I just came in from a cruise with my freshly recurved D-150 truck. I was skeptical of it working properly and pinging. Well, I can tell you it makes a whopper of a difference (it felt like I had 20+ more horses). The truck is considered mildy modified, so it could work for you if you have been reluctant. My stock distributor had a 9R governor plate and a 11R vacuum advance cannister. I took out a really beefy looking advance spring and put in one from the P2932675 distributor recurve kit (only has two identical springs in it). Put the thing back in, fired it up and set my initial timing to 12*BTDC. WOW what a difference!. I will drive with it like this for a few days and see if I need to change the initial advance, but for now it sure is FUN. I only noticed it pinging under fairly hard acceleration in third gear @ 35MPH (I admit it, I was bogging it a little).

bwhitejr

_________________
'72 Duster (Performance 360)
'83 Ramcharger (Performance 318)
'80 TrailDuster (360)
'80 D-150 Truck (See Below)
CompCams 252S, Holley 390cfm, Offy manifold
Ported, Polished and Gasket Matched
P4286813 Springs,0.040 Overbore,
0.090 Shaved Head

Things you want to do is keep track of your changes or you might not know what is doing good or bad for your build (power might be good, but your mileage may go to pot)...need a place to go from and what happened (got more mileage, got more power, plug are black and it pings...)

When a spring change occurs, I run an underhood tach and dial back timing light, with the vacc. advance disconnected and note the advance in degrees on a note pad over the course of a selected set of rpms (800,1000,1200,1400...2700), this way I can see how the 'curve works' (where the rpm vs. timing is good for shifting in traffic, on the highway).
I also run the rpms up to a certain point and connect the vacc. advance to a hand pump and note where and how much timing change comes in at certain vacc. points ( this might help figure out pinging in load/lug situations, can also help figure out where your carb tuning might need to be finnesed)...don't forget to check them plugs too...

Fuel and Timing are related in tuning, when you change the timing you may have to adjust the carb a bit, and vice versa...

Keep going!


-D.Idiot

Thanks. I guess I was a little too euphoric.

I did all of the above before I started the changeover. I sure hope the gas mileage doesn't get worse. The plugs were sooty before the change and it smelled a little rich most of the time. I will hook up the dial-back, the vacuum gauge and the Mighty-Vac tomorrow. I just expected it be a dissaster and quit for the day with a mild success. Here is to continued success tomorrow

bwhitejr

_________________
'72 Duster (Performance 360)
'83 Ramcharger (Performance 318)
'80 TrailDuster (360)
'80 D-150 Truck (See Below)
CompCams 252S, Holley 390cfm, Offy manifold
Ported, Polished and Gasket Matched
P4286813 Springs,0.040 Overbore,
0.090 Shaved Head

In case you missed it, Reed started a topic 'distributor questions' which has a link to some very lengthy information I've collected on distributor recurves.

You have been asking good questions and it sounds like your doing well.

When I have more time, I'll want to get more details about what you've done and some mileage results once you've tested a little more.

_________________
1980 Aspen 225 super six

Thanks Slant6Ram. I read your article when it was first posted( about a month ago). I used it to get a handle on what I was up against. I even re-read it this moring before I started. It must have bolstered my courage, because I went out and braved the Ping Monster.

Thanks for all the insight!

bwhitejr

_________________
'72 Duster (Performance 360)
'83 Ramcharger (Performance 318)
'80 TrailDuster (360)
'80 D-150 Truck (See Below)
CompCams 252S, Holley 390cfm, Offy manifold
Ported, Polished and Gasket Matched
P4286813 Springs,0.040 Overbore,
0.090 Shaved Head

Yeah, slant six ram's article is a very good one. I am getting ready to swap my van from lean burn to HEI ignition and will be recurving the distributor as well.

Let me know how your recurve works out. I will be starting with a very similar distributor and my van weighs as much (if not more) than your truck.