autotlite IAZ 4003A dissie ... from a 241 hemi .. working on a curve for it.. got the mechanical advance dialed in at 24* by welding up the t-bar slots. the va needs a a number "8"stamped arm (linkage ) mine has a 11.5 stamped va arm .. is there any other way to adjust the VA to get it down to 8* .. maybe with a shorter , thicker ,lighter ,longer Springs or with washers more or less? . another gentleman had a article about placing a tube over the linkage arm to limit it's travel. here is a pic........ of the insides my dist with the stock ma springs going to replace one of the springs with a lighter one.. you guys have any suggestions ? Thanks ! that is where I am at now .. been looking for the #8 arm but no luck .
here is a pic of the vac adv can with 11.5 hg in it. from what I gathered from looking at several different va cans is the heigher the number the longer the linkage arm. also pic of the area where mopar back in 54 hotrodding slipped a small pice of tubing over the linkage arm to limit amount of travel thus limiting the amount a degrees the va will pull out of dist.
in this pic .. the va arm linkage red arrow where a pipe tubing is inserted over linkage to limit travel to curve va . does this make any sense to anybody . obviously that would limit the travel .. would that lower the number ? 11.5 to 8 ?
A couple thoughts. The numbers inside the unit " Z26R" show that the distributor has 26 degrees of advance and is a right hand unit. A good clean and lube will more than likely restore the factory curve as needed, these get gummed up and restrict the advance action. The springs are adjustable by bending the mounting tabs and very seldom require replacement. The spring tension changes the advance rate to a working curve of progressive advance.. To limit the vac advance just slip a piece of winshield wiper rubber hose inside the spring inside the diaphrahm. These cast iron units are some of the best distributors ever made and work very well with a little care.......
bubba Thanks for the info ! when I measured this oem dizzy t-bar slots they mesured .415 .. that equals aprox 11 dist degrees x 2 = 22. short of being 13* at .445 slots as the dist Z26R stampings . go figure . My goal is to achieve 24*ma + 8* IA and 16* Va for total 48* . this is for a 241 hemi . Bubba .. the rubber hose inside the va spring ...is that the same length of the spring or shorter accordingly ( different lengths for more or less in degrees) ? should I replace one of the two ma springs with a lighter one ? just concerned about bending the attaching point back and forth for adjustment and snapping it off. Thanks for your help . appreciate it ! john
Rubber hose would be less than spring length... I would not replace any of the springs. we bend these arms all the time , have never broken one.......they can be adjusted with the breaker in place....
Thanks Bubba ! The hemi distributor curve is finished . this should really wake this 241 hemi up some . just waiting now for the engine to be completed with the rebuild.
subscribed, very interesting topic as i will need it soon on a 241,, i think hot heads does a conversion like this,,,
update on the curved hemi dizzie >>>>>>>> I should have my rebuilt hemi in the car in another two weeks .. then we'll put some fire in the holes and see what we have. it's been 3 months since I last started the rebuild on my 241 hemi.. I should have the block back from the machine shop in a week and then I will reassemble it. stayed tuned. john
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