Need Dual Point Assistance

[67 GTX]

Using the right carb vacuum? Usually two at the carb base, one full, one ported, looking from the front, ported would be on the right side (Carter/Eddy). That's the one to use. Any chance of a vacuum leak?

Dragon Slayer is right, on things to check. Sore subject, but points gap/dwell, for that distributor, should be in the book. If it's not working with the right numbers, something is worn, not letting it act right. Basics, cam and following blocks. See any wear?

I believe my carb only have 2 possible openings. One is a bigger inlet, and that goes to PCV. The other one is the one I've always used to the vacuum advance. I have a vacuum gauge on that the other day, and confirmed it is carb vacuum. The vacuum increases with engine rpm.

Does anyone have a FSM showing the spec's for a dual point 67 440? Mine doesn't show it. Perhaps that could be the issue here?

All parts look fine. I checked for bushing wear, and it was within spec. When I pulled a vacuum on the distributor with the cap off, the points plate moved freely.

 

[Dragon Slayer]

Funny, The 67 parts manual shows the distributor as the HP 440 Manual trans Without CAP (without emission stuff), but FSM does not show it.

Use the Hemi distributor manual without CAP. It will be very close. Basically it is 12.5 deg BTDC Initial timing.

But you have to know what the mechanical is doing. It could be stuck, it could be giving too much advance. This distributor is 51years old, I doubt your the first one in it. Chances are parts are not original, therefor you could be getting too much mechanical advance, or if stuck none.

Compare the 67 hemi cap versus non cap numbers in your FSM and you see what I was talking about before. Your cars starts with 12.5 initial and the mechanical adds about 17 for a total of 29.5. The cap hemi starts at 0 initial and the mechanical adds 30 for a total of 30. The vacuum at cruise adds another 18-20 degrees of advance for about 48 to 50. Typically the 440 can take a few more degrees of advance then the hemi.

 

[miller]

Does anyone have a FSM showing the spec's for a dual point 67 440? Mine doesn't show it. Perhaps that could be the issue here?

Yes, that probably is part of the issue...application. Is there a #s tag on the distributor? I'll also ask, what carb?

Looked through my copy of the 67 FSM, electrical, specs. Problem...yes, shows two distributors, one Chrysler made single point, one Prestolite dual point. Just as Dragon Slayer says, the Prestolite is only under 426 Hemi specs.
If you have a distributor part #, you could look it up, for application/specs. Of course your dual point will work on a 440! But, need specs to make it right.

And, your dealing with older parts, older specs, like these (the same I remember from back in the day, lol).

Point gap (each) .014 - .019
Dwell (each) 27-32 degrees, (total) 37-42 degrees
Initial timing 12.5 degrees
Plug gap .035"

(Not that these won't work, just keep in mind, these #s are for the Hemi! They are also about the same for other BBs I've fooled with.)

 

[67 GTX]

Yes, that probably is part of the issue...application. Is there a #s tag on the distributor? I'll also ask, what carb?

Looked through my copy of the 67 FSM, electrical, specs. Problem...yes, shows two distributors, one Chrysler made single point, one Prestolite dual point. Just as Dragon Slayer says, the Prestolite is only under 426 Hemi specs.
If you have a distributor part #, you could look it up, for application/specs. Of course your dual point will work on a 440! But, need specs to make it right.

And, your dealing with older parts, older specs, like these (the same I remember from back in the day, lol).

Point gap (each) .014 - .019
Dwell (each) 27-32 degrees, (total) 37-42 degrees
Initial timing 12.5 degrees
Plug gap .035"

(Not that these won't work, just keep in mind, these #s are for the Hemi! They are also about the same for other BBs I've fooled with.)

The tag on the distributor reads: CHRYSLER 2642899 IBS 4006 Z 466
Carb: 4326s

I believe I did use the hemi specs when setting the distributor up

Since I used the dwell as the final setting, my point gap (each) is .010
That point gap gave me an individual dwell of 30 for each, and a total of 40.
Initial timing is set to 12.5 degrees
Plugs are gapped at .035"

 

[miller]

Since I used the dwell as the final setting, my point gap (each) is .010

Okay. I'm not up to this stuff, like Dragon Slayer, but honestly, .010" point gaps doesn't sound right. Unless the cam has some wear on it.

Couple dumb questions...standard or auto trans? Sometimes makes a difference on initial timing.
On the distributor, cap off, have you tried turning the rotor, to see if it moves freely during mechanical advance? It should move one direction only, given number of degrees, and when let go return to where it was.
On those mechanical advance parts, under the points plate, they need to be cleaned and lubed, usually once a year.

 

[67 GTX]

Okay. I'm not up to this stuff, like Dragon Slayer, but honestly, .010" point gaps doesn't sound right. Unless the cam has some wear on it.

Couple dumb questions...standard or auto trans? Sometimes makes a difference on initial timing.
On the distributor, cap off, have you tried turning the rotor, to see if it moves freely during mechanical advance? It should move one direction only, given number of degrees, and when let go return to where it was.
On those mechanical advance parts, under the points plate, they need to be cleaned and lubed, usually once a year.

I thought similar on the gap, but it was the only way to get the proper dwell. The cam didn't look bad, but of course it's hard to tell small changes especially if you don't have a new one for reference.

Manual trans

Everything moves freely. How do you test the mechanical portion? Just try to turn the cam part manually? I know the vacuum advance plate moves freely when vacuum is applied.

The mechanical parts were all removed, and reinstalled with some grease (light amount of front axle bering grease, which looked very similar to what I cleaned out from it)

 

[miller]

How do you test the mechanical portion?

As mentioned, by rotating the rotor. I have, in a pinch, held a clear degree wheel over the rotor, to get a ballpark on how much advance it gives. Springs should return the rotor to it's starting point.
Lubing the mechanical advance parts...should use a hi-temp grease...only a thin film. That axle grease will probably sling off.
The advance weights, used to see two types, lead or stamps of steel riveted together. For either type, I've always wiped a thin coat of the same grease over them, to keep them clear of corrosion.

Standard trans...some take initial timing at 0.

 

[67 GTX]

As mentioned, by rotating the rotor. I have, in a pinch, held a clear degree wheel over the rotor, to get a ballpark on how much advance it gives. Springs should return the rotor to it's starting point.
Lubing the mechanical advance parts...should use a hi-temp grease...only a thin film. That axle grease will probably sling off.
The advance weights, used to see two types, lead or stamps of steel riveted together. For either type, I've always wiped a thin coat of the same grease over them, to keep them clear of corrosion.

Standard trans...some take initial timing at 0.

Copy, I'll try that.
My weights are multiple pieces held together, but I didn't see any rivets.

Tried initial at 0. Motor didn't like it at all.

 

[miller]

If 12.5 initial works for you, I'd stick with it.
Need to know how much advance in the distributor, and if it's working. That will tell you your full mechanical advance.

 

[Dragon Slayer]

If you have a set of calipers, take the cap and rotor off and measure the cam flat to flat. Should be a about .98"; measure the cam pt to pt. Should be about 1.25". If it is under could be worn, if they read .95 and 1.0. It is a single point distributor cam stop and that may be the problem. You do need to push your gap up with in limit.

Does the car detonate when you add vacuum in?

Right now we are all just shooting around the target and repeating recommendations with guesses.

You have to determine actual Full mechanical advance without vacuum at 3500RPM (should be 28 to 32 degree advance). If we can't measure it we can't really ever get to the bottom of this.

 

[miller]

You do need to push your gap up with in limit.

Off the wall, besides the cam, wondering if it's possible the points are wrong part #. That might explain the odd gapping #s.
Just thinking outloud.

BTW...back into the 67 manual, that particular distributor is not listed, for any 67 engine. Though, could be an alternate #.

 

[HALIFAXHOPS]

Possible damper Slipped? Might be time to verify everything. I would verify TDC on #1 cylinder and go from there. Really a strange issue.

 

[Dragon Slayer]

If you read my post that dist is in the 67 parts manual, but as I said not in the SM. I also stated early on best to go start from the beginning and make sure your at TDC on #1. Check firing order etc... The fact you moved the distributor drive gear to get the distributor to position on the motor is suspect. The distributor should have fit without doing that if the distributor parts are correct for that distributor. The #1 wire would have been on a different position on the cap, but the alignment procedure is the same for either the Chrysler or the Prestolite distributor in the motor section of the SM.

The drive gear slot should run parallel to the cam when #1 piston is at TDC for RB motor. Install distributor with vacuum advance point inward to motor. Where rotor points is #1 wire. Install the rest of the wires in the firing order CCW.

Just not making much sense right now; and folks are repeating recommendations.

 

[miller]

Just not making much sense right now; and folks are repeating recommendations.

Yeah!
How about any updates on what that beast is acting like.
Still the same on the vacuum advance, not doing right? Has to be something...probably simple. Have actual vacuum hose on it??

Gory little details 'can' make the difference on these things. Remember once, on a Mallory, condenser mounted outside the housing, had to replace it. Put the condenser wire on the post, in 'front' of the coil wire lead, and it wouldn't run right!

That Prestolite, has a coil wire, that hooks to both points. Any chance the leads are on backwards? Into the housing, first should go to the primary points, end lead to the secondary. You find the primary, by turning the rotor CCW, and see which set of points open first.
Mechanical advance should move CCW. Vacuum advance should move CCW. All in same rotation.

 

[miller]

Give up??

 

[67 GTX]

Thank for you all the replies. I wasn't by the car this weekend, but now I have some things to check.
I will try to check all of these things tonight and get back to everyone. Thanks for sticking with me here. I am determined to get this working!

That Prestolite, has a coil wire, that hooks to both points. Any chance the leads are on backwards? Into the housing, first should go to the primary points, end lead to the secondary. You find the primary, by turning the rotor CCW, and see which set of points open first.
Mechanical advance should move CCW. Vacuum advance should move CCW. All in same rotation.

I understand that the primary points are the ones that open first during the rotation of the distributor. But how do you then tell which of the leads should be the primary lead? Is the primary one the lead that also goes to the same point as the condensor wire?

Also, would it matter which points the condensor hooks up too?

 

[miller]

Good questions!
I'm going off memory, first car, 63 Sport Fury had a Prestolite dual point. That was back in the 60s, when I had that thing.

That coil wire lead, probably hard to find these days, has a rubber push-in insulator, then into the housing. Two connectors, one at the pigtail, one at the end. Like water through a hose, current through a wire...gets to the pigtail first. Pigtail connector to the primary points.

Is the primary one the lead that also goes to the same point as the condensor wire?

I would think so. Single, or dual points, need the condenser to operate right. If it's connected to the secondary, that only closes the circuit, not right.

Won't hurt to check things. But, in a nutshell, sounds like it's okay, except vacuum advance...

 

[Dragon Slayer]

It does not matter as long as condenser strap or wire does not interfere with the vacuum advance arm. Autolite flipped it at some point. Remember the primary lead has the jumper wire also for dual points. So you have a lead that connects the 2 point sets, and the lead that comes out to the coil. So both points have a path to grounds. One opens and the system is still grounded because the other is still closed. When it opens now there is no longer a ground for the coil and it fires. When that point set that opened first now closes the ground is re-established despite the other point still open. One set opens to fire the coil, the other set closes to charge the coil.

 

[67 GTX]

It does not matter as long as condenser strap or wire does not interfere with the vacuum advance arm. Autolite flipped it at some point. Remember the primary lead has the jumper wire also for dual points. So you have a lead that connects the 2 point sets, and the lead that comes out to the coil. So both points have a path to grounds. One opens and the system is still grounded because the other is still closed. When it opens now there is no longer a ground for the coil and it fires. When that point set that opened first now closes the ground is re-established despite the other point still open. One set opens to fire the coil, the other set closes to charge the coil.

View attachment 673466

That's what I figured. Shouldn't matter since they're all hooked up to the same circuit anyway.

Last night I tried these things are per your recommendations:
Don't have my caliper with me, so couldn't measure the cam (Will do in the coming days)
Dwell was now 42 degrees (at end limit of spec)
I rev'd the motor to 2500 rpm, and with initial at 12.5 BTDC, looks like I got another 12.5 degrees advance (so 25)
While holding motor at 2500 rpm, using a vacuum pump, I slowly provided vacuum to the vacuum advance. Same as before, at around 13-15 in hg, the engine started to get unhappy.

Attached below are some pics of my setup. Please let me know if anything looks off. On the second one, the added electrical tape was put there while I was checking for shorting issues.
I can add bigger pics if needed.

 

[Dragon Slayer]

THat may be normal with that much vacuum. Do this: Attach vacuum gauge to ported vacuum hose (cannister disconnected). Rev to 2500 and read vacuum. You can also read at manifold and compare the 2. How much vacuum at 2500 RPM? On the vacuum cannister arm that attaches to the breaker plate, there should be a number. multiply by 2 and that is the additional maximum advance the vacuum cannister adds to the motor at high vacuum. Cruising at 2500 low load you would have your 25deg from initial and mechanical per your measurement, and higher vacuum because throttle blades are partially closed and then you get additional vacuum advance pushing you out to about 45 degree if the can has a 10 on it. 2x10 plus your 25.

You also can read advance at idle vacuum disconnected. Should be your 12.5, Then using a vacuum pump at idle raise it to 15" and measure timing. If you see 32.5 subtract your 12.5 and that is the timing the vacuum is adding. Again 20 degree.