Project #002 Phases 1, 2, & 3

Phase 1 - Exhaust Leaks
Exhaust leaks are eliminated. Replaced both donuts on the manifolds and installed one of the Remflex gaskets on the passenger side manifold. This was a piece of cake until I got to the top rear bolt on the manifold. I am very grateful this is not a modern vehicle, otherwise the bolt would almost certainly have broken off. In the end it came out and it all went back together just fine.

The other gasket will need to be replaced but it is fine for now.

Phase 2 - Reliable Ignition System
The ignition system is not quite as reliable as I would like but I think it is good enough for the initial tuning I will be doing. I have a nice set of Accel spiral core wires for the truck. If these wires are treated right they should last for nearly the life of the rig so I want to do a nice job routing them. When I bought the wires I also bought a plug wire stripper and crimper tool. This turned out to be a total wast of money. First, the plug wires came with a set of vice mounted crimpers. Second, the wire strippers suck. It is important that I get nice clean stripped ends to get a clean wire install. So I ordered another tool that I think will be just the thing. Unfortunately it is a special order item and hasn't arrived yet. This puts the whole ignition system upgrade on hold. I can't install the new ignition box and coil until I install the new plug wires and I can't install them until I get the wire stripper. I'm using this time to get the wire routing sorted. I will be ordering some wire routing accessories this week. They'll probably get here before the wire stripper. The present ignition system will be good enough for our purposes we just won't know how lean we can go in a few driving circumstances.

Phase 3 - Carburetor Tuning
This is the one I really wanted to write about. The carburetor is a Carter AFB competition series. This will be the routine we follow:

1. Tune primary barrels at low manifold vacuum (high load) and WOT (Wide Open Throttle). Lock out the secondaries so we are just measuring the primaries. This will establish the jet size. There is no point in adjusting the metering rods if the primary jets won't flow enough fuel. I will be using the metering rods with the narrowest enrichment diameter (They will flow the most fuel).
   
2. Test A/F ratio with primaries at WOT over varying load conditions. I will want to see when the metering rods are moving and how the air/fuel ratio looks.
   
3. Tune/observe primary part throttle A/F ratio over various manifold vacuum readings. I am not sure how well I will be able to tune this because of the metering rods I have. This is where the metering rod tuning will commence. There are three tuning areas. The metering rod's enrichment diameter, the metering rod's economy diameter, and the spring that determines when the metering rods move (i.e. when the two metering rod diameters are inserted into the jet). This is where I will be making adjustments in these three areas.
4. Tune idle and off idle circuits. This carb does not permit easy adjustment of the mixture of these circuits. The idle adjustment screws only adjust idle mixture VOLUME. It looks like the fuel restriction for the idle circuits is hard to get to but I may be able to do the adjusting I need by varying the size of the idle air bleed. I will have to check in to this before I start drilling. These are serious modifications.
5. Now with these circuits in order I will unlock the secondaries and test the overall fuel mixture at WOT. Since the other circuits should be in order any variance from the ideal (or at least the best achieved at the other load conditions) will be corrected by changes to the secondary jets.

That sounds pretty straight forward. We'll see what the results are.

Builder