1)You have a six-pack hood. Great at 60 mph. Helps nothing at zero mph, under heat soaked conditions ,unless its sealed to the airhorn.
2)"The carb isnt leaking". I never suggested it was. I was asking about the boosters. I should have asked,is the intake floor wet?
3")and doesn't matter how much fuel I pump into the motor".Thats my point.It may be flooded.
4) "and it's firing when I turn the motor over" This goes back to flooding.
5) intakes are always hot. Cast-iron more so than aluminum
Heres the thing; Every engine needs,compression,a correctly timed ignition and a combustible air/fuel charge. You have the first two. That leaves the third. So since your air fuel charge is NOT combustible, its either too lean or its too rich. Since you say your "acc pumps work", and (it)"doesn't matter how much fuel I pump into the motor,that seems to indicate theres an over-abundance of fuel.........And thats called flooded.
So go figure out how the fuel is getting into the intake, while not commanded to.
Here are some possibilities
1)fuel percolation............Yes the intake is hot. It runs nearly the same temp as the water in the rad.Aluminum air gap types may run a tad cooler. At higher rpms with the fuel-air charge flowing through them, the temp may drop quite a few more degrees,but guess where the heat is going. And when the engine is shut down, the heat comes up, and cooks everything.
Now, I read that you have a wooden heat insulator spacer under the carb. Thats great.It works well on a running engine, and will delay shut-down cooking for a bit. Percolation happens when the fuel gets too hot and starts to boil . Some of the vapors exit the bowls through the vent stacks.Other vapors move up the fuel wells in the carb and into the venturies The vapors may push liquid fuel ahead of it, and/or with it. When it gets out of the bowl, the vapor parts rise into the air filter housing, while the liquid part dribbles down into the hot intake. In the hot intake it evaporates, and rises up past the T-blades, and joins the vapors trapped in the air filter housing.If percolation is severe, a lot of vapors will end up the air filter housing and some in the intake as liquid.It may run down through an open intake valve and end up in the chamber. And it may puddle on the port floor in front of the intake valve.In a short time it will all flash to a vapor.It will be at a higher pressure than atmospheric,so will attempt to move towards any lower pressure area, namely out of the engine. So it fills the intake manifold and moves through open intake valves, into chambers and perhaps into the headers. It goes where-ever it can.Eventually it all escapes into the atmosphere.
If you attempt to start the engine during the early phase of percolation,the hot engine behaves as flooded. A hot engines like less fuel,not more, so,its just too rich. The plugs may get wet, and short the spark to ground.Since the fuel in the bowls is more or less gone, and the fuel wells are dry, at least they are not compounding the issue.That is until the electric fuel pump fills them back up. By this point you may be frustrated and mistaking the flooded condition for lack of fuel,you may stab the throttle and inadvertently compound the issue.Or you open the blades a bit, and the acc. pump delivers its load.Remember the air filter house is still full of vapors as well.If you dont have an electric pump, then you have to crank the engine long enough to refill the bowls. More frustration.And perhaps more stabbing, leading to "doesn't matter how much fuel I pump into the motor"
Eventually, with the fuel all evaporated and dissipated, and the bowls refilled, the engine springs to life.
2) fuel blend.................They blend fuels differently for the seasons. Winter fuel is blended to help cold starting. Summer fuel is blended to help combat evaporation.During the change of seasons we sometimes get caught with winter fuel on a hot day.
3)Carb design...............Some carb designs have been known to internally leak their fuel into the intake.I dont know about the 1050.
Solutions; So how does one combat percolation.
Dont ever under any circumstances,shut the engine off hot! Ever!.......... lol,kidding!
#1) is with the blend. Make sure you have summer fuel.
#2) Heat creation; The first line of defense is to not get the underhood air so hot in the first place.This starts with the ignition timing. If you fail to start the fire early enough, the charge continues to burn following the piston all the the way to BDC and beyond. Then it dumps that heat into the cooling system, through the cylinder walls and water jackets. And some gets into the headerpipe.If it burns in the pipe, it will make a lot of underhood heat. So not only do you not get the full use of that energy,it actually goes into places you dont want it to.So get the timing right first.
#3) Heat management. We have to get the temps down.The fuel temp, the air temp, and the engine temp if need be.
Starting with the fuel temp.Lets see where the heat originates. If you have a mechanical pump, which is screwed to the hot engine,its passing its heat along, into the fuel as it passes through it, and into the steel line,following. The steel line passes behind the hot rad and into the hot-air-disharge. Then, usually the steel line passes over the hot water passage close to the stat-house and over the hot intake on its way to the carb. Do you see a pattern here? By the time the fuel gets into the bowl, its ready to flash. Now consider that up to this time the fuel has been under pressure. But as soon as it gets past the needle/seat it losses all pressure.When this happens,( hot fuel going from a pressurized state to atmospheric pressure), it likes to boil almost irregardless of the temp of its new environment. So the fuel may boil instantly as it drops into the bowl.The extent of this boil is somewhat dependent on the temp of its new environment. So on a cold winters day it may not flash at all. But in summer and dropping into a hot carb, look out!
So, whats a guy to do?
Well, follow the steps; starting with the timing.
Then get that fuel line temp down.The next is to get the carb temp down.After that, if it still percolates, its time to figure out how to get rid of some of that underhood hotness.
Getting the fuel temp down, is be shielding and heat-sinking, and maybe a thermal break.
Getting the carb temp down, youve already got a handle on.
Getting rid of underhood heat at shut-down is hard.When the heat comes up theres no where for it to go.
I have a 68 Barracuda. It has those little hood inserts. I took them off, and cut a series of slots in the channels were they mount, They are as wide as I could make them(maybe 1.25 inches) and about 3 to 4 inches long each, and as many as I could fit between the under hood supports. Then I made some spacers and installed them on the studs of the "louvers", and reinstalled them.In this way the louvers sit about 7/16" above the hood-line. Most people dont notice it, nor the vents. I know the Duster has a more or less flat hood, so this is out for you. But I think with the 6-pac hood, you could dream something up,if you had to. Before I cut the vents, I raised the rear of the hood about 1/4 inch, and removed the cowl seal. This was to prove my problem was heat-soak and percolation.It solved the problem right off, but noxious fumes entering the cabin at speed, limit this to open-window testing only.
Another possible solution, is wrapped or coated headers.
Okay thats all I got for now....
