Rotor position in 426 hemi dual distribtutor

[Dean Prevolos]

I was watching a YOUTUBE video on installing a distributor in a big block. I have a 426 Hemi, first time for me, and I had posted months ago a question on setting my dual point distributor into the engine. I understood that I was to make sure that the oil gear drive was set in with the "slot" front-to-back at TDC. Drop in distributor with rotor pointing to #1 spark plug.

I have done that and am having trouble with the car not starting. So I have set and re-set everything we all do in troubleshooting.

But I just watched a YOUTUBE MOPAR video" How to Installa Distributor" and he has the fat end of the rotor pointing toward the #1 spark plug, he calls it the mushroom side of the rotor. Is that correct? A few comments on the video told him he was wrong and I have never seen that done before on other engines BUT I have never had a 67 Hemi with the original dual point distributor. Can someone set me straight on which end of the rotor should point toward the #1 spark plug?

Read the comment below posted by the YOUTUBE GUY to another party who questioned his video:
NOPE Sorry Your Wrong Man....Big "Blunt Mushroom end points at number #1" on a Big Block! The Car Fired right up in an instant after this.....if you point the distributor as you are saying you would be 180* out and blow flames through your carb and car would never start. NOW on a GM you want pointed end to #1 but MOPAR is opposite!

 

[HALIFAXHOPS]

OK the copper tip should point to #1 cyl cap terminal. Lots of variables here. Make sure the enginge is set to TDC, not 180 out, make sure your slot is aligned per FSM. Now the fun. You sure the distributor is 100% correct for the tag? There is alot of retagging of them since they are not cheap. Now the distributor shaft is clocked for that number, same as the advance cam. So it can have the slot lined up but the internals of the distributor wont let the rotor point to number one wire if that makes sense. Hope it helps.

 

[Dean Prevolos]

OK the copper tip should point to #1 cyl. Lots of variables here. Make sure the enginge is set to TDC, make sure your slot is aligned per FSM. Now the fun. You sure the distributor is 100% correct for the tag? There is alot of retagging of them since they are not cheap. Now the distributor shaft is clocked for that number, same as the advance cam. So it can have the slot lined up but the internals of the distributor wont let the rotor point to number one wire if that makes sense. Hope it helps.

Sure that helps and I do have the copper tip pointing to #1. I was just curious about the guy saying the back side of the rotor should point to the #1 spark plug, never heard of that or seen that.

 

[HALIFAXHOPS]

Only way that will work is if the TDC is 180 out did you verify #1 piston is up all the way with the valves closed? Easy to set TDC 180 out.

 

[HALIFAXHOPS]

I sent you my # call me fast way easier.

 

[Beekeeper]

Dean,
I didnt notice you had two post so check you other post.

 

[Beekeeper]

Drop it in this position with #1 at TDC on the firing stroke and make sure your plug wires are correct and it will fire up. you may need to advance or retard the timing but it will run if it has fuel and spark. Also I would recommend that you don’t watch that guy on YouTube he’s clueless.

 

[pnora]

The u-tube idiot has it on the exhaust stroke with the timing mark lined up. So next revolution its on TDC compression stoke and will run. Its not rocket science or magic. As long as the rotor is at number one on the end of the compression stroke and there is room to adjust the timing it works. It does not mater where you drop the distributor or drive gear in. You just orient the wires on the cap to work off that position. Its nice to do it the way they left the factory. Myself I always do it like the factory.

 

[Dean Prevolos]

Okay so this morning I went through everything and I was checking to see if I had spark when I opened the secondary set of points and blocked the primary points with a piece of cardboard. what I found was when the secondary set of points go to open they're hitting the set screw that's holding the points into the distributor plate. I tightened it thinking that would then clear but it's still hitting the screw head. so either the set up new points that I have are wrong or I need a new set screw that has a flat side to it. And I agree with everyone the guy and YouTube doesn't know what he's talking about. I have never seen anybody set up a rotor that way. That's why I was totally taken aback by his process of installing his distributor. So I have the distributor installed correctly and I have the rotor installed correctly. I will take the distributor out and install the points while it's sitting in my vice with correct screw. Then my points should work and the car should start. I was confused why my meter kept showing the points grounding out when I turned the key and cranked it. Now I know. Thanks for all your help.

 

[Cranky]

Okay so this morning I went through everything and I was checking to see if I had spark when I opened the secondary set of points and blocked the primary points with a piece of cardboard. what I found was when the secondary set of points go to open they're hitting the set screw that's holding the points into the distributor plate. I tightened it thinking that would then clear but it's still hitting the screw head. so either the set up new points that I have are wrong or I need a new set screw that has a flat side to it. And I agree with everyone the guy and YouTube doesn't know what he's talking about. I have never seen anybody set up a rotor that way. That's why I was totally taken aback by his process of installing his distributor. So I have the distributor installed correctly and I have the rotor installed correctly. I will take the distributor out and install the points while it's sitting in my vice with correct screw. Then my points should work and the car should start. I was confused why my meter kept showing the points grounding out when I turned the key and cranked it. Now I know. Thanks for all your help.

Like Pnora said.....it doesn't matter where the rotor is pointing so long as the wires are in 'tune' with the rotor and it's at TDC when you install the wires. Man, been way too long since I messed with a dual point setup but probably won't go back to them. Last of the cars with points left here around 2000 or so. My 66 had them until 98 when I pulled the engine and well, it's still sitting heartless.

 

[pedal2themetal]

HI .. do you know that TDC on the crank comes up twice to ONE turn of the distributor.. so at one time TDC well line up with #1 in the cap and one more turn the TDC it well be 180* out of time. I think the oil pump shaft is the same shape on it (like a rectangle) so the distributor could be put in 180* out if the crank is not at the proper TDC of the compression stroke.

good luck take care be safe
tim

 

[Beekeeper]

Okay so this morning I went through everything and I was checking to see if I had spark when I opened the secondary set of points and blocked the primary points with a piece of cardboard. what I found was when the secondary set of points go to open they're hitting the set screw that's holding the points into the distributor plate. I tightened it thinking that would then clear but it's still hitting the screw head. so either the set up new points that I have are wrong or I need a new set screw that has a flat side to it. And I agree with everyone the guy and YouTube doesn't know what he's talking about. I have never seen anybody set up a rotor that way. That's why I was totally taken aback by his process of installing his distributor. So I have the distributor installed correctly and I have the rotor installed correctly. I will take the distributor out and install the points while it's sitting in my vice with correct screw. Then my points should work and the car should start. I was confused why my meter kept showing the points grounding out when I turned the key and cranked it. Now I know. Thanks for all your help.

The points are grounded to the distributor plate and the plate is grounded to the housing and the housing is grounded to the block so it’s normal to read to ground through the points when they are closed. I agree they should not be hitting the screw so that does need correcting that would cause the moving contact to be grounded when it shouldn't be. Also be sure that the gasket for the housing to block is the steel one and not the paper one otherwise your distributor will not be grounded to the block properly.

 

[Dean Prevolos]

The points are grounded to the distributor plate and the plate is grounded to the housing and the housing is grounded to the block so it’s normal to read to ground through the points when they are closed. I agree they should not be hitting the screw so that does need correcting that would cause the moving contact to be grounded when it shouldn't be. Also be sure that the gasket for the housing to block is the steel one and not the paper one otherwise your distributor will not be grounded to the block properly.

The gasket for the distributor is not metal it is some sort of a paper ring. Can I put it in without the gasket today so it grounds to the block?

 

[Dean Prevolos]

Drop it in this position with #1 at TDC on the firing stroke and make sure your plug wires are correct and it will fire up. you may need to advance or retard the timing but it will run if it has fuel and spark. Also I would recommend that you don’t watch that guy on YouTube he’s clueless.
View attachment 1303907

That is what I was looking for from someone on the forum . Thank you very much because I had my rotor pointing to the number one spark plug but my #1 spark plug was on the wrong side.

 

[Fran Blacker]

Wouldn't the hold down clamp and or bold grond dist? If had a thick coat of paint you'd need to clean it off.

 

[Dean Prevolos]

Drop it in this position with #1 at TDC on the firing stroke and make sure your plug wires are correct and it will fire up. you may need to advance or retard the timing but it will run if it has fuel and spark. Also I would recommend that you don’t watch that guy on YouTube he’s clueless.
View attachment 1303907

 

[Dean Prevolos]

View attachment 1304036

I'm in

 

[Beekeeper]

The gasket for the distributor is not metal it is some sort of a paper ring. Can I put it in without the gasket today so it grounds to the block?

Change that gasket Ray (@HALIFAXHOPS)has the correct one. Yea you can run for a little bit without it just a chance of a bit of oil seepage but it wouldn’t be much if any for a short period.

 

[Dragon Slayer]

Dean, late in reading this, but that looks right for the hemi, #1 is second post down from the clamp and your vacuum advance pointing across motor. The hemi has limited area for adjusting timing without hitting vacuum can on manifold or fuel lines. Hence the tip configuration Halifax mentioned. When I redid my distributor, my drive gear was clocked wrong.

Once you're on TDC for #1 you make sure drive gear slot as you mentioned. Installing distributor as you did with rotator down towards passenger side front.

What I like to do after that (with plugs out) is rotate motor coming back to TDC on #1 but stop at 10 degree BTDC. At that point put a voltmeter on the distributor lead and other to ground. Rotate distributor slightly until points just open and meter goes from 0 ohms to open on #1. At that point you have a basic initial timing set at 10deg BTDC. Tighten up and ready to start. Once running and warmed up you can set initial to what you want.

For electronic you can do the same except it is visual with the rotor tip just at the magnet core. The electronic distributor fire as the reluctor tip just passes the core.

 

[Dean Prevolos]

Dean, late in reading this, but that looks right for the hemi, #1 is second post down from the clamp and your vacuum advance pointing across motor. The hemi has limited area for adjusting timing without hitting vacuum can on manifold or fuel lines. Hence the tip configuration Halifax mentioned. When I redid my distributor, my drive gear was clocked wrong.

Once you're on TDC for #1 you make sure drive gear slot as you mentioned. Installing distributor as you did with rotator down towards passenger side front.

What I like to do after that (with plugs out) is rotate motor coming back to TDC on #1 but stop at 10 degree BTDC. At that point put a voltmeter on the distributor lead and other to ground. Rotate distributor slightly until points just open and meter goes from 0 ohms to open on #1. At that point you have a basic initial timing set at 10deg BTDC. Tighten up and ready to start. Once running and warmed up you can set initial to what you want.

For electronic you can do the same except it is visual with the rotor tip just at the magnet core. The electronic distributor fire as the reluctor tip just passes the core.

Thank you for the tip on the advance timing and the #1 post. I think I have the #1 at the first post down from the clamp. I will check this morning. By the way, it turns out that with all the questions I had with my distributor, it turns out that my fuel pump was not working. I removed it after testing for vacuum on the fuel side and had zero, needle didn't even move. I removed last night and rebuilt the pump. Whomever had the pump before me had removed the mesh screen and the inside of the pump looked like it was "sand-blasted" . Today I will give it another try. I will let you know how it bgoes. Thanks again for your advise, much appreciated.