[withac]

I've searched here, looked on YouTube, and almost every set of instructions on replacing a distributor (I've got an HEI) starts with find plug #1 or TDC. If I don't move anything or turn it over, why can't I just mark the position of the vacuum advance, the position of the rotor, both before and after I lift out the dizzy, line up the VA with where the old one was, line up the rotor with the mark where it rotated to after lifting the old one out, and ease the new dizzy into place?

I've never done this before so this is all new, but if the new one is in the same orientation as the old one, shouldn't it be good to go as far as firing order? Then work on fine tuning the timing and advance?

Thanks

[Fred Ficarra]

Sounds OK, but finding TDC on the compression stroke is a good safety net and easy to do.

[withac]

Originally Posted by Fred Ficarra

Sounds OK, but finding TDC on the compression stroke is a good safety net and easy to do.

Thanks, but if I do that now the rotor and everything won't line up with the original marks, right? If I do that then I've got to find plug one, which isn't hard, and line the rotor up with that, right? And short of pulling all the plugs so I can turn it over by hand and not fight the compression, how do you turn it in small increments short of repeatedly bumping the starter till it stops where you want? Sorry if this is all obvious to everyone else but it's new to me.i was hoping to carefully lift one out and carefully slide one in and be done.

[Fred Ficarra]

Relax, you were on the right track. Finding TDC is just to insure there's a backup plan in case you need a proper reference such as if your marks get wiped off.
Personally I can't imagine pulling a distributor without #1 at TDC. But that's just me. Or is it?
And yes, just have a helper bump the starter. Then make sure the rotor is pointed at the #1 plug wire, not 180° out. But that'll work too.
Go for it. Not rocket science.

[wiskeesour]

Originally Posted by withac

I've searched here, looked on YouTube, and almost every set of instructions on replacing a distributor (I've got an HEI) starts with find plug #1 or TDC. If I don't move anything or turn it over, why can't I just mark the position of the vacuum advance, the position of the rotor, both before and after I lift out the dizzy, line up the VA with where the old one was, line up the rotor with the mark where it rotated to after lifting the old one out, and ease the new dizzy into place?

I've never done this before so this is all new, but if the new one is in the same orientation as the old one, shouldn't it be good to go as far as firing order? Then work on fine tuning the timing and advance?

Thanks

Ive done this several times exactly like this. 9-10 times i miss something. Find TDC with old dizzy THEN drop new one. Lots easier & less troubleshooting if you miss something later. Pull #1 plug, use screwdriver or similiar to poke a rag in #1 hole then bump till rag 'pops' out. EZ. Good luck.

[Steptoe]

What ever u do... Set the engine to TDC as Fred says, remove the key from the ign and hide it in a dark place.
No u cant simply pull the old out and put the new in.
1/ often the slot bit in the top of the oil pump down inside the engine twists slightly and may need realigning to get #1 to the front a VA pionting in the right direction...look at the bottom of the new dizzy and u will see where ot goes in the bottom of the shaft.
2/ The new dizzy will be sligtly different configuration in side because of a different VA with a different length arm that sets the intial timing in a different place.
3/The amount of degrees in the counterweight part of the new dizzy will be VERY diffrent, as will the weight of the springs that determine the rate of advance against rpms
4/The VA will also have very different configuration, not just the number of degrees in it but the amount of Vaccuum required for it to start to advance and the piont at which it finishes... this will also require re configuring...this also refers back to 1/

If one refers to the AC/Delco electrical service manual there are literally 1000s of dizzies, all different specs, then combine those with 100s of VA specs...each combo for different vechiles of different weights, different rear axle/ gear box combos, different wheel diameters , different engine power and sizes , and different end use of the vechilce.
Therefore it is impossble (and uneconomical to produce) to simply buy a 'matching' dizzy out of the box and drop in.
If your orginal dizzy has been dialed into to your engine , to take account of any rebuils, rebores etc, the very different fuels we now use....
Simply take a bit of graph paper and a timing light and re graph what is in the current dizzy, and note the VA specs...then reproce those onece back in the car by filling off counter weight tails, changinf springs and adjusting the VA and setting the intial timing position.
IF it has never been dialed in , then to do so u will have to make sure that there are no vaccuum leaks, establish that the carb is dialed in with O2 sensors , data loggers under load, cruise and idle...THEN establish yout tuning pionts in the timing. intial , idle, total, and amount of VA.
It also very highly recommended that all new HT leads, spark plugs shuld be installed so get correct readings.
Tools ..
9/16 ring spanner
Timing light
O2 sensor and data logger
hand vaccuum pump
tape for the Harmonic balancer to extend the timing marks out to 40 degs
Graph paper and pen.

We look at out lumps of cast iron and very rarely appreciate the presion settings and engineering that goes in to them....machining down to fractions of 1/1000"
Carb jets and setting even smaller
Timing to hit the max piont of explosion at the correct piont at a given load and rpms in a narrow 'window ' of 12 to 18 degs ATDC +/- 1 deg or less.

Funny how we spend hrs getting panels lined up down to small fractions of an inch to look good, and so many dont give a damn after spending so much money and time of having the engine run as well...

I dont want to put u off....we have talked , many times, in old posts , members who have never done stuff before, suspenstion , brakes, panels, welding.....and dialing in engines...this is what this communty is about.

[withac]

Originally Posted by Steptoe

What ever u do... Set the engine to TDC as Fred says, remove the key from the ign and hide it in a dark place.
No u cant simply pull the old out and put the new in.
1/ often the slot bit in the top of the oil pump down inside the engine twists slightly and may need realigning to get #1 to the front a VA pionting in the right direction...look at the bottom of the new dizzy and u will see where ot goes in the bottom of the shaft.
2/ The new dizzy will be sligtly different configuration in side because of a different VA with a different length arm that sets the intial timing in a different place.
3/The amount of degrees in the counterweight part of the new dizzy will be VERY diffrent, as will the weight of the springs that determine the rate of advance against rpms
4/The VA will also have very different configuration, not just the number of degrees in it but the amount of Vaccuum required for it to start to advance and the piont at which it finishes... this will also require re configuring...this also refers back to 1/

If one refers to the AC/Delco electrical service manual there are literally 1000s of dizzies, all different specs, then combine those with 100s of VA specs...each combo for different vechiles of different weights, different rear axle/ gear box combos, different wheel diameters , different engine power and sizes , and different end use of the vechilce.
Therefore it is impossble (and uneconomical to produce) to simply buy a 'matching' dizzy out of the box and drop in.
If your orginal dizzy has been dialed into to your engine , to take account of any rebuils, rebores etc, the very different fuels we now use....
Simply take a bit of graph paper and a timing light and re graph what is in the current dizzy, and note the VA specs...then reproce those onece back in the car by filling off counter weight tails, changinf springs and adjusting the VA and setting the intial timing position.
IF it has never been dialed in , then to do so u will have to make sure that there are no vaccuum leaks, establish that the carb is dialed in with O2 sensors , data loggers under load, cruise and idle...THEN establish yout tuning pionts in the timing. intial , idle, total, and amount of VA.
It also very highly recommended that all new HT leads, spark plugs shuld be installed so get correct readings.
Tools ..
9/16 ring spanner
Timing light
O2 sensor and data logger
hand vaccuum pump
tape for the Harmonic balancer to extend the timing marks out to 40 degs
Graph paper and pen.

We look at out lumps of cast iron and very rarely appreciate the presion settings and engineering that goes in to them....machining down to fractions of 1/1000"
Carb jets and setting even smaller
Timing to hit the max piont of explosion at the correct piont at a given load and rpms in a narrow 'window ' of 12 to 18 degs ATDC +/- 1 deg or less.

Funny how we spend hrs getting panels lined up down to small fractions of an inch to look good, and so many dont give a damn after spending so much money and time of having the engine run as well...

I dont want to put u off....we have talked , many times, in old posts , members who have never done stuff before, suspenstion , brakes, panels, welding.....and dialing in engines...this is what this communty is about.

Thanks again. At first I was just going to do a tune up kit, it needs a new cap, rotor, and pig tail, but when I looked deeper the mounting holes in the MA weights are worn as are the pins they mount on. At that point I decided I'd just as well replace the whole thing. The tune up kit I could have handled, I'm starting to wonder if I should just have my mechanic swap the dizzy's, I really don't want to screw anything up and this isn't the car to learn on.

[Vega$69]

Originally Posted by withac

Thanks again. At first I was just going to do a tune up kit, it needs a new cap, rotor, and pig tail, but when I looked deeper the mounting holes in the MA weights are worn as are the pins they mount on. At that point I decided I'd just as well replace the whole thing. The tune up kit I could have handled, I'm starting to wonder if I should just have my mechanic swap the dizzy's, I really don't want to screw anything up and this isn't the car to learn on.

You had it right to start with. In fact you pretty much quoted MSDs intstuctions for swapping out the dizzy.

Yes it is that simple

[novaderrik]

as long as the old one is lined up, then the new one will line right up, too. just keep in mind that # 1 on a points distributor is supposed to be at a different terminal than an HEI and custom fit plug wires are made accordingly. the distributor still drops right in, but the rotor is pointed at a different terminal and you may have to bump the starter to get the oil pump drive to engage.

also, make sure you have a timing light handy to properly set the timing once you have it running.

[Melrose RS]

Originally Posted by novaderrik

you may have to bump the starter to get the oil pump drive to engage

Argeed. This is a key point. If you have the rotor lined up and the dist wont drop in fully, leave it and just rotate the engine by hand. The rotor will turn in synch and the dist will drop once the oil pump drive aligns. No voodoo. Dont be afraid to mess it up.



Sent from my iPhone using Autoguide

[withac]

Originally Posted by novaderrik

as long as the old one is lined up, then the new one will line right up, too. just keep in mind that # 1 on a points distributor is supposed to be at a different terminal than an HEI and custom fit plug wires are made accordingly. the distributor still drops right in, but the rotor is pointed at a different terminal and you may have to bump the starter to get the oil pump drive to engage.

also, make sure you have a timing light handy to properly set the timing once you have it running.

Thanks. Both old and new are HEI. If I follow what I've read, once I have it running as long as I don't stand on it to bring the VA into play or go too fast to max out the mech adv I thought I could just idle it down the road to my mechanic who lives close and have him polish off the timing. Or even get him to come to my house.

[Vega$69]

Originally Posted by withac

Thanks. Both old and new are HEI. If I follow what I've read, once I have it running as long as I don't stand on it to bring the VA into play or go too fast to max out the mech adv I thought I could just idle it down the road to my mechanic who lives close and have him polish off the timing. Or even get him to come to my house.

Timing is the easy part that takes about 2 minutes.

Grab a light, plug the VA, turn dizzy as needed to get about 12* at the timing indicator and tighten dizzy in place. Check after tighten with light to make sure it didn't move.

Here you go

How to Set the Ignition Timing on Your Car's Engine - YouTube

How to Set the Ignition Timing on Your Car's Engine - YouTube

[withac]

Originally Posted by Vega$69

Timing is the easy part that takes about 2 minutes.

Grab a light, plug the VA, turn dizzy as needed to get about 12* at the timing indicator and tighten dizzy in place. Check after tighten with light to make sure it didn't move.

Here you go

How to Set the Ignition Timing on Your Car's Engine - YouTube

Thanks. On one hand I was trying to save a few bucks by not buying a timing light but on the other it would be cool to know that I did it all myself.

[69-Pace]

Brandon - My Uncle was an lifetime GM parts manager and he could tune any engine by sound and a carb by vacuum gauge. While he tried to pass along that talent to me, I was not so successful and several backfires later he suggested I invest in a timing light.

I ran over to Sears on payday and bought the basic unit. Still have it today and it is always the first one used now 30 something years later. However I have also recently purchased a set-back style strobe unit since I was never a good mathematician and advancing and retarding degrees in my head was a problem for me. The new timing light was less then 100 bucks and is available in most big box parts places or Sears. I have also adopted the old school use of a vacuum gauge for tuning my Rochester.

Again just a small price in tools and considerably less then one trip the the classic tune shop in town. All worth the investment and actually these two tool are cheap and reliable as anything made today can be. The satisfaction of I did it myself is priceless.

[withac]

Originally Posted by 69-Pace

Brandon - My Uncle was an lifetime GM parts manager and he could tune any engine by sound and a carb by vacuum gauge. While he tried to pass along that talent to me, I was not so successful and several backfires later he suggested I invest in a timing light.

I ran over to Sears on payday and bought the basic unit. Still have it today and it is always the first one used now 30 something years later. However I have also recently purchased a set-back style strobe unit since I was never a good mathematician and advancing and retarding degrees in my head was a problem for me. The new timing light was less then 100 bucks and is available in most big box parts places or Sears. I have also adopted the old school use of a vacuum gauge for tuning my Rochester.

Again just a small price in tools and considerably less then one trip the the classic tune shop in town. All worth the investment and actually these two tool are cheap and reliable as anything made today can be. The satisfaction of I did it myself is priceless.

Thanks Brian, I think that self satisfaction thing will be the deciding factor. My mechanic is very reasonable and I'm sure would adjust the timing for less than the light but still, making this my ride is really what I want to do. In looking at lights I obviously need an inductive light and I think a tach on it would help tons. As for being able to adjust the advance on the light, from what I've read, a timing tape on the HB will do the job cheaper and is very reliable.