DIZZY SHAFT PLAY
#1
12-04-2018, 12:02 PM
#2
12-04-2018, 12:16 PM
#3
12-04-2018, 12:20 PM
#4
12-04-2018, 02:26 PM
My dizzy was loose enough and my cam worn enough that it was hitting against the side of my Pertronix unit and broke it. I now have a new Pertronix billet distributer with the Igniter III set-up waiting to be installed.
I don't know how hard it is to rebuild...although there is a racing shop that has full machine services that I'm going to send my original to for rebuild in the event that I show the car and want to reinstall original points set-up.
I don't know how hard it is to rebuild...although there is a racing shop that has full machine services that I'm going to send my original to for rebuild in the event that I show the car and want to reinstall original points set-up.
#5
12-04-2018, 04:00 PM
Next, Ford shop manual (in bold letters no less) wants a new distributor gear installed whenever shaft is replaced (and the reverse is also true as well) So that means drilling holes, or new holes, which then must be located accurately in order that the overall distributor and end play dimensions &c are within spec, +/- 0.006 in. In other words, it's much easier to start shopping for an NOS or Service Replacement. But again, if you're picky you will notice an improvement in how it runs with a fresh tight distributor.
#6
12-05-2018, 01:54 PM
The dist. shaft in my 68 360 had some slop, enough that it I couldn't get dwell within spec. I ended up putting on electronic ignition (Accel) which was a good upgrade in my opinion.
I also took the dist. apart as far as it would go without removing the shaft, which requires you to press gears on and off. Don't have the tools for that. I just cleaned all the removable parts well and used a little white lith on all rub spots when putting back together. Manual says to mark position on weights and springs when coming apart; not sure why on springs, but I did so for weights. Since I couldn't take the shaft out (and it was clearly gummed up somewhere because it would bind some when spinning by hand), I plugged the weep hole in the body and sprayed a bunch of PB blaster in the bottom and worked it down into the bushings (I think?) by spinning it a lot. Let it sit over night like this, then drained and wiped it down as best I could. Lot's of crap came up and out and the unit spun much better/freely by the time soaking was complete. Then I filled it with some oil and again spun the shaft to work it down in and let sit over night. Drained and flipped to sit and and let remaining oil come down and out, wiped it down good, then proceeded to put back together. Happy with final result, seems to have made an improvement in function despite not pulling fully apart. Note, I only took this approach since the manual says to oil the bushings before re-installing the shaft and I figured I could get oil to them by letting it perc down overnight. It's been about 50 miles since i put it back together. The only tricky part was getting the retainer off the cam lobe part so I could pull it off the shaft. After much fiddling, I was finally able to get it off with needle nose pliers and a screwdriver.
I also took the dist. apart as far as it would go without removing the shaft, which requires you to press gears on and off. Don't have the tools for that. I just cleaned all the removable parts well and used a little white lith on all rub spots when putting back together. Manual says to mark position on weights and springs when coming apart; not sure why on springs, but I did so for weights. Since I couldn't take the shaft out (and it was clearly gummed up somewhere because it would bind some when spinning by hand), I plugged the weep hole in the body and sprayed a bunch of PB blaster in the bottom and worked it down into the bushings (I think?) by spinning it a lot. Let it sit over night like this, then drained and wiped it down as best I could. Lot's of crap came up and out and the unit spun much better/freely by the time soaking was complete. Then I filled it with some oil and again spun the shaft to work it down in and let sit over night. Drained and flipped to sit and and let remaining oil come down and out, wiped it down good, then proceeded to put back together. Happy with final result, seems to have made an improvement in function despite not pulling fully apart. Note, I only took this approach since the manual says to oil the bushings before re-installing the shaft and I figured I could get oil to them by letting it perc down overnight. It's been about 50 miles since i put it back together. The only tricky part was getting the retainer off the cam lobe part so I could pull it off the shaft. After much fiddling, I was finally able to get it off with needle nose pliers and a screwdriver.
#7
12-05-2018, 08:19 PM
My dizzy was loose enough and my cam worn enough that it was hitting against the side of my Pertronix unit and broke it. I now have a new Pertronix billet distributer with the Igniter III set-up waiting to be installed.
I don't know how hard it is to rebuild...although there is a racing shop that has full machine services that I'm going to send my original to for rebuild in the event that I show the car and want to reinstall original points set-up.
I don't know how hard it is to rebuild...although there is a racing shop that has full machine services that I'm going to send my original to for rebuild in the event that I show the car and want to reinstall original points set-up.
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#8
12-06-2018, 06:18 AM
Fleet Mechanic
#9
12-06-2018, 11:13 AM
I can't do this right now but I would like to know how you check it with a timing light. I have no clue since you can't access the dizzy shaft when the engine is running. How do you check it Alex?
#10
12-06-2018, 11:54 AM
You can see slop or stretch in the timing chain especially, and other distributor issues, by running the engine up through a few thousand RPM and observe whether the timing marks "scatter", what you want to see is that they advance and retard smoothly up and down the RPMs back to initial timing without sticking, and they should stay sharp and focused throughout.
Another way to infer distributor shaft/bush wear is with a dwell meter, as mentioned it will not be able to meet spec, or hold it. This is really the best way to set ignition timing accurately, once points have been in service and have some wear. The feeler gauge just gets it close enough to start.
An ignition oscilloscope will show a worn distributor very clearly, the firing pattern including dwell of all the cylinders can be observed singly on the screen or, all cylinders superimposed on top of each other, with excessive sideplay the patterns won't overlap cleanly because the dwell is inconsistent and the whole pattern will wobble. On my old beast could hear it too, the scope patterns coincided with a lope in the idle. Near as I can figure and it stands to reason, like other similar bearings the bushing tends to wear in an egg shape pattern.
Another way to infer distributor shaft/bush wear is with a dwell meter, as mentioned it will not be able to meet spec, or hold it. This is really the best way to set ignition timing accurately, once points have been in service and have some wear. The feeler gauge just gets it close enough to start.
An ignition oscilloscope will show a worn distributor very clearly, the firing pattern including dwell of all the cylinders can be observed singly on the screen or, all cylinders superimposed on top of each other, with excessive sideplay the patterns won't overlap cleanly because the dwell is inconsistent and the whole pattern will wobble. On my old beast could hear it too, the scope patterns coincided with a lope in the idle. Near as I can figure and it stands to reason, like other similar bearings the bushing tends to wear in an egg shape pattern.
#11
12-06-2018, 03:46 PM
Fleet Mechanic
#13
12-07-2018, 09:49 PM
#14
12-10-2018, 05:11 AM
My hand is up. I bought my first one because the Mercury Comet I had bought had a dual point dist in that Boss 302. I couldn't get the points set right with just a feeler gauge.
#15
12-11-2018, 08:04 AM
You can see slop or stretch in the timing chain especially, and other distributor issues, by running the engine up through a few thousand RPM and observe whether the timing marks "scatter", what you want to see is that they advance and retard smoothly up and down the RPMs back to initial timing without sticking, and they should stay sharp and focused throughout.