I challenge you to disable your vac adv & shine the light in the drilled hole in the cap & rev the eng & you will find that phasing does not change. Also move your initial & you also will find that phasing does not change. Only vac adv changes phasing. excellent idea to slot the mounting plate holes on the side of the dist which again will only change the phasing range that vac adv adds. not sure if the vac adv mounting would need to be changed slightly to accomodate this but I am going to do it as I run vac adv. Some mounting plates have a roll pin locator in the housing wall which would need to be removed. on a side not Echlin has a rotor with a longer (.060" iirc) blade which will reduce the gap & help with phasing issues. (MO3000). Robert Crispell Lincoln Nebraska.
Please forgive me, sir, but I don't mean to contradict. I believe that the centrifugal advance will keep the rotor pointing at the same terminal point on the cap but the vacuum advance is the one that will sweep the terminal as you described. I have eliminated the vacuum can and pinned the moveable pickup plate into position to properly index the rotor to the cap on hotrods & racers that way for many years. I then cut off the end of the vacuum can mounting tab to locate the cap on the distributor and cut a piece of aluminum to cover the hole- both the locating tab and the aluminum hole cover mounted by the screws that previously attached the vacuum can unit. The movable pickup mounting plate can easily be pinned at the hole that was previously occupied by the vacuum advance rod after determining rotor index position. Drill through the rod mounting hole into the lower mounting plate and use a small screw/nut (with loc-tite) in the moveable plate extending down into the lower mounting plate to keep moveable plate located. Distributor modified in this fashion will always have rotor pointed exactly where you indexed it determined by the position that you pin the magnetic pickup plate. If you want to use the vacuum advance feature of the distributor THEN you have to deal with the "sweeping rotor" but you can index your rotor for WOT by slotting screw holes as you described if necessary. I hope I didn't offend and I hope even more-so that I'm not incorrect-Haha. There is an awesome advance curve limiting plate available but I can't remember what it's called off hand. It is expensive (approx $50) but SO worth it if you don't have a welder & time/patience to modify centrifugal advance mechanism.
Sorry but you have that inverted. Centrifugal advance rotates the top shaft of the distributor via the weights, so therefore the rotor changes position in relation to the cap terminals. Vacuum advance moves the pickup mounting plate, not affecting rotor position.
Oh and the timing plate comes from 4secondsflat.com (FBO) of which I am a registered distributor for. :-) The plate used to be $22 shipped, but is now $35 shipped.
Sorry, but I still disagree. The rotor moves with the trigger wheel. The plate moves with vacuum advance operation changing position of rotor/terminal relationship. As for price of timing limiter plate I wish I had bought from you.
@@mickangio16 You are correct, he is mistaken...Question: Is rotor phasing being off via factory/design defect really that common? Is it frequently necessary to get an adjustable rotor, an adjustable cap, an adjustable breaker plate or pickup, or a crank trigger? Or are these defects a rare thing? I'm going down a rabbit-hole and I have never heard of phasing being wrong from the factory but I love to learn.
Great video, keep them coming. Quick question about slotting the two screw holes. I understand your reason for doing it I’m just curious would it not change the timing slightly by rotating baseplate?
Loong, long time ago, about 40, 45 years ago an old timer friend of mine told me that 5 and 7 get swapped often doing work. You can tell right away that it's skipping. The reason is because they're the only two cylinders in the firing order on the same bank right next to each other. Real common on Chevs too.
@mopars4us but aren't there pins in the side of the distributor body that locate the base plate? Do you have to remove them to allow for the base plate to rotate when you slot the screw holes?
Thought you were yanking my chain here, but just in case you weren’t. Rotor phasing is not affected by vacuum advance, as vacuum moves the base plate/pickup and not rotor position as it advances.
@@mopars4us If you're going to advise people please reconsider your opinions, rotor phasing doesn't change with mechanical advance, it only makes the spark happen sooner in the engines rotation, the sparks still happen when the rotor is in the same positions, but vacuum advance does make the sparks happen when the rotor is in different positions. The relationship between the shaft and the rotor doesn't change under operation, its fixed.
So basically what you are trying to do is index the rotor to try to be as close to the center of the cap terminal with the reluctor ring in line with the pickup coil, correct?
Only if you have no vacuum advance, if you do have vac adv take the position of the rotor when spark happens with no vacuum advance, and take the position of the rotor when spark happens on full vacuum advance and split the difference between those two positions, making your adjustment to point the middle of the rotor at your new determined point. most likely you'll find that the factory got the phasing pretty darn close. Perhaps it depends on what distributor.
A gap between the rotor and the button in the cap can cause this as a spark that has to jump a gap creates heat. Also Napa carries a rotor that is .030 longer at the tip to help close up that gap between the rotor tip and cap contacts. Part number MO3000
That depends on the distributor. There are many different types of HEI distributors. Some have an adjustable rotor, or an adjustable can be purchased for some.
@@mopars4us i have a MSD street fire. Having some misfires. Took the distributor cap off and noticed that the rotor is firing on the out side of the contacts. I do have retarded initial because of pinging and detonation at higher acceleration. I'm hoping phasing will help. I appreciate your time but do you think phasing my HEI would help? 🤜🤛
@@raymondmenendez6499 Firing on the outside of the contacts could be normal if the mechanical advance causes the rotor tip to sweep across the contacts in the cap.
You're telling me the factories who made certain models of distributors screwed up the rotor phasing so bad that you have to modify the position of the breaker plate/pick-up to correct it? Or get an adjustable rotor, an adjustable cap, an adjustable breaker plate or pickup, or install a crank trigger. I'm thinking this doesn't apply to 99% of classic car people...but cool modification if it really was necessary...btw people, without one of those parts I mentioned THERE IS NO ADJUSTING ROTOR PHASING, just had to be clear.
Great job on explaining this issue and slotting the screw holes is absolutely brilliant 👍👍👍
I challenge you to disable your vac adv & shine the light in the drilled hole in the cap & rev the eng & you will find that phasing does not change. Also move your initial & you also will find that phasing does not change. Only vac adv changes phasing. excellent idea to slot the mounting plate holes on the side of the dist which again will only change the phasing range that vac adv adds. not sure if the vac adv mounting would need to be changed slightly to accomodate this but I am going to do it as I run vac adv. Some mounting plates have a roll pin locator in the housing wall which would need to be removed. on a side not Echlin has a rotor with a longer (.060" iirc) blade which will reduce the gap & help with phasing issues. (MO3000). Robert Crispell Lincoln Nebraska.
Please forgive me, sir, but I don't mean to contradict. I believe that the centrifugal advance will keep the rotor pointing at the same terminal point on the cap but the vacuum advance is the one that will sweep the terminal as you described. I have eliminated the vacuum can and pinned the moveable pickup plate into position to properly index the rotor to the cap on hotrods & racers that way for many years. I then cut off the end of the vacuum can mounting tab to locate the cap on the distributor and cut a piece of aluminum to cover the hole- both the locating tab and the aluminum hole cover mounted by the screws that previously attached the vacuum can unit. The movable pickup mounting plate can easily be pinned at the hole that was previously occupied by the vacuum advance rod after determining rotor index position. Drill through the rod mounting hole into the lower mounting plate and use a small screw/nut (with loc-tite) in the moveable plate extending down into the lower mounting plate to keep moveable plate located. Distributor modified in this fashion will always have rotor pointed exactly where you indexed it determined by the position that you pin the magnetic pickup plate. If you want to use the vacuum advance feature of the distributor THEN you have to deal with the "sweeping rotor" but you can index your rotor for WOT by slotting screw holes as you described if necessary. I hope I didn't offend and I hope even more-so that I'm not incorrect-Haha. There is an awesome advance curve limiting plate available but I can't remember what it's called off hand. It is expensive (approx $50) but SO worth it if you don't have a welder & time/patience to modify centrifugal advance mechanism.
Sorry but you have that inverted.
Centrifugal advance rotates the top shaft of the distributor via the weights, so therefore the rotor changes position in relation to the cap terminals.
Vacuum advance moves the pickup mounting plate, not affecting rotor position.
Oh and the timing plate comes from 4secondsflat.com (FBO) of which I am a registered distributor for. :-)
The plate used to be $22 shipped, but is now $35 shipped.
Sorry, but I still disagree. The rotor moves with the trigger wheel. The plate moves with vacuum advance operation changing position of rotor/terminal relationship. As for price of timing limiter plate I wish I had bought from you.
@@mickangio16 You are correct, he is mistaken...Question: Is rotor phasing being off via factory/design defect really that common? Is it frequently necessary to get an adjustable rotor, an adjustable cap, an adjustable breaker plate or pickup, or a crank trigger? Or are these defects a rare thing? I'm going down a rabbit-hole and I have never heard of phasing being wrong from the factory but I love to learn.
Great video, keep them coming.
Quick question about slotting the two screw holes. I understand your reason for doing it I’m just curious would it not change the timing slightly by rotating baseplate?
Absolutely changing the plate changes the timing.
It needs to be re set.
Loong, long time ago, about 40, 45 years ago an old timer friend of mine told me that 5 and 7 get swapped often doing work. You can tell right away that it's skipping. The reason is because they're the only two cylinders in the firing order on the same bank right next to each other. Real common on Chevs too.
We need clear see through dist. Caps!!!
@mopars4us but aren't there pins in the side of the distributor body that locate the base plate? Do you have to remove them to allow for the base plate to rotate when you slot the screw holes?
Some have the pin and some don’t.
If a person wants to make the phasing adjustable, the pin needs to be removed if it has one.
You are correct.
@@mopars4us Ah, thank you for explaining that. This was a great video!! I learned something as it apples to Mopar distributors. Thanks!
How to adjust phasing with a vacuum valve should be your next upload.
Thought you were yanking my chain here, but just in case you weren’t.
Rotor phasing is not affected by vacuum advance, as vacuum moves the base plate/pickup and not rotor position as it advances.
@@mopars4us If you're going to advise people please reconsider your opinions, rotor phasing doesn't change with mechanical advance, it only makes the spark happen sooner in the engines rotation, the sparks still happen when the rotor is in the same positions, but vacuum advance does make the sparks happen when the rotor is in different positions. The relationship between the shaft and the rotor doesn't change under operation, its fixed.
Thanks for the info. Appreciate your time
Thanks for this video. I always wondered about this.
Thank you, I hope it helps you in the future.
So basically what you are trying to do is index the rotor to try to be as close to the center of the cap terminal with the reluctor ring in line with the pickup coil, correct?
Sorry, I didn’t see this for some reason.
Yes, that is correct.
Only if you have no vacuum advance, if you do have vac adv take the position of the rotor when spark happens with no vacuum advance, and take the position of the rotor when spark happens on full vacuum advance and split the difference between those two positions, making your adjustment to point the middle of the rotor at your new determined point. most likely you'll find that the factory got the phasing pretty darn close. Perhaps it depends on what distributor.
Preparation is the key to life
What would cause a rotor to overheat and burn the insulation right through, but no misfire,.. After fitting and msd 6 series ignition box
A gap between the rotor and the button in the cap can cause this as a spark that has to jump a gap creates heat.
Also Napa carries a rotor that is .030 longer at the tip to help close up that gap between the rotor tip and cap contacts.
Part number MO3000
Is it possible to adjust phasing on a HEI distributor?
That depends on the distributor.
There are many different types of HEI distributors.
Some have an adjustable rotor, or an adjustable can be purchased for some.
@@mopars4us i have a MSD street fire. Having some misfires. Took the distributor cap off and noticed that the rotor is firing on the out side of the contacts. I do have retarded initial because of pinging and detonation at higher acceleration. I'm hoping phasing will help. I appreciate your time but do you think phasing my HEI would help? 🤜🤛
@@raymondmenendez6499
Firing on the outside of the contacts could be normal if the mechanical advance causes the rotor tip to sweep across the contacts in the cap.
@@mopars4us thank you for your time 🖖
You're telling me the factories who made certain models of distributors screwed up the rotor phasing so bad that you have to modify the position of the breaker plate/pick-up to correct it? Or get an adjustable rotor, an adjustable cap, an adjustable breaker plate or pickup, or install a crank trigger. I'm thinking this doesn't apply to 99% of classic car people...but cool modification if it really was necessary...btw people, without one of those parts I mentioned THERE IS NO ADJUSTING ROTOR PHASING, just had to be clear.
Thank you!
WRONG, the ANGLE is FIXED between the Rotor Button Tip AND the Reluctor / Pole Piece.
Appreciate this. (318)