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Discussion Starter #1
I am officially confused. The books I;ve seen say to hook up the test lamp (hot side of ignition coil and ground). I presume the lamp should be illuminated with crank pointer on F mark. Then turn counterclockwise until the lamp goes out (points closed), then clockwise until it turn back on (ie points are now open). True?

Where I am confused is the leading/lagging edge of the disributor cam lobe. I am assuming that at F mark, I should be on the leading edge of the cam lobe going 'uphill' towards turning the lamp off -- correct? What this then means is that when I have everything buttoned down, as I turn the crank and approach the F mark, the light should turn ON (I am turning the crank clockwise from the front nut) right at the F mark -- correct? That means that the points OPENED on the leading edge of the dist cam lobe right at F?
YEs/no? Part of the trouble is that the collar that spins on the dist was loosened and now I am trying to get it centered again
Thanks in advance
 

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71 Berlina 74 GTV 17 Giulia Q4
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BYes No need though to turn the crank though. You should be turning the distributor anti clockwise and nail it down when the points open. The easy way is with the ignition on turn the distributor and stop when you see the points spark as they open. Although with a marelli it might be hard to see the spark. (Rotor pointing to #1 and cam lobes on 1 pointing out. )
 

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Discussion Starter #3
Sorry about my denseness

Assuming the distributor timing is correct, does the light go from OFF to ON when I hit the F mark, or,

Does the light go from ON to OFF when I hit the F mark

when I turn the crank clockwise from the front?

I believe it should go from OFF to ON as the crank is rotated to the F mark when the distributor is properly timed?

thanks, bob
 

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71 Berlina 74 GTV 17 Giulia Q4
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Before I answer that what happens if the light comes on before or after the f mark hits the pointer? The timing is off so you change the distributor and try it again, and again, and again. Why not leave the crank still and move the distributor once?
 

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Discussion Starter #5
I'm just trying to get it close to try to revive the car.. If it comes on 2 or 4 degrees before or after F mark I don't care since I will time it properly once I can get it to actually run....
 

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Light goes on when points are open.....??
Darn it, now I'm confused! One problem is that in post #1 you wrote: "hook up the test lamp (hot side of ignition coil and ground)." A light hooked up that way will always be on, as long as the ignition is switched on.

You want to connect the test light between the coil "-" and ground. A light hooked up that way will be on when the points are open, and off when the points close (and ground the "-" side of the coil).

So yes, you turn the distributor CCW until the light goes on (e.g., when the points open).
 

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Discussion Starter #8 (Edited)
Thanks All,

I am not communicating well it seems.

I will figure it out and post the answer to the question

"when turning the crank clockwise, with mechanical timing (cam-crank) set correctly, and distributor timing set correctly, and a test lamp connected between breaker point 12V source and ground, when approaching the F mark on the crank pulley( going clockwise as the engine would normally turn) , does the test lamp transition from ON to OFF or from OFF to ON.?"


http://www.alfabb.com/bb/forums/gt-1963-1977/20257-difficult-cranking-my-1974-gtv-2.html
 

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I'll have a shot...

The way to think about the test light and the points is
1) you want the test light to tell you when the points open and close (yes, obvious)
2) the points are in the middle of the "ground line" from the coil -ve to ground. Just think about the test light as being across the points. When the points are closed, it is a short circuit, and the light is off (there can be no voltage across the short circuit). When the points are open, the light is on, 12V being across the points.
3) contrary to what would seem intuitive, the coil fires the plug when the points are opened, not when they're closed. In other words, if things are being rotated in the normal direction, the light will turn on when the plugs are being fired.
4) normally the static timing though is done with the crank at the F mark, and leaving the crank still, along with the distributor rotor. So the body of the distributor is being turned with respect to the distributor rotor.
5) Because the body is being turned, it's backwards. Turning body CCW is the same relative motion as if the motor was turning "forward" in normal running direction. Look at the rotor by itself, compared to the body, while you turn the body CCW, and it's clear that the rotor is turning "forward" ie CW.
6) So you normally set the motor to F, keep it still, then turn the distributor body all the way CW, then get the light in place. This starting point is before the point where the plug fires, so the test light will start being OFF (points closed). Slowly turn the body CCW until the light goes ON. This is your static timing spot, being the switching spot between points closed then points opening (when things are turning "forward"). If you had to loosen the clamping plate to find the place where the light comes on, then you can now center the slot and tighten it.

Hopefully I didn't get myself mixed up while writing it..... :whistling:

/Neil
 

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2) the points are in the middle of the "ground line" from the coil -ve to ground. Just think about the test light as being across the points. When the points are closed, it is a short circuit, and the light is off (there can be no voltage across the short circuit). When the points are open, the light is on, 12V being across the points.
3) contrary to what would seem intuitive, the coil fires the plug when the points are opened, not when they're closed.
Yes! A well written explanation.

goats said:
...and a test lamp connected between breaker point 12V source and ground...
When your manual says "breaker point source" it means the "-" terminal on the coil - the place on the coil that is connected to the points. That manual would have been a lot clearer if it had simply said: "connect the test lamp between ground and the "-" terminal on the coil".
 

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Discussion Starter #11
Thanks all. Neil your explanation is great ! I completely understand the circuit part of this ; no problem. Where I am hung up is the actual mechanical linkage that is supposed to

a. "Instantly" open the points (turn off the bulb) as the crankshaft, rotating clockwise, passes the F mark

b. The inherent mechanical hysteresis in the entire assembly. The dist rotor when it is turning via the crank should be turning clockwise, yes? Clockwise movement of everything to set the timing should reduce the 'slop' in the system I would think. I suppose that turning the dist body CCW until the light goes out has no real effect on rotor hysteresis/etc so that is what I will try.

Thanks again all I will update as this unfolds. I hope to be getting closer to having this car running.
 

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Where I am hung up is the actual mechanical linkage that is supposed to

a. "Instantly" open the points (turn off the bulb) as the crankshaft, rotating clockwise, passes the F mark
Ah - confusion about how the points themselves work ?
If it's that, I don't have any pics handy, but basically the wiper on the cam pushes the points apart as it peaks - the wiper is on the outboard point "plate" (toward the outside of the distributor) so the wiper pushes this side of the points away (outboard) from the other one. If this is a Marelli, as gigem mentioned, the points are hard to see, being under a big fat rotor plate and advance mechanism... How worn the points and the wiper are will change the "dwell" angle (how much angle of rotation the points are open vs closed) that used to be important to measure but doesn't seem to be considered much anymore...

About the second point b) yes there is some slop between the oil pump shaft notch, and the dog drive that fits into it on the bottom of the distributor, and between the dog drive and the pin that holds it to the distributor shaft. It is a source of timing jitter when running, but it wouldn't make much of a difference for the static timing that we're discussing, at least IMHO.

HTH...
/Neil
 

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71 Berlina 74 GTV 17 Giulia Q4
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If all you want to do is start it just eyeball the rotor ( turn the distributor ) to where it is just about to line up with the position of the plug wire in the cap that the motor is about to fire on. Works everytime.
 

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Where I am hung up is the actual mechanical linkage that is supposed to a. "Instantly" open the points (turn off the bulb) as the crankshaft, rotating clockwise, passes the F mark
The four lobed cam in the distributor works exactly like the one lobed cam that drives each intake and exhaust valve. You understand how those work, right? So pretend the valve was wired to your coil's "-" and the valve seat provided a path to ground (ignore that the valve guide would create a short). Once the valve begins to open, it would break that electrical connection. Does that mean that the valve is opening "instantly"? Well, no. But, at some point it opens enough to interrupt the flow of current.
 

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Discussion Starter #15
Thanks Jay. I think mine probably has 4 lobes but haven't counted em!

YEs I get it. Thanks everyone for the help. I will have it set tonight without a doubt. Have a new battery coming in as well so hopefully I am closing in

One other question gurus -- there are 2 valve cover nuts with 'fibre' washers. Which positions do they occupy vs the other ones without the fibre washers?

thank you all
 

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The aluminum washers go at the back to get a good squash of the half moon rubber plugs under the cam cover. The four fiber washers go in front and the middle.
 

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Discussion Starter #18
Ok I can report a happy conclusion to this saga. Tonight I went back and with the rotor pointing towards the front (#1) I removed the o-ring so I could easily pull the distributor/replace it as I worked the collar to get a) the light to be off with the dist rotated all the way clockwise and light on when rotated counterclockwise with crank in F position.

I then worked the collar to make the light turn ON when rotating dist counterclockwise roughly in the middle of the arc. Removed the dist, replaced the oring, replaced dist, turned fully clockwise (light was OFF) and rotated counterclockwise until light came ON (in the middle of the arc). Tightened it down.

Then started manually rotating the crank 4 blinks of the light later when it goes on I am right at the F mark.

SO -- Test lamp run in parallel with the points turns from OFF to ON when the pointer hits the F mark.

Installed the plug wires, etc and cranked the car. It fired and ran rough for about 5 seconds. That was all I needed tonight. Since I am setting up spica from scratch, etc I think I'll need some more time to get this going.

Thanks everyone. Will keep everyone posted as this comes along.
 

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Discussion Starter #20
OK some happy news and some really disappointing news

Happy -- after I set the static timing, I pulled the plugs out, cranked the motor over a bunch to get some oil pressure, then put everything back together and -- beautiful, car started, idled, and ran really well (theres no accel cable and I dont want to do much before I can seat the rings. so great news on that front

Bad news -- I had a persistent oil leak dripping from lower pan. Tried goosing up the bolts, no good. So I pulled the pan down tonight to see what was going on. There is a crack in the bolt boss on the lower pan, it goes all the way through the pan down to the bolt hole face. Its about 0.015 wide and all the way from the sealing surface to the other side bolt shoulder. (the crack)

So I think I have 2 options. One, source another lower pan without any cracks but in good shape. Anyone have one to spare? Second, apply some permatex in the bolt hole; set the bolt, and hope it seals it up. I guess theres a third- get it welded up (very light Aluminum there though, and would have to be surface ground I guess to get it flat.

Next a few questions
1. What is the order for re-torquing those lower pan bolts (start from middle and work outward?
2. What is the recommended torque value?
3. Sealant or not on the gasket? Types? application guidelines?

many thanks - looking for help for sure!
 

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