MSD dizzy with the male ends on top of the cap but don't know if it's worth it to get one of those. I don't plan on racing the truck at the strip but I do want it to have a spark distribution system that'll keep me ahead of the rice burner kids in town.

[heep70]

The Pertronix should be just fine. Getting the disty recurved is a cool thing to do if you want to get the disty dialed in the way you want it. It does help to get better milage and the power into the right spot.

[Freightrain]

Not sure the money spent on a MSD dizzy will be worth the additional adjustments you have.

Since you have the Pertronic already, you are steps ahead of the stock stuff(even though I run points in about everything I have).

You can "recurve" your own dizzy to a point. Find a spring kit from one of the manufacturers and do it yourself. Pull the plate back out and try different springs. You can also get an adjustable vacuum diaphram(if you use vacuum).

Lots of little things you can do with alot less money.

[Lee]

Hi,

I just completed re-curving the dissy in my 70 F250 390. I ordered a Mr Gasket spring kit from the local parts house. It has 2 small springs in it and was just a few bucks.

There's not much to it really. You will need a timing light with the delay knob on it and a tach.

My stock dissy had a medium strength spring and a heavy spring. The reluctor was set on the 18L tab which means I had a total of 36* mechanical advance + 10* initial. With the stock springs the total timing did not completely come in till around 5200 rpm. This is to late.

After playing with spring combinations I ended up using one of the Mr Gasket light springs and the medium original spring. I also swapped the reluctor from the 18L position to the 13L position. I now have 10* initial and 26* mechanical advance for 36* total all in by 3000rpm. This does not include Vac advance.

At first I used both of the light Mr Gasket springs and this gave me all of the advance in by 2200rpm. With this I was getting "labor knock" or pinging. 2200rpm was just too soon.

The way I checked my curve was to have my wife push the gas and set the rpm using the tach while I operated the timing light. I checked it every 500rpm from idle to 3000rpm(in my case).

Hope this helps,
Lee

[69F100]

hey thanks fer the info guys!

[heep70]

Hi,

I just completed re-curving the dissy in my 70 F250 390. I ordered a Mr Gasket spring kit from the local parts house. It has 2 small springs in it and was just a few bucks.

There's not much to it really. You will need a timing light with the delay knob on it and a tach.

My stock dissy had a medium strength spring and a heavy spring. The reluctor was set on the 18L tab which means I had a total of 36* mechanical advance + 10* initial. With the stock springs the total timing did not completely come in till around 5200 rpm. This is to late.

After playing with spring combinations I ended up using one of the Mr Gasket light springs and the medium original spring. I also swapped the reluctor from the 18L position to the 13L position. I now have 10* initial and 26* mechanical advance for 36* total all in by 3000rpm. This does not include Vac advance.

At first I used both of the light Mr Gasket springs and this gave me all of the advance in by 2200rpm. With this I was getting "labor knock" or pinging. 2200rpm was just too soon.

The way I checked my curve was to have my wife push the gas and set the rpm using the tach while I operated the timing light. I checked it every 500rpm from idle to 3000rpm(in my case).

Hope this helps,
Lee

Hi Lee, Welcome to the Forum. Are you the same Lee that works for the FAA? Or maybe it is a flight center that has something to do with the FAA. Anywho, Great peice of info you whipped out there. I will have to give mine a try. I usually have a disty shop do it. Save a few dollors. Thanks Lee.

[68F250]

HI LEE!!

This is Barry, a.k.a. "BB" from FTE.

Good to hear from you! Glad you found us and look forward to having you around here!

Great info on recurving the dizzy!

Take care and see 'ya around!

Barry

[Lee]

Thanks for the "welcome aboard" fellas.

I have been out of touch with the internet lately.

Greg, Yup it's me the FAA, glow in the dark RADAR tech!

Take care,
Lee

[heep70]

OK. Stick around this time.