Some good info
#1
10-05-2007 | 01:24 PM
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Junior Member
Joined: Mar 2007
Posts: 9
From: United States
<h3>Today’s Gasoline Additives Silent Killers Of GM Engines, Joe Mondello, Engine Builder, June 2001</font></h3>
Over the past several years, I have
answered hundreds of questions about engines: "Why does my engine ping?
detonate? have its valves stick in their guides? have badly worn
exhaust valve seats? Run hot? Make less power than it used to?" </font>
The biggest problem engines face today
is the fuel. It is unstable because of the additives: gasohol, ethanol,
alcohol, etc., which cause fuel to oxygenate. When the fuel sits in the
gas tank for seven to 10 days, it separates and accumulates water, in
turn leaning out the fuel mixture.</font>
Ever since the introduction of unleaded
fuel, we lost tetraethyl lead, which lubricated the upper engine parts,
and we lost octane, which used to eliminate pinging, detonation, upper
cylinder head and engine wear. We now have to go back to square one to
correct the problems.</font>
The octane rating on the pump is not
what goes into the gas tank – it is about one to two octane less. How
can you correct this? In my experience, the use of Sta-bil fuel
stabilizer, about two ounces per five gallons of fuel, and Marvel
Mystery Oil, about four to six ounces per 20 gallons of fuel, is a good
starting point.</font>
The total fuel curve of the engine is
very important and involves everything from the gas tank to the
carburetor, so examine all of the components. Most people have never
checked the condition of the fuel sock in the gas tank to see if it is
clogged with sediment, rust and sludge. A dirty fuel sock is the most
common reason for poor fuel delivery, low fuel pressure and a
lean-running engine.</font>
Steel fuel lines (5/16˝ and 3/8˝) can
get pinched or dented, restricting fuel flow to the carburetor. The
stock fuel pump (which is usually worn out, but even when new is i
nadequate) can only hold 2-1/2 to 4-1/2 psi of pressure. This is hardly
enough when you’re trying to run 4500 to 5000 rpm. I recommend a higher
pressure, higher volume fuel pump for today’s gasoline. Holley,
Edelbrock or Carter mechanical fuel pumps deliver up to 100 gallons per
hour free flow with over 8 psi, but they will need a regulator for
maximum street/strip performance. I prefer 6 to 6.5 psi of steady fuel
pressure.</font>
If your customer is running a Quadrajet,
Edelbrock or Holley carburetor, always remove the paper fuel filter
cartridge from the inlet side of the carburetor and replace it with a
Barry Grant, System One, Moroso or equivalent in-line, free-flowing
fuel filter. If you are running fuel additives, lead substitutes,
octane boosters or carburetor cleaners, the paper cartridges will
deteriorate.</font>
Today’s gasoline is leaning your fuel
mixture between 10 and 14 percent. For owners of motorhomes, this
leaner mixture is really causing more problems than in a car, because
of the 15,000 lbs. being moved, plus the excessive heat being generated
in the engine compartment. The changing of jets and metering rods, both
primary and secondary, is mandatory, especially on Edelbrock and
Quadrajet carburetors. If the Quadrajet has a 72 primary jet and a
.054˝ primary metering rod, you should go up two jet sizes (example: 74
primary jet and .047˝ primary metering rod) enrich the fuel mixture
about five to eight percent. You should continue to enrich the fuel
system until all signs of pinging and detonation are gone.</font>
The easiest way to detect detonation is
to install the Engine Knock Alert from MSD (p/n 8964). This device is
easy to install and easy to use because it flashes a warning light
along with an audible beep. </font>
The MSD adjustable timing control (p/n
8782) works with all point type and electronic distributors. If your
customer uses an MSD box 5, 6, 6-AL or similar in conjunction with one
of the popular electronic distributors, I recommend an MSD-8680
adjustable timing control also be used. </font>
Ignition timing set up is also critical
with today’s gasoline problems. The H.E.I. is the most difficult to do
correctly, especially if you are using it in a performance application.
The stock GM H.E.I. distributor was made for 7.8:1 to 8.5:1 compression
ratio, which used to require very high degrees of timing. The total
timing on a stock 350, 403 or 455 Olds was about 46° to 52° with the
vacuum advance connected. Some Chevy, Ford and Mopar engines in the
’70s also ran very high degrees of timing.</font>
Most distributors that are set between
6° and 10° of initial timing always seem to have more throttle response
for street driveability. </font>
The H.E.I. needs to have the mechanical
advance portion of the distributor reduced. The slot below the movable
counterweights needs to be welded so the travel is shorter. Or, MSD
makes a kit (p/n 8464) that includes counterweight springs and advance
limit bushings which works well if you don’t weld the slot. The slot is
also too long on some point-type trap door distributors and can be
handled in the same manner as the H.E.I. distributor.</font>
The Crane adjustable vacuum advance unit
and vacuum timing limit is highly recommended to slow down the total
vacuum advance (each notch adjustment of the limiter will shorten
vacuum timing by 2°). This should only be used if you can’t reduce
partial throttle-spark knock with the adjustable vacuum advance unit,
movement on the H.E.I and point-type GM distributors. The Crane kit for
HEI (p/n 99600-1) includes springs, timing limiter plate and adjustable
vacuum advance unit. A kit for a GM trap door-type point distributors
is also available (p/n 99601-1).</font>
A good advance curve for Delco point
type and H.E.I. distributors is as follows, but remember, this is only
a starting point – fine tuning adjustments will sometimes be needed.</font>
I recommend the use of MSD timing
controls 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 electronic distributor modules for
Oldsmobile (p/n EM-1181-LSCC) or Chevy (p/n EM-1181-LSC) V8s. The kits
replace the points and condenser, giving more energy and spark through
the coil and to the spark plug. It is a bolt-in item, easily installed.
It retains the stock look of the distributor for show cars and works
with all aftermarket ignition parts.</font>
The stock HEI distributors send a very
weak spark signal to the plug between 2000 and 4000 rpm, so I recommend
an Accel Super Coil (p/n 140005) or a modified HEI dust cover by MSD
(p/n 8401), which allows any good aftermarket coil to be run. These
parts will eliminate poor spark complaints.</font>
A good start for the ignition timing
curve for an HEI or point distributor should be 10°-11° mechanical
advance which is 20° to 22° in the engine, 6° to 10° initial advance
and as little vacuum advance as possible. If you can get away without a
vacuum advance, do it for performance street use. I like the use of a
vacuum advance unit, because it gives far-better driveability under
partial throttle acceleration and cruising speeds.</font>
All Delco HEI and point type
distributors need to be rotor phased. This is critical for street and
racing applications and a free technical bulletin is available on how
to perform it. Set the spark plug gap at .045˝ on the HEI and MSD.
Rotor phasing puts the rotor, cap and module in tune with each other,
giving up to 15 additional horsepower. </font>
Now that the fuel delivery and ignition
timing curves have been taken care of, the next most important thing is
s park plug heat range and spark plug end gap. All point ignitions use
.032˝ end gaps. If you’re working on a 173 Olds 455 with 8.5:1
compression, and you changed it to 10.25:1, 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 plug, because a plug that is too hot
will cause a lean mixture and detonation.</font>
With today’s gasoline, do not run more
than 9.5:1 compression with 92 and 94 octane unleaded fuel. You can run
10:1 compression on the street when using aluminum cylinder heads.</font>
When rebuilding engines, and you expect
them to live, I suggest you follow the tech tips I have recommended.
Here are some others.</font>
Do not use cast iron piston rings.
Today’s fuel doesn’t have any lubrication, so you will experience very
fast cylinder bore wear and short piston ring life. The use of a
premium cast moly ring or a file-fit plasma moly ductile ring is my
recommendation.</font>
Because of the alcohol additives,
today’s gasoline generates more internal engineheat with little
lubrication. You must use more piston-to wall-clearance,
valve-guide-to-valve-stem clearance and piston ring end gap. If your
piston manufacturer wants .002˝ piston-to-wall clearance, I suggest you
use .0025˝. The ring end gap must be increased by .002˝ to .004˝ over
recommended end gaps for your cylinder bore size.</font>
On the valve guides, whether they are
cast iron, solid bronze or bronze guide liners, you must run .0015˝ to
.002˝ intake valve guide clearance and .002˝ to .0025˝ on the exhaus t
valve guide clearance. Less than these clearances will stick the
exhaust valves and kill the engine.</font>
I recommend a light knurl using U.T.P.
(United Tool Processes) knurling equipment for both cast iron and solid
bronze valve guides. I really like K-Line’s valve guide liners with the
interrupted knurl finish. The guide holds oil for better lubrication
and a cooler running valve stem.</font>
The biggest failure area is exhaust
valve seats, and many machine shops destroy a lot of Oldsmobile heads
trying to install small block Chevrolet hardened exhaust valve seats in
Olds heads. The A, B, C, D, E, F and H big block heads, and 1 through 7
and 7A small block heads need hardened exhaust valve seats. The
replacement Chev-rolet exhaust valve seat is 7/32˝ (.21875˝) to 1/4˝
(.250˝) thick and will usually hit the water jacket in an Oldsmobile
cylinder head.</font>
We make two special size Oldsmobile
exhaust valve seats which are both 3/16˝ (.1875˝) thick. The seats are
available in 1.750˝ (p/n 1453) and 1.625˝ (p/n 2453) O.D., so they will
not hit water, and are made of powder metal alloy which lubricates
itself for long exhaust valve and seat life.</font>
Good distributor blueprinting is one of
the most difficult services to find. I have found through extensive
testing that Pro-Blend 40-Below radiator coolant additive and Torco
motor oil with MPZ will lower your engine and oil temperatures
dramatically.</font>
Remember that detonation and pinging
aren’t always audible, but are the signs of a silent killer. If you
follow these tips and do to your customers’ engines and tune up as I
recommend, the engines will live a longer, happier life.</font>
For more details about recommended part
numbers or availability of parts noted in this column, or for a free
technical bulletin on rotor phasing, contact Mondello Technical School
at [img]chrome://skype_ff_toolbar_win/content/cb_transparent_l.gif[/img]</span>[img]chrome://skype_ff_toolbar_win/content/famfamfam/us.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/arrow.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img]</span></span>[img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img]805-237-9185</span>[img]chrome://skype_ff_toolbar_win/content/cb_transparent_r.gif[/img]</span></span></span>; fax 805-237-9154; or email jmondello@engine-builder.com.</font>
Over the past several years, I have
answered hundreds of questions about engines: "Why does my engine ping?
detonate? have its valves stick in their guides? have badly worn
exhaust valve seats? Run hot? Make less power than it used to?" </font>
The biggest problem engines face today
is the fuel. It is unstable because of the additives: gasohol, ethanol,
alcohol, etc., which cause fuel to oxygenate. When the fuel sits in the
gas tank for seven to 10 days, it separates and accumulates water, in
turn leaning out the fuel mixture.</font>
Ever since the introduction of unleaded
fuel, we lost tetraethyl lead, which lubricated the upper engine parts,
and we lost octane, which used to eliminate pinging, detonation, upper
cylinder head and engine wear. We now have to go back to square one to
correct the problems.</font>
The octane rating on the pump is not
what goes into the gas tank – it is about one to two octane less. How
can you correct this? In my experience, the use of Sta-bil fuel
stabilizer, about two ounces per five gallons of fuel, and Marvel
Mystery Oil, about four to six ounces per 20 gallons of fuel, is a good
starting point.</font>
The total fuel curve of the engine is
very important and involves everything from the gas tank to the
carburetor, so examine all of the components. Most people have never
checked the condition of the fuel sock in the gas tank to see if it is
clogged with sediment, rust and sludge. A dirty fuel sock is the most
common reason for poor fuel delivery, low fuel pressure and a
lean-running engine.</font>
Steel fuel lines (5/16˝ and 3/8˝) can
get pinched or dented, restricting fuel flow to the carburetor. The
stock fuel pump (which is usually worn out, but even when new is i
nadequate) can only hold 2-1/2 to 4-1/2 psi of pressure. This is hardly
enough when you’re trying to run 4500 to 5000 rpm. I recommend a higher
pressure, higher volume fuel pump for today’s gasoline. Holley,
Edelbrock or Carter mechanical fuel pumps deliver up to 100 gallons per
hour free flow with over 8 psi, but they will need a regulator for
maximum street/strip performance. I prefer 6 to 6.5 psi of steady fuel
pressure.</font>
If your customer is running a Quadrajet,
Edelbrock or Holley carburetor, always remove the paper fuel filter
cartridge from the inlet side of the carburetor and replace it with a
Barry Grant, System One, Moroso or equivalent in-line, free-flowing
fuel filter. If you are running fuel additives, lead substitutes,
octane boosters or carburetor cleaners, the paper cartridges will
deteriorate.</font>
Today’s gasoline is leaning your fuel
mixture between 10 and 14 percent. For owners of motorhomes, this
leaner mixture is really causing more problems than in a car, because
of the 15,000 lbs. being moved, plus the excessive heat being generated
in the engine compartment. The changing of jets and metering rods, both
primary and secondary, is mandatory, especially on Edelbrock and
Quadrajet carburetors. If the Quadrajet has a 72 primary jet and a
.054˝ primary metering rod, you should go up two jet sizes (example: 74
primary jet and .047˝ primary metering rod) enrich the fuel mixture
about five to eight percent. You should continue to enrich the fuel
system until all signs of pinging and detonation are gone.</font>
The easiest way to detect detonation is
to install the Engine Knock Alert from MSD (p/n 8964). This device is
easy to install and easy to use because it flashes a warning light
along with an audible beep. </font>
The MSD adjustable timing control (p/n
8782) works with all point type and electronic distributors. If your
customer uses an MSD box 5, 6, 6-AL or similar in conjunction with one
of the popular electronic distributors, I recommend an MSD-8680
adjustable timing control also be used. </font>
Ignition timing set up is also critical
with today’s gasoline problems. The H.E.I. is the most difficult to do
correctly, especially if you are using it in a performance application.
The stock GM H.E.I. distributor was made for 7.8:1 to 8.5:1 compression
ratio, which used to require very high degrees of timing. The total
timing on a stock 350, 403 or 455 Olds was about 46° to 52° with the
vacuum advance connected. Some Chevy, Ford and Mopar engines in the
’70s also ran very high degrees of timing.</font>
Most distributors that are set between
6° and 10° of initial timing always seem to have more throttle response
for street driveability. </font>
The H.E.I. needs to have the mechanical
advance portion of the distributor reduced. The slot below the movable
counterweights needs to be welded so the travel is shorter. Or, MSD
makes a kit (p/n 8464) that includes counterweight springs and advance
limit bushings which works well if you don’t weld the slot. The slot is
also too long on some point-type trap door distributors and can be
handled in the same manner as the H.E.I. distributor.</font>
The Crane adjustable vacuum advance unit
and vacuum timing limit is highly recommended to slow down the total
vacuum advance (each notch adjustment of the limiter will shorten
vacuum timing by 2°). This should only be used if you can’t reduce
partial throttle-spark knock with the adjustable vacuum advance unit,
movement on the H.E.I and point-type GM distributors. The Crane kit for
HEI (p/n 99600-1) includes springs, timing limiter plate and adjustable
vacuum advance unit. A kit for a GM trap door-type point distributors
is also available (p/n 99601-1).</font>
A good advance curve for Delco point
type and H.E.I. distributors is as follows, but remember, this is only
a starting point – fine tuning adjustments will sometimes be needed.</font>
I recommend the use of MSD timing
controls 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 electronic distributor modules for
Oldsmobile (p/n EM-1181-LSCC) or Chevy (p/n EM-1181-LSC) V8s. The kits
replace the points and condenser, giving more energy and spark through
the coil and to the spark plug. It is a bolt-in item, easily installed.
It retains the stock look of the distributor for show cars and works
with all aftermarket ignition parts.</font>
The stock HEI distributors send a very
weak spark signal to the plug between 2000 and 4000 rpm, so I recommend
an Accel Super Coil (p/n 140005) or a modified HEI dust cover by MSD
(p/n 8401), which allows any good aftermarket coil to be run. These
parts will eliminate poor spark complaints.</font>
A good start for the ignition timing
curve for an HEI or point distributor should be 10°-11° mechanical
advance which is 20° to 22° in the engine, 6° to 10° initial advance
and as little vacuum advance as possible. If you can get away without a
vacuum advance, do it for performance street use. I like the use of a
vacuum advance unit, because it gives far-better driveability under
partial throttle acceleration and cruising speeds.</font>
All Delco HEI and point type
distributors need to be rotor phased. This is critical for street and
racing applications and a free technical bulletin is available on how
to perform it. Set the spark plug gap at .045˝ on the HEI and MSD.
Rotor phasing puts the rotor, cap and module in tune with each other,
giving up to 15 additional horsepower. </font>
Now that the fuel delivery and ignition
timing curves have been taken care of, the next most important thing is
s park plug heat range and spark plug end gap. All point ignitions use
.032˝ end gaps. If you’re working on a 173 Olds 455 with 8.5:1
compression, and you changed it to 10.25:1, 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 plug, because a plug that is too hot
will cause a lean mixture and detonation.</font>
With today’s gasoline, do not run more
than 9.5:1 compression with 92 and 94 octane unleaded fuel. You can run
10:1 compression on the street when using aluminum cylinder heads.</font>
When rebuilding engines, and you expect
them to live, I suggest you follow the tech tips I have recommended.
Here are some others.</font>
Do not use cast iron piston rings.
Today’s fuel doesn’t have any lubrication, so you will experience very
fast cylinder bore wear and short piston ring life. The use of a
premium cast moly ring or a file-fit plasma moly ductile ring is my
recommendation.</font>
Because of the alcohol additives,
today’s gasoline generates more internal engineheat with little
lubrication. You must use more piston-to wall-clearance,
valve-guide-to-valve-stem clearance and piston ring end gap. If your
piston manufacturer wants .002˝ piston-to-wall clearance, I suggest you
use .0025˝. The ring end gap must be increased by .002˝ to .004˝ over
recommended end gaps for your cylinder bore size.</font>
On the valve guides, whether they are
cast iron, solid bronze or bronze guide liners, you must run .0015˝ to
.002˝ intake valve guide clearance and .002˝ to .0025˝ on the exhaus t
valve guide clearance. Less than these clearances will stick the
exhaust valves and kill the engine.</font>
I recommend a light knurl using U.T.P.
(United Tool Processes) knurling equipment for both cast iron and solid
bronze valve guides. I really like K-Line’s valve guide liners with the
interrupted knurl finish. The guide holds oil for better lubrication
and a cooler running valve stem.</font>
The biggest failure area is exhaust
valve seats, and many machine shops destroy a lot of Oldsmobile heads
trying to install small block Chevrolet hardened exhaust valve seats in
Olds heads. The A, B, C, D, E, F and H big block heads, and 1 through 7
and 7A small block heads need hardened exhaust valve seats. The
replacement Chev-rolet exhaust valve seat is 7/32˝ (.21875˝) to 1/4˝
(.250˝) thick and will usually hit the water jacket in an Oldsmobile
cylinder head.</font>
We make two special size Oldsmobile
exhaust valve seats which are both 3/16˝ (.1875˝) thick. The seats are
available in 1.750˝ (p/n 1453) and 1.625˝ (p/n 2453) O.D., so they will
not hit water, and are made of powder metal alloy which lubricates
itself for long exhaust valve and seat life.</font>
Good distributor blueprinting is one of
the most difficult services to find. I have found through extensive
testing that Pro-Blend 40-Below radiator coolant additive and Torco
motor oil with MPZ will lower your engine and oil temperatures
dramatically.</font>
Remember that detonation and pinging
aren’t always audible, but are the signs of a silent killer. If you
follow these tips and do to your customers’ engines and tune up as I
recommend, the engines will live a longer, happier life.</font>
For more details about recommended part
numbers or availability of parts noted in this column, or for a free
technical bulletin on rotor phasing, contact Mondello Technical School
at [img]chrome://skype_ff_toolbar_win/content/cb_transparent_l.gif[/img]</span>[img]chrome://skype_ff_toolbar_win/content/famfamfam/us.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/arrow.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img]</span></span>[img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img][img]chrome://skype_ff_toolbar_win/content/space.gif[/img]805-237-9185</span>[img]chrome://skype_ff_toolbar_win/content/cb_transparent_r.gif[/img]</span></span></span>; fax 805-237-9154; or email jmondello@engine-builder.com.</font>
#2
10-05-2007 | 02:30 PM
Super Moderator
Joined: Aug 2005
Posts: 282
From: United States
Good,but datedinfo. Andit wasn't all true even when he wrote it(especially about HEI usage and Accell parts).
Joe used to be the only guy out there carrying the torch for Olds performance. There are a lot of really goodshops out there now that are surpassing him in products, priceand (more importantly) customer service. (Lesson #1: Don't let your weasel son-in-law take over your business!)
C.J.Edited by: texasred
#4
10-05-2007 | 05:44 PM
Super Moderator
Joined: Aug 2005
Posts: 282
From: United States
http://www.btrperformance.com/
http://www.dickmillerracing.com/
http://www.fcrparts.com/
http://www.robbmcperformance.com/
http://www.rocketracingperformance.com/
Just to name a few. And if you are looking for a GREAT book on Olds buildups, let me throw out a hearty endorsement for Bob Gerometta' Oldsmobile Engine Modification and Tuning Guide. http://stores.ebay.com/Wild-About-Cars-and-Car-StuffBest $20 I have spent in a looooooong time!
C.J.
#7
10-06-2007 | 09:11 PM
Super Moderator
Joined: Aug 2005
Posts: 282
From: United States
Not showing off, ilike. Just helping when I can.
Showing off is empty post whoring, sniping at n00bs and being generally snarky. Not that I've never done that, but I'd like to think (for the most part) that my posts have some meatin them.
C.J.
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