Need Dual Point Assistance

[miller]

Now, with the exact same initial setting, with the dual point distributor, the car doesn't start as quickly. Not sure why.

The why is, two different distributors, most likely two different advance degrees/curve.

So the distributor is making 14* mechanical.

Is it? You figure the base # for initial, knowing your 'on the plate' advance.

Something you might try...use a clear plastic degree wheel, held over the rotor, to see how many degrees it moves, when it goes to full advance. Example...mine moves 11 degrees, X2 means on the plate it has 22 degrees.
Need that on the plate #. On your Prestolite, it's fixed by the plate that's installed. To change that number of degrees, plate has to be changed.

Total advance of 36, minus the 'on the plate' advance degrees, equals the initial degree timing.
Your point gap/dwell is another issue. (I kinda remember .017" - .018")

 

[Dragon Slayer]

Did you ever take the test drive yet with vacuum attached? Your starting to get conflicting information and of course some issues I thought you had resolved, may not have been resolved. Again, this is a used distributor. Prestolite does not have mechanical advance stamped on the cam like Chrysler's do. Also, because this is a 50+ yo used one the slots can be worn open meaning more mechanical advance available. Did you measure cam stop flat to flat and pt to tp width?

We can be doing this for weeks/months, or you really need to go back and start over. Get the motor on TDC for firing. Line up the Distributor drive gear per SVM. Install Distributor per SVM, and where the rotor points is #1 plug wire. Won't be same location as your chrysler distributor. Install rest of wires in CCW rotation per firing order. Have points in spec. Test dwell. If you can not get the correct dwell with out lowering point gap, your CAM Stop is suspect.

This pretty much a stock motor right? So the car should do fine with any combination of Initial and Mechanical between 30-34 degree and vacuum disconnected. Which I think you have right? This should be tested on the road low speed cruise, high speed cruise, some acceleration at WOT from low speed and mid speed. If that is all good we can work vacuum, but if your still at low gap to get spec dwell, that may be a problem you will see at higher speed.

You also have to be able to take good timing measurements. Even if that means getting a tape and putting on Balancer. Then you can truly measure full advance at high RPM no vacuum making sure your less than 34 degrees. Then at idle you can use your vacuum pump to apply vacuum at see if it adds timing at the correct vacuum spec per the SVM. And how much total it can add at full vacuum. Also, that vacuum advance comes off smoothly as you lower vacuum. Some where something is going to come up out of spec.

Can ticking be valve train/lifters? I do not think that is pinging or detonation.

 

[67 GTX]

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.

It's been raining pretty heavily and consistent lately here, so I haven't taken the car out. I was able to get a decent dimensional measurement yesterday. Not fully convinced that my point to point measurement was entirely accurate, but here is what I got:
Flat to flat: .986
Point to point: 1.073

Could that be the reason for some of my issues?

 

[miller]

Point to point: 1.073

Dragon says 1.25". Big difference.

Looked over your pics, again. Points on the cam a little burned? Notice dark areas on top of points. A little more detective work needed. Maybe a good used cam shaft?

Did you have the original vacuum advance can? If so, what # on the arm? Seems most of your issues are with the vacuum advance.

 

[67 GTX]

Dragon says 1.25". Big difference.

Looked over your pics, again. Points on the cam a little burned? Notice dark areas on top of points. A little more detective work needed. Maybe a good used cam shaft?

Did you have the original vacuum advance can? If so, what # on the arm? Seems most of your issues are with the vacuum advance.

Does anyone remanufacture new cams for dual point distributors?

The points are brand new. If they look burned, that happen in under 100 miles since install.

The original arm that came on the distributor (not the one I have installed) had a 10 stamped on its arm.

 

[Fran Blacker]

Does anyone remanufacture new cams for dual point distributors?

The points are brand new. If they look burned, that happen in under 100 miles since install.

The original arm that came on the distributor (not the one I have installed) had a 10 stamped on its arm.

Arm on vacuum advance? Think Tony's Parts is repo ing the vacuum advance chambers.

 

[Dragon Slayer]

Flat to Flat is good, but the point to point should be greater. A single point cam has a pt to pt of about .995". Could just be how your measuring or it is really worn. Certainly would contribute to why you need such a small gap to get the dwell right. G

 

[khryslerkid]

Dragon says 1.25". Big difference.

Certainly would contribute to why you need such a small gap to get the dwell right.

I was wondering when he set his points at .010 and came up with 26* dwell if there was something causing this.

 

[miller]

The points are brand new. If they look burned, that happen in under 100 miles since install.

Probably used the wrong word. No, not the points themselves...mean the 'points' on the distributor cam. Comparing how it looks, from other Prestolite cams, profile looks okay. Point to point measurement maybe part of the problem. Honestly, never ran into a points cam badly wore out, usually fairly hard. Points followers (rubbing finger, or however you want to call it), is the normal wearing part.
IF that cam is wore that much, my guess would be, the points would have a wider 'peak' on them.

Does anyone remanufacture new cams for dual point distributors?

It would need to be for a Prestolite. Not that I know of. Same part includes the advance slots.

 

[67 GTX]

Probably used the wrong word. No, not the points themselves...mean the 'points' on the distributor cam. Comparing how it looks, from other Prestolite cams, profile looks okay. Point to point measurement maybe part of the problem. Honestly, never ran into a points cam badly wore out, usually fairly hard. Points followers (rubbing finger, or however you want to call it), is the normal wearing part.
IF that cam is wore that much, my guess would be, the points would have a wider 'peak' on them.


It would need to be for a Prestolite. Not that I know of. Same part includes the advance slots.

Weather improved so I will try some other things if I can.

I bought a cast iron dual point that was supposedly off of a 62 Imperial with a 413. I wonder if that cam will work (and act the same proper way as what mine should be).

 

[Fran Blacker]

Have 2642899 dist, measured rubb1ng block high to high spot 1.25 low to low .98. Vacuum arm 11. Can't say unmolested for sure bought as a parts dist. Tomorrow will pull it apart to see what's stamped on it if you want?

 

[67 GTX]

Have 2642899 dist, measured rubb1ng block high to high spot 1.25 low to low .98. Vacuum arm 11. Can't say unmolested for sure bought as a parts dist. Tomorrow will pull it apart to see what's stamped on it if you want?

Don't go out of your way, but if you could I would appreciate it. It'll give me some more knowledge on maybe what I "should" have.

 

[Fran Blacker]

Yes I'll pop it apart and some pic's.

 

[Dragon Slayer]

As you see from Fran, the DP cam stop have the same flat to flat and Pt to Pt as I mentioned. What your going to find different is the clocking of the Flat spot for the rotor. So pay attention as it will drive a new location for #1 wire. Looking at your cam stop picture closer I believe it may be a "max wedge". The Flat is at 3 O'Clock with the E. I have one like it. Believe your will find a LG letter under the bottom. (going off memory here) Can check notes later. That is why you had to change the position of your distributor drive shaft to get the distributor lined up. Though you could have just changed wire positions.

It will work, I would go to the service manual for that distributor and you can find the mechanical advance measurement. You can install that cam stop in your current distributor just watch for the new rotor position.

If it was me, and I am just making a recommendation, since you have to pull the distributor again. Get the car on TDC for #1. Get your drive gear realigned to SVM parallel to CAM and Crank Shaft. Basically slot going front to rear of car. When you install the distributor install with vacuum facing inward towards centerline. With Rotor pointing just CW after the forward most clip. Where ever it lines up in that general area. At that point that is #1 wire location. This should put you close to how it came from the factory.

I think you can dial in about 10-12 degree Initial and test it out.

 

[Fran Blacker]

Dragon Slayer cam stops are the slots for stopping the advance weights, correct? The SS cam stops were angled not straight so full mechanical advance with two light springs was in at 1000 rpm? If I can find it I'll get a pic of that. Seen pictures in other threads of different cams.

 

[Dragon Slayer]

Mopar calls it a cam stop. My mistake I meant max wedge not super stock. The IBB-4202 Max wedge no vacuum had the E straight slot cam stop as pictured. Your correct the Super Stock had the A angled slot cam stop IBB-4204 also no vacuum advance.

 

[oldbee]

I’m getting ‘dizzy’, but clean off balancer of rust,etc. and put on a timing tape. Mine has lasted for 30+ years, makes things easy.

 

[miller]

I bought a cast iron dual point that was supposedly off of a 62 Imperial with a 413.

The about right application would work, both the 413 and 440 being RB motors. But, the distributor cam measurements, I'll have to wait, for more info. (Still doesn't have anything to do with what your vacuum advance is doing.)

My problem...always had my hands on units, with the 'stock' parts in them.
Your's, fifty years old, flat no telling what all has been done to it, including tossing in off the shelf parts, to make it whole. Can't say positive that's the case. Unfortunately, unless you have good parts lists/data, that's hard to find these days. Those distributors are considered obsolete! Doesn't mean not usable.
Hard to find much good info, even on my blasted Mallory.

 

[miller]

Okay. Kicked some of the cobwebs out, being the old guy I am.

Meant to do this earlier. Have both 64 and 65 service manuals. Looked up distributors in the 65. Might not be the same number, your's being maybe a 62 model, but workings are the same. Dual point Prestolite in there, for the 426 wedge.

Ignition numbers, the same as I remember, for my aluminum Prestolite, on my 63. For what it's worth...

Points gap - .014" - .019" (always gaped mine .018")
Dwell - each 27* - 31*, both (total) 36* - 40*
Initial Timing - 10* BTC

 

[67 GTX]

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.

Where did you get those cam dimension numbers from?

Last night I was able to work on that car. I hooked up the vacuum advance, and attempted to take the car for a drive. But, it was not going to happen. Car instantly was running extrememly rough.

So I swapped back my older distributor. I had to reindex the cam gear 2 positions counter clockwise (the bottom is hex going to the oil pump, so that is what I mean by 2 of those positions).

With the dual point out, I took some more accurate measurements on the cam stop
flat to flat: .986
point to point: 1.03

On the distributor that I put back in, which is a single point, here are the specs that I took off it:
flat to flat: .958
point to point: .997
Vacuum arm: 7.5L
Points gap: smaller than .008
Dwell: 30*

Now the cam appears to be in spec from what I've read here, so why is such a small gap giving the proper dwell on this distributor too? The car runs fine with this one (with the vacuum advance hooked up).