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Discussion Starter · #1 ·
Hi Guys,

New to this forum and to be honest, I have not tried to search on this subject.

I am replacing a Accel distributor in a 327 sbc. I know little about Chevy. Most of my time is with Fords.

Purchased a Skip White HEI. During installation, I noticed the distributor felt loose even when fully seated. When I compare the two, I noticed the Accel has an extra locating or support boss about 1/3 the way down from the top flange.

Is this something different with the 327 vs other sbcs? Other than OEM, Pertronix "stock look" is the other distributor with this boss. How MSD or DUI fit without the boss?

Thanks,

Scott
 

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There are two bosses. They are on all Chevrolet distributor housings. They are designed to channel the oil flow from the RH oil gallery to the LH oil gallery and to fit the distributor housing in the engine block. I filed a channel in the lower boss directly above the cam and distributor drive gears. That will add pressurized oil flow from the oil gallery to the cam and distributor gears.

I have a Pertronix Stock Look distributor on my 1962 Chevrolet 327/300 and it is the best ignition system I have ever used. However, I have never used a Chevrolet HEI distributor.. When I installed the Pertronix Stock Look distributor, I left the stock coil in place, and left the 6 ohm resistance run wire from the ignition switch and the 12v start wire from the starter terminal as is. I connected the Pertronix red 12v power wire directly to the ignition switch 12v run terminal and the black Pertronix ground to the negative side of the coil. The Pertronix module is powered by 12v, the stock GM coil starts on 12v and runs on 9v, just as before. I use a ACDelco brass terminal cap and painted the Pertronix distributor housing black in order to camouflage it as a stock 1962 distributor. I would have used a Pertronix module in my stock distributor but my 1962 GM distributor was 55 years old and needed to be replaced anyway..

The engine starts instantly and can take the 327 engine RPM high enough to toss a rod.
 

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Hi Guys,

New to this forum and to be honest, I have not tried to search on this subject.

I am replacing a Accel distributor in a 327 sbc. I know little about Chevy. Most of my time is with Fords.

Purchased a Skip White HEI. During installation, I noticed the distributor felt loose even when fully seated. When I compare the two, I noticed the Accel has an extra locating or support boss about 1/3 the way down from the top flange.

Is this something different with the 327 vs other sbcs? Other than OEM, Pertronix "stock look" is the other distributor with this boss. How MSD or DUI fit without the boss?

Thanks,

Scott

There is nothing inside an SBC for the extra flange of the ACCEL distributor to engage. There are only two points of engagement the lower closes the top and bottom of the right (passenger) side tappet oil galley, the upper flange mounts on the intake manifold.


If the distributor feels loose the first thing is to make sure that it has engaged the oil pump drive. The other is to see that there is a gasket seal between the distributor and intake. If the block or heads have been milled that sets the intake lower than production which can cause the oil pump drive engagement to cause the distributor to set high, there are shims sold to solve this problem that go between the intake and the distributor's hold down flange.


Bogie
 

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Discussion Starter · #5 ·
Thanks MouseFink, I'm thinking of going with the stock look for Pertronix also. I have read MSD tech document about grooving the bottom boss. Since I do not know the age or build, I stay with stock for now.

Hi gc408, it may be normal but cannot be good. With any side to side movement, the mate between the distributor and cam would change. With the hype about billet this and precision that, I'm surprised people accept a sloppy
fit.

Thanks for all the comments,

Scott
 

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Discussion Starter · #6 ·
Hi Bogie,

At least in my block, there is a locator hole just below the manifold. I took a picture of it but it's still on my phone.

That why I'm wondering if I have something different.

Going to find casting number or something off the block to look up what it is and how old it is.

Thanks,

Scott
 

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Thanks MouseFink, I'm thinking of going with the stock look for Pertronix also. I have read MSD tech document about grooving the bottom boss. Since I do not know the age or build, I stay with stock for now.

Hi gc408, it may be normal but cannot be good. With any side to side movement, the mate between the distributor and cam would change. With the hype about billet this and precision that, I'm surprised people accept a sloppy
fit.

Thanks for all the comments,

Scott
BTW, A Pertronix Stock Look distributor has a hole in the distributor housing oil channel between the lower bosses. That hole provides pressurized oil to the shaft inside the housing.

That feature provides pressurized oil to the distributor gear and the thrust washers between the gear and the distributor housing. When I received my Pertronix Stock Look distributor, I checked the end play between the gear and housing and it was perfect at .020". Minimum thrust clearance is .015" on GM distributors and adding a .010" thrust washer would make the thrust too tight.
 

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wow did i just educate me self! I was about to tell you no worries BUT i looked at my 283 block and found the original points distriutor and found that the 'third' bushing(appox 1,1/2 down from top flange) is a locating device and inserts into a cast/machined piece of the block [visable in the photo] which dose not exist on later[68+] blocks and the third bushing is not on hei distributors. you can see on the photo that the distributor was off center of the manifold hole which makes the slop necesary.sooo...if you can find after
market three bushing distributor great! but there are millions of sbc running with out it.


.
 

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If you choose to install a Pertronix Stock Look distributor and use a stock ACDelco external resistance coil, you must leave the coil wiring as is and connect the Pertronix module red power wire directly to the back of the ignition switch on the "run" terminal. That is the simple way to install the Pertronix Stock Look distributor if you choose to use a stock ACDelco coil and allow the coil to start on 12v and run on 9v.

If you chooses to use a Pertronix coil which has internal resistance,
you must connect the red Pertronix module 12v supply wire to the positive side of the Pertronix coil. You then must disable and replace the resistance wire from the ignition switch "run" terminal to the coil positive terminal with a 18 AWG stranded copper wire. That will allow the Pertronix module to start and run on 12v and the Pertronix coil with internal resistance will start on 12v and run on 9v due to the Pertronix coil's internal resistor.

A stock ACDelco coil does not have internal resistance and must use a external resistance wire to reduce the running voltage to 9v.

The Pertronix coil has internal resistance and starts on 12v and runs on 9v. The Pertronix magnetic trigger permits faster voltage saturation time (dwell) for the coil in 30 crankshaft degrees. The magnetic trigger eliminates the mechanical points that reduces coil voltage saturation time in 30 degrees as RPM increases.

All ACDelco coils have external resistance. In the start position on the ignition switch, the resistance wire is bypassed and the coil starts on 12v. The ignition switch is returned to the run position and the coil runs on 9v. The exception is the HEI distributor with a intergral coil which starts and runs on 12v. The HEI distributor was introduced in 1971 so low compression engines could ignite the lean fuel air mixtures that was mandated by the 1970 EPA Clean Air Act.
 

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Discussion Starter · #12 ·
gc408, so my block is at least older than 68. At least I have a starting point.

MouseFink, I have no "stock" anything. So with the Pertronix, I would use their coil. Rewiring is not an issue.

Is the Pertronix centrifugal advance system easy to get to? The Accel's weights are below the vacuum advance system. A lot of small parts to remove and lose when making adjustments.

The swap meet was a bust. Not many "quality" vendors and many pulled out early.

Thanks for all the comments,

Scott
 

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gc408, so my block is at least older than 68. At least I have a starting point.

MouseFink, I have no "stock" anything. So with the Pertronix, I would use their coil. Rewiring is not an issue.

Is the Pertronix centrifugal advance system easy to get to? The Accel's weights are below the vacuum advance system. A lot of small parts to remove and lose when making adjustments.

The swap meet was a bust. Not many "quality" vendors and many pulled out early.

Thanks for all the comments,

Scott
Remember, the Pertronix coil has internal resistance to reduce the coil input voltage to 9v. If you use a Pertronix coil, attach the Pertronix module red wire to the coil positive terminal and the Pertronix black wire to the coil negative terminal. You then must disable and bypass the textile covered resistance wire in the wiring harness and place a 18 AWG wire from the ignition switch run terminal to the positive terminal on the Pertronix coil. Transfer the harness start wire to the Pertronix coil positive terminal. That will apply 12v to the positive side of the Pertronix coil when starting and running. Some pre-1968 vehicles have a ballast resistor instead of a resistance wire. A 1962-1964 Chevrolet 409 has a ballast resistor whereas a 1962-up GM vehicles have a stainless steel, textile covered resistance wire from the ignition switch to the ACDelco coil positive terminal.

Pertronix modules will fail in a few miles if 12v is not used to power the module.

The Pertronix Stock Look distributor centrifugal advance mechanism spring tension is adjusted through the vacuum canister port with a Allen wrench. I installed my Pertronix Stock Look distributor as it came out of the box. No centrifugal advance adjustment.

Do not modify or try to adjust the centrifugal advance mechanism. The centrifugal advance adjustment is made through the vacuum canister vacuum port.
 

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Discussion Starter · #14 ·
I can modify the wiring per the instructions with no issues. My only concern is the tach hook up. I first had a lot of problems getting a clean signal. Final I fount instructions for a filter and was able to come up with a setup that worked good.

Adjusting the centrifugal advance through the vacuum canister sounds odd. I do use the vacuum advance limit to control the advance at idle and cruise.

Most of the time, the centrifugal springs have to be changed to change the rate the advance comes in and then the stops are adjusted to control the total centrifugal advance.

With my mustang and a mild 351w, I have the total advance set at 36 with all in by 3,000 rpm. My initial timing is around 12 deg. The vacuum advance is limited to about 10 degrees. I do't notice any pinging at part throttle and medium cruising load. I don't think I have any pinging at WOT.

With the hotrod, I'm thinking I may want all the advance a little sooner due to the car being so light. This was the problem I was chasing when I noticed the damage in the Accel distributor. Now, I need to fix the distributor and see if the timing problem is due to the damage or I still need to bump up the in ital timing.

I'm going to call Pertronix before ordering. May be the stock advance curve with work but I would like to know more about the setup before buying.

Thanks for the comments,

Scott
 

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The Sun tachometer clone on my 1962 Chevrolet with a 4-speed transmission is a one piece replacement from Pep Boys and is made by Bosch. The original Sun tachometer with a transmitter mounted under the hood on the LH fender apron bit the dust years ago. I now use the non-functioning Sun transmitter as a dummy just for looks and the "Sun" tachometer by Bosch is mounted on the steering column with two metal screws and is wired to the stock ACDelco coil negative terminal in the usual manner. I can even get a decal from Ecklers, Show Cars, and from other classic Chevrolet vendors, that appears exactly like the original Sun tachometer face, 5,000 RPM red line for 283 and 327 engines and 6,000 RPM for 409 engines.

A Sun tachometer was factory installed equipment on 1962-1964 Chevrolets that were equipped with a 4-speed manual transmission. A Sun tach was optional on 1962-1964 Chevrolets with a 3-speed or automatic transmission.
 

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Discussion Starter · #16 ·
I ordered a Pertronix.

I spoke with a tech. The mechanical advance is the same as a OEM. So, springs and weights are available.

Thanks for the discussion. It's great to sound ideas of others.

Scott
 

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Discussion Starter · #17 ·
Update on my distributor challenge.

I purchased a Pertronix "stock" look with a igniter III module and a Flame Thrower III coil.

When first installed, I could not get a spark. The voltage at the coil dropped to about 10.5 volts while cranking the engine.

I re-wired the battery and ignition switch. The voltage drop at the coil was about 11 volts while cranking. Still no spark.

Used the battery charger on boost setting showing 15.5 volts at the coil. The engine fired. Ran for 5-10 minutes then started bogging and died.

I could not get the engine to fire again.

I pulled a plug and checked for a spark. The spark was very week looking. Not what I expected with this ignition.

I filed a claim with Pertronix and have heard nothing back. No help of warranty replacement.

Best I can tell now is to not use Pertronix products. Not sure what to expect from Pertronix but after a week without a peep my confidence is running out.

So, I'm back to finding a distributor. This time, I'll find a OEM housing and rebuild it with an electronic trigger.

Scott
 

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Did you disable and remove ( or isolate ) the resistance wire from the starter to the coil positive terminal? The resistance wire (or resistor ) must then be bypassed with a 12v wire. The PerTronix Stock Look distributor with the Ignitor III module must use a PerTronix coil that has a internal resistor. The red wire from the Ignitor III module must be attached to the 12v positive terminal on the PerTronix coil. The textile
covered resistor wire from the ignition switch IGN terminal to the stock coil positive terminal must be disconnected and bypassed with a 12v (18ga) stranded copper wire.

The PerTronix Stock Look distributor with the Ignitor III module must start and run on 12v. Attempting to start the engine on less than 12v will kill the Ignitor III module.

I used a PerTronix Stock Look distributor with a Ignitor I module.. The Ignitor I module is wired with 12v (18 Ga)from the ignition switch IGN terminal, bypassing the textile covered resistance wire, to the Ignitor I module. The resistance wire remains connected to the ACDelco coil positive terminal and the ignition switch IGN terminal

The violet wire from the ignition switch SOL terminal to the starter solenoid "S " terminal and the dark green wire from the starter solenoid " R" terminal to the ACDelco coil positive terminal remains as originally connected by the factory or should be as designed by the factory. When using a Ignitor I module, the ACDelco coil starts the engine on 12v and runs the engine on 9v just as it did with the old points type ignition.

The advantage of the PerTronix Stock Look distributor with Ignitor I module is that a ACDelco coil sees just as much dwell time in degrees at 10,000 RPM as it does at idle speed for maximum voltage saturation and discharge.
 

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Discussion Starter · #20 ·
Yah, I let the saleman suck me in with how well the multi-spark would work with the short headers.

The wiring is all good. Using a pertronix coil with the distributor. Full 12v to everything.

The Pertronix tech said a slight voltage drop while starting would not hurt anything. I tested the power to the coil while cranking and it did drop to about 10.5 volts. I added the battery charger and could maintain above 12 while cranking.

I can understand the electronics being sensitive to sitting powered up but not so much with the voltage. You would have to have a hell of a battery to prevent any voltage sag while starting.

Between the pertronix and hei this seemingly simple replacement turning into a big pile of ......

The small distributor looks better on my engine. But, everyone seems to recommend the pertronix module to convert from points to electronic. Whaaaaaaa.
 
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