Does anyone have a picture of the weights and spring configuration on a hei distributor. I think I might have installed the center plate wrong. So if you got a picture could ya share it.

Thanks

 

It's not HEI, but it might help:

 

Some distributors they switch around which way the weights are oriented (going with or against diration of rotation). You'll want to look at an actual HEI to be sure.

That being said, first thing you do is install the weights with the stamped number UP (most HEI weights are stamped 106). If they are used pieces the wear pattern will be DOWN where they rub against the plastic rub "pucks" on top of the advance plate.

Now that you have the weights in correctly you want to make sure that the TAILS of the weights (the pointy part) rides against the SMOOTH CURVED SIDE of the centerplate. The stamped number will be pointing UP. If it's not, flip it over and it will be oriented correctly.

 

1
1. Remove the air cleaner (if necessary) and cover the carburetor
and around the base of the distributor to protect
against the dropping of small parts into the engine (FIG. 1).
2. Remove the tachometer (if any), battery, and distributor
connections from the distributor cap (FIG. 2)
3. Remove the distributor cap (FIG. 3). (NOTE: Some engines
may require the disconnecting of spark plug and/or coil
wires. If so, mark them accordingly.)
4. Remove the rotor and check the condition of all parts, and
replace as needed (FIG. 4).
5. Remove the centrifugal advance springs (FIG. 5) and
inspect the weights and pins at the pivot points (FIG. 5A).
Replace the weights and pins if they show rust or extreme
wear. Stock GM weights are recommended. (NOTE: Be
sure to lubricate pivot points when installing new parts.)
6. Install a blue (heavy) and silver (medium) spring in the distributor
in place of the stock springs (FIG. 6). This combination
will be ideal for most applications, and is recommended
as a starting point.
Automotive ignition timing advance consists of three components:
Initial timing, centrifugal advance, and vacuum advance.
INITIAL TIMING - Is the point where the distributor is set in the
engine prior to start up. This timing can be advanced or retarded
by moving the distributor.
CENTRIFUGAL ADVANCE - Is a function of the engine RPM, and
will increase as the engine's RPM increases. The centrifugal
advance is controlled by the weights and springs inside the distributor.
VACUUM ADVANCE - Is a function of the engine manifold vacuum.
As the engine vacuum decreases, the vacuum advance will
decrease. At full throttle, engine vacuum is zero and vacuum
advance is zero.
TOTAL ADVANCE - Is the total of initial advance, centrifugal
advance, and vacuum advance added together.
The following instructions are designed to allow you to re-curve
your distributor in the vehicle. This procedure may also be done on
a distributor machine, if a predetermined curve is desired.
210G2 5/00
Installation and Operation Instructions
Adjustable Vacuum
Advance Kit
For GM H.E.I. Distributors
CRANE CAMS, INC. 530 Fentress Blvd., Daytona Beach, FL 32114
Tech Line: (386) 258-6174 www.cranecams.com Fax: (386) 258-6167
For more information, see www.cranecams.com
FIG. 1
FIG. 4
FIG. 5
FIG. 5A
FIG. 2
FIG. 3
Legal only for pre-1966 California and pre-1968 Federally certified passenger cars.
2
7. Remove the stock vacuum advance unit (FIG. 7), and using
the same screws, install the new Adjustable Vacuum
Advance Unit (FIG 7A). The Adjustable Vacuum Advance
Unit will allow you to tailor the vacuum advance curve to
suit your application.
8. Using the 3/32" allen wrench (included with the kit), insert
the wrench through the vacuum port and adjust to maximum
clockwise position (FIG. 8A). Leave the vacuum hose
disconnected and plugged. Replace distributor rotor cap,
and all wires previously removed (FIG. 8B-8C).
9. With the vacuum hose disconnected and plugged, set the
initial timing at 2° advance from factory specifications and
make full throttle acceleration runs, listening for audible
spark knock. If spark knock occurs, then retard the initial
timing 2° and check for spark knock by making another full
throttle acceleration run. If spark knock stops, you have the
ideal centrifugal advance curve. If spark knock continues,
then select the next heavier spring combination and repeat
the test procedure. If no spark knock occurs on the first
test, select the next lightest combination and repeat the
test.
10. Connect the adjustable vacuum advance unit to the manifold
vacuum source.
11. Test-drive the vehicle in the city and on the highway while
listening for audible spark knock under heavy load and part
throttle. If spark knock occurs under part throttle conditions,
a change in the vacuum advance curve is needed.
This adjustment is made by inserting the 3/32" allen wrench
into the vacuum advance unit and turning the adjuster
counterclockwise two turns at a time, testing the vehicle
after each change, until part throttle spark knock is eliminated.
The curve you have achieved is designed to give you the best
economy and performance.
SPRING COMBINATIONS
START ADVANCE FULL ADVANCE
SPRING COMBINATION ENGINE RPM ENGINE RPM
Blue/Blue . . . . . . . . . . . . . . . . . .800 . . . . . . . . . . . . . . . . .3200
Blue/Silver . . . . . . . . . . . . . . . . .800 . . . . . . . . . . . . . . . . .2800
Blue/Yellow . . . . . . . . . . . . . . . . .800 . . . . . . . . . . . . . . . . .2600
Silver/Silver . . . . . . . . . . . . . . . .600 . . . . . . . . . . . . . . . . .2200
Silver/Yellow . . . . . . . . . . . . . . . .500 . . . . . . . . . . . . . . . . .1800
Yellow/Yellow . . . . . . . . . . . . . . .500 . . . . . . . . . . . . . . . . .1600
BLUE - HEAVY SILVER - MEDIUM YELLOW-LIGHT
In general, GM cars and trucks originally equipped with HEI distributors
will be able to use a total advance of 45° to 55°. Some
factors may limit the amount of total ignition timing your vehicle can
use. These factors are increased compression, declining octane
rating of gasoline, certain intake manifolds that will not tolerate
increased ignition timing, lock-up torque converters, extremely
heavy loads, and lean fuel mixture.
NOTE: The GM HEI distributor has a centrifugal advance of 20
crank degrees with stock weights. Using advance weights other
than stock may change the centrifugal advance curve and total
advance.
210G2 5/00
FIG. 6
FIG. 7
FIG. 7A
FIG. 8B
FIG. 8C
FIG. 8A

 

Sorry about the photos but they really help cant figure out how to send them. I hope this helps some people who wanted to know how to recurve like I did.

Ed