I have a d100 truck with a slant out of a car ( judging by the center sump oil pan. Is there a difference between the car vacuum advance pod and the one that would be correct for the heavier truck. What is the relationship between advance curve and vehicle weight?

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Decrepit 1976 d100 undergoing a rolling restoration.

You will have to check the differences in the guts between your old distributor and the new one. Typically trucks got a moderate slot governor (less initial) with heavier springs and a low advance vacc. pod.
The combination is to fight pinging by slowing down the advance and keeping the total low across the board (think underpowered brick with lots of throttle open to try to get it to move),even in the 70's trucks were getting a 13R governor for 26 degrees of mech advance where the cars had gotten a boost of low end torque by using the 9R governor and lots of initial....

-D.Idiot

Yes it's definitely different. You will need stronger springs on the mechanical advance weights. I fought this on a truck that I thought I could just drop in a car engine. Spark-knocked across the board. Ended up burning a hole in one piston and not one ring was all in one piece.

Adjust, adjust, adjust. It won't be right anywhere. Advance the timing to start it and then retard it to drive it. Still pings going up hills. Just don't work.

Danny

Just the info I needed to get started on this project!

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Decrepit 1976 d100 undergoing a rolling restoration.

Yikes! I have a 74 Duster engine in my Town Wagon. I haven't done any extensive testing yet (no big hills or long runs) but it sounds like I should expect some pinging. It has been running great around town though.

I'm not really up on changing the springs in the distributor but I'm ready to learn. Is it just trial and error or can I buy the right springs and stick em in?

Thanks

Derek

Yes, contact "Bigslant6fan" for the spring kit. It is not hard to do other than the tear down required on MOPAR distributors. Make a log before and after to track results.

Go to the Recurve section under Engine FAQ.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks for the advice. Just to clarify, the re-curve article talks about lighter springs but above it was suggested heavier springs were needed. Which is right?

Thanks

Derek

The springs needed are going to be dictated by the weight of the vehicle and useage. The heavier the vehicle, the longer your going to want to hold the timing out. There isn't any one size fits all timing curve out there.

What are you driving, what is your engine setup, and what are you doing with it?

In effect, my timing curve is all in once the car starts. Not very useful on the street.

CJ

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Part of Tyrde-Browne Racing

CJ - the vehicle is a D100 Town Wagon (about as heavy as they come!). the engine is from a 74 Duster with the original Chrysler Distributer (Duster) and HEI conversion. Super 6 set up. Used for everyday driving.

Thanks

It's a brick. If it doesn't ping now, you're in good shape, but there may be more in there, the 1973-1974 A-body slant six was curved for the initial to be TDC from the get go...on the lighter car this distributor could almost be dialed in at 5-8 BTDC initial if it didn't ping with some good results assuming that the stock holley 1945 carb had it's main jet changed from a weezy #58 to something more like a #60-#61.

Timing and carburation have kind of a frenetic relationship between each other:

If you change one, you may need to do a bit of adjustment to the other.
I've seen some guys that have mistaken carb problems that were actually timing/advance problems...and the other way around.

One thing for sure: if it's light, the advance can go quicker, so lighter springs in your distributor, if it's heavy or towing it will need a slower advance since the vehicle can't accelerate that fast.

-D.Idiot

Nice rig!

Listen to Professor DI. He knows his way around a distributor, and has pulled many a rabbit out of his hat dialing a carburetor in.

With a little work, you ought to be in the right place!

CJ

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Part of Tyrde-Browne Racing