The easiest way to detect detonation (pinging) is to install the Engine
K~ock Alert from MSD~(part #a964). The Knock AI'ert is. easy to install and
is especially easy to see for the hard 6f hearing individual. The Knock
Alert flashes a warning light and an audible beep. The Knock Alert and
adjustable timing control from MSD is a must for GMC Motor Home owners, The
use of an adjustable timing control from MSD is recommended for all cars,
stock, performance, motor homes, etc., so you can fine tune your engines for
an ever changing environment. The MSD Adjustable Timing Control. (part
#8782) will work with all pint type and Electronic distributors, Accel , Mal
lQry, Mondel lo, Pertronix, etc, plus GM H.E.I. distributors. If you are
using a MSD box 5, 6, 6-AL, etc., in~conjunction with the above
distributors, than I recommend you use a MSD-8780 Adjustable Timing Control.
Your ignition timing and the way you set it up is most important with todays
gasoline. The H.E.1. is the most difficult, especially if you are using it
in a performance application. The stock GM H.E.I. distributor was made for
7.8'to 1 to 8.5 to 1 compression ratio which use to require very high
degrees of timing. The total timing on a stock 350 -403 -455 was about 46
~t6~2 degrees with the vacuum advance connected. Most distributors that are
set between 6 and 10 degrees of initial timing always seem to have more
throttle response for street driveability. The H.E.I. needs to have the
mechanical advance portion of the distributor reduced. The slot below the
movable counter weights needs to be welded up so the travel is shorter. MSD
makes a kit that includes counterweight springs and advance limit bushings
(part #8464) which, works well if you don't weld up the counterweight
mechanical advance slot. This slot is also too long on some point type trap
door distributors and can be handled in the same manor as the H.E.I.
distributor. The Crane adjustable vacuum advance unit and vacuum timing
limit is highly recommended. To slow down your total vacuum advance (each
notch adjustment of the limiter will shorten vacuum timing by 2 degrees.
This should only be used if you can't reduce part throttle spark knock with
the adjustable vacuum advance unit.), movement on the H.E.I. & Point Type GM
distributors. The Crane kit for H.E.I. includes springs, timing limiter
plate and adjustable vacuum advance unit (part #99600-1). The same kit for a
GM Trap door point type distributor is (part #99601-1). A good advance
curve for Delco point type and H.E.I. distributors is as follows. Remember
this is only a starting point and fine tuning adjustments will- sometimes be
needed. The use of the MSD timing controls are going to be your best bet
after you have reached a happy medium on initial mechanical and vacuum
advance settings. On all point type Delco Trap door distributors, I
recommend our EM-1181 Electronic Distributor Module. The kit replaces your
points an~ condenser, giving you more energy and spark through your coil and
to the spark plugs. This kit is a bolt in item and can be done in your
garage at hbme. It~retains the stock look of thedistributor for show cars.
The kit works with a~l aftermarket' ignition parts, MSD, Accel, etc. The
stock U.E.I. distributors have a very weak spark~signal to the spark plug
between 2000 & 4000 RPM so I recommend an Accel super Coil (part~#l4OOOS) or
a modified H.E.I. dust cover by MSD (part #8401) which allows you to run any
good after market MSD, Accel, Mallory or Mondello 8302 Coil. The MSD High
Energy Module (part #8364) and MSD Coil (part #8225) are for the H.E.I.
distributor. These MSD parts will eliminate the poor spark between 2000 and
4000 RPM. The curve for an H.E.1. or point distributor should be 10 or 11
degrees, mechanical advance which is 20 -22 degrees in the engine, 6 to 10
degrees initial advance and as little vacuum advance as possible, is a good
start. If you can get away without a vacuum advance, do it for performance
street use. I do like the use of a vacuum advance unit, far better
driveability under part throttle acceleration and cruising speeds. All
Delco, H.E.I. and point type distributors need to'be rotor-phased.
Rotor-phasing puts the rotor, cap and module in tune with each other giving
you up to 15 more horse power. We have a-free 'Tech Bulletin (#104) on how
to perform rotor-phasing. This is very critical for street and racing use.
Now we have taken care of the fuel delivery curve and ignition timing curve
of the engine. The next most important thing is spark plug heat range and
spark plug end gap. All H.E.I. and MSD ignition systems use .045 end gap.
All point type, Pertronix, Mondello, etc., use .032 end gap. If you have a
1973 Olds 455, that had 8.5 to 1 compression, and you changed to 10.25 to 1,
do not run the AC 46-S spark plug that came with the car in 1973 because
they are too hot. You should be using an AC 44-S spark plug. A spark plug
that is too hot will cause a lean mixture and detonation. W~ith todays
gasoline, do not run more than 9.5 to 1 compression with 92 to 94 octane
unleaded fuel. If you are going to use the new Edelbrock Aluminum head,
when it is available, you can run 10 to 1 compression. The gasoline we buy
today is some of the worst I have ever used.
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
K~ock Alert from MSD~(part #a964). The Knock AI'ert is. easy to install and
is especially easy to see for the hard 6f hearing individual. The Knock
Alert flashes a warning light and an audible beep. The Knock Alert and
adjustable timing control from MSD is a must for GMC Motor Home owners, The
use of an adjustable timing control from MSD is recommended for all cars,
stock, performance, motor homes, etc., so you can fine tune your engines for
an ever changing environment. The MSD Adjustable Timing Control. (part
#8782) will work with all pint type and Electronic distributors, Accel , Mal
lQry, Mondel lo, Pertronix, etc, plus GM H.E.I. distributors. If you are
using a MSD box 5, 6, 6-AL, etc., in~conjunction with the above
distributors, than I recommend you use a MSD-8780 Adjustable Timing Control.
Your ignition timing and the way you set it up is most important with todays
gasoline. The H.E.1. is the most difficult, especially if you are using it
in a performance application. The stock GM H.E.I. distributor was made for
7.8'to 1 to 8.5 to 1 compression ratio which use to require very high
degrees of timing. The total timing on a stock 350 -403 -455 was about 46
~t6~2 degrees with the vacuum advance connected. Most distributors that are
set between 6 and 10 degrees of initial timing always seem to have more
throttle response for street driveability. The H.E.I. needs to have the
mechanical advance portion of the distributor reduced. The slot below the
movable counter weights needs to be welded up so the travel is shorter. MSD
makes a kit that includes counterweight springs and advance limit bushings
(part #8464) which, works well if you don't weld up the counterweight
mechanical advance slot. This slot is also too long on some point type trap
door distributors and can be handled in the same manor as the H.E.I.
distributor. The Crane adjustable vacuum advance unit and vacuum timing
limit is highly recommended. To slow down your total vacuum advance (each
notch adjustment of the limiter will shorten vacuum timing by 2 degrees.
This should only be used if you can't reduce part throttle spark knock with
the adjustable vacuum advance unit.), movement on the H.E.I. & Point Type GM
distributors. The Crane kit for H.E.I. includes springs, timing limiter
plate and adjustable vacuum advance unit (part #99600-1). The same kit for a
GM Trap door point type distributor is (part #99601-1). A good advance
curve for Delco point type and H.E.I. distributors is as follows. Remember
this is only a starting point and fine tuning adjustments will- sometimes be
needed. The use of the MSD timing controls are going to be your best bet
after you have reached a happy medium on initial mechanical and vacuum
advance settings. On all point type Delco Trap door distributors, I
recommend our EM-1181 Electronic Distributor Module. The kit replaces your
points an~ condenser, giving you more energy and spark through your coil and
to the spark plugs. This kit is a bolt in item and can be done in your
garage at hbme. It~retains the stock look of thedistributor for show cars.
The kit works with a~l aftermarket' ignition parts, MSD, Accel, etc. The
stock U.E.I. distributors have a very weak spark~signal to the spark plug
between 2000 & 4000 RPM so I recommend an Accel super Coil (part~#l4OOOS) or
a modified H.E.I. dust cover by MSD (part #8401) which allows you to run any
good after market MSD, Accel, Mallory or Mondello 8302 Coil. The MSD High
Energy Module (part #8364) and MSD Coil (part #8225) are for the H.E.I.
distributor. These MSD parts will eliminate the poor spark between 2000 and
4000 RPM. The curve for an H.E.1. or point distributor should be 10 or 11
degrees, mechanical advance which is 20 -22 degrees in the engine, 6 to 10
degrees initial advance and as little vacuum advance as possible, is a good
start. If you can get away without a vacuum advance, do it for performance
street use. I do like the use of a vacuum advance unit, far better
driveability under part throttle acceleration and cruising speeds. All
Delco, H.E.I. and point type distributors need to'be rotor-phased.
Rotor-phasing puts the rotor, cap and module in tune with each other giving
you up to 15 more horse power. We have a-free 'Tech Bulletin (#104) on how
to perform rotor-phasing. This is very critical for street and racing use.
Now we have taken care of the fuel delivery curve and ignition timing curve
of the engine. The next most important thing is spark plug heat range and
spark plug end gap. All H.E.I. and MSD ignition systems use .045 end gap.
All point type, Pertronix, Mondello, etc., use .032 end gap. If you have a
1973 Olds 455, that had 8.5 to 1 compression, and you changed to 10.25 to 1,
do not run the AC 46-S spark plug that came with the car in 1973 because
they are too hot. You should be using an AC 44-S spark plug. A spark plug
that is too hot will cause a lean mixture and detonation. W~ith todays
gasoline, do not run more than 9.5 to 1 compression with 92 to 94 octane
unleaded fuel. If you are going to use the new Edelbrock Aluminum head,
when it is available, you can run 10 to 1 compression. The gasoline we buy
today is some of the worst I have ever used.
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
