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Mustang Tune-up Guide
This is a collection of different tune-up specifications for both 5.0 and 4.6 S/DOHC engines. Included in this guide are torque specs, fluid capacities, and firing orders. Brothers Performance Tune-up Guide

FRPP Alphabet cam Specs

Advertised duration: 282 intake/282 exhaust
Duration at .050 in. cam lift: 220 intake/220 exhaust
Gross valve lift: .498 in. intake/.498 exhaust
Lobe separation: 110 degrees
Peak horsepower rpm: 5,500
Peak torque rpm: 2,500
Good idle

Advertised duration: 284 intake/284 exhaust
Duration at .050 in. cam lift: 224 intake/224 exhaust
Gross valve lift: .480 in. intake/.480 in. exhaust
Lobe separation: 107 degrees intake/117 degrees exhaust
Peak horsepower rpm: 5,100
Peak torque rpm: 3,300

Advertised duration: 288 intake/288 exhaust Duration @ .050 in. cam lift: 226 intake/226 exhaust
Gross valve lift: .512 intake/.512 exhaust
Lobe separation: 109 degrees intake/119 degrees exhaust
Peak horsepower rpm: 6,000
Peak torque rpm: 2,800
Fair idle

Duration @ .050 in. cam lift: 224 intake/224 exhaust
Gross valve lift: .542 in. intake/.542 in. exhaust
Lobe separation: 107 degrees intake/117 degrees exhaust
Peak horsepower: 6,200 rpm
Peak torque: 3,500
Fair idle

Automotive Calculators
Tire, Gear, Speed Calculator
Automotive Calculators and Converters (Various)

Understanding Cams and Cam Specs

Thump Sticks
Friday, June 20, 2003

Back in the musclecar era, the bigger is better philosophy reigned supreme regarding camshafts. That made for engines that sounded great and could crank some serious top-end power, but were not very drivable on the street and couldn’t idle to save their lives.

But thanks to modern cam technology, you can come pretty darn close to getting the Holy Grail of street bumpsticks—cams that make high rpm power, have good low-end torque and drivability, decent vacuum for power brakes, and have that loping musclecar idle we all love.

Of course, camshaft theory is a very complex subject that can literally take book-length articles to explain. What we’re going to do is give you a little theory and some general guidelines on choosing a good street cam, with emphasis on the hydraulic roller cams most Mustang guys run. With this information, you can call your friendly Summit sales rep or favorite cam grinder and greatly increase your chances of getting the cam you want.

Cam Profile
There are two primary factors that determine a cam’s profile—lift and duration. Lift is the amount a cam lobe actually moves a valve off its seat, and is measured in fractions of an inch. Duration is the amount of time a cam keeps a valve off of its seat, measured in degrees of crank rotation.

Together, lift and duration determine total open valve area—the space available for air and fuel to flow into and out of the combustion chamber. The more valve area open to flow, the more power an engine can (theoretically) make. The trick is to “size” a cam to optimize valvetrain events for your particular engine combination and vehicle usage.

Cam Sizing
Virtually all cam makers use duration to rate cam size. “Big” cams have longer duration, which keeps the valves open longer, increasing midrange and top-end power at the expense of low-end torque. A shorter duration cam does just the opposite. Because it doesn’t keep the valves open as long, a smaller cam boosts low rpm torque production and drivability.

There are two ways to measure duration:
Advertised Duration is the figure you see in the cam ads and hear during those late-night bench races. The problem with advertised duration is cam makers use various methods of measuring it, making it difficult to compare cams from different makers.

Duration at .050 measures duration at .050 inches of valve lift. Since it is used by all cam makers, it’s a much more accurate way to compare cams from different makers.
When you go cam shopping, make sure to compare cams using duration at .050 figures. They may be very close in advertised duration, for example, but make power at different rpms.

Roller vs. Flat Tappet
Now that you have an idea of what lift and duration are, let’s muddy things up with roller versus flat tappet. Roller cams are hardened steel cams that use lifters with a roller, or wheel, that contacts the cam lobes. Flat tappet cams use a lifter with a slightly curved bottom that contacts the lobes.

The roller cam/lifter design has two big advantages. First is the dramatic decrease in friction and wear because the lifter literally rolls over the lobes instead of sliding over them. Second is the ability of the roller lifter to follow more radical cam profiles than a flat tappet lifter. That allows cam designers to make roller cams with more lift without increasing duration. That means a roller can make more midrange and top end power than a flat tappet cam of the same duration, but without sacrificing bottom end power. Small wonder Ford went to rollers way back in 1985!

Lobe Separation
Another factor in a cam’s profile is lobe separation. In basic terms, it is the number of degrees that separate the peak lift points of the cam’s intake and exhaust lobe. Like duration, lobe separation helps determine the rpm range a cam makes its power in. Generally, a cam with wider lobe separation (112-116 degrees) will be biased to making low and midrange power over a wider rpm band. A cam with narrower lobe separation (under 112 degrees) tends to make more top-end power within a narrower rpm band.

For the street, you want a cam with a fairly wide lobe separation for the best power production over a broader rpm range. Go with a cam with narrow lobe separation and you may end up with an engine with a peaky powerband biased to high rpm—not what you want on the street.

Information, Please
When it comes time to actually choose a cam, your sales rep or cam maker will need to know some vehicle and engine parameters to help you get the right cam grind for your vehicle’s particular combination:

Vehicle Weight: The lighter the car, the bigger the cam can be because less low-end torque is necessary to get a lightweight vehicle moving. Heavy vehicles need cams that emphasize low-end power.
Rear Axle Gear Ratio and Tire Size: If you have a bigger (numerically higher) gear ratio, you can use a bigger cam. Lower “economy” gears work better with a mild cam that makes power at low rpms. Tire height is also important because it helps determine your final drive ratio.

Transmission Type: Cams for automatics have to work over a broader rpm range than cams for stick trannies. The powerband should match torque converter stall speed or clutch “dump” rpm.
Engine Size and Compression: A cam’s profile is affected by displacement. Most cam descriptions for small block Fords, for example, are based on 302 cubic inch engines—put one in a 351 Windsor or a stroked five-liter and that cam will act like a milder grind. The bigger the cam duration-wise, the more compression needed to maintain proper cylinder pressure at low rpm.

Airflow: Your cam grinder needs to know the airflow characteristics of your cylinder heads (amount, intake/exhaust ratios, port work, etc.), induction system, and exhaust system to pick a profile that matches engine airflow capabilities.
Power Adders: Superchargers, turbos, and nitrous require special cam profiles to take advantage of the extra power potential. In general, cams made for use with power adders are ground with wider lobe separation to take advantage of the extra cylinder pressure.

Rocker Arm Ratio: Going to a larger rocker arm ratio increases valve lift. The cam should be tailored to work with your specific ratio to avoid slapping valves into pistons or trashing valve springs.

Making a Comparison
OK, let’s play the comparison game. You have a Fox-body Mustang that specs out as follows:
• 3,400 pound vehicle weight, 5-speed, 3.73 rear axle gear
•306 cubic inch small block, 9.5:1 compression with EFI, aluminum heads, shorty headers, and cat-back exhaust

A quick thumb-through of the Ford Racing and Comp Cams catalogs found two popular hydraulic roller street grinds:

Ford Racing X303
(Part Number FMS-M6250X303)
Advertised Duration: 286 degrees intake/ exhaust
Duration at .050: 224 degrees intake/ exhaust
Valve Lift (with 1.6 rocker): .542 inches intake/exhaust
Lobe Separation: 110 degrees
Powerband: 2,500-6,200 rpm

Comp Cams Xtreme Energy OE Roller 35-514-8
(Part Number CCA-355148)
Advertised Duration: 266 degrees intake, 274 degrees exhaust
Duration at .050: 216 degrees intake/224 degrees exhaust
Valve Lift (with 1.6 rocker): .545 inches intake/.555 inches exhaust
Lobe Separation: 112 degrees
Powerband: 1,600-5,600 rpm

If you look at just advertised duration, the Comp cam looks less aggressive than the Ford Racing cam. But when you check duration at .050, you can see both cams are virtually the same duration-wise. This is an example of why you can’t always go by the advertised numbers you see in the magazines.

Where our cams diverge is in lift and lobe separation. The Comp Xtreme Energy grind has far more lift than the Ford Racing cam. Combined with a relatively wide 112 degree lobe separation, it offers good power across the rpm band. The cam also has more lift and duration on the exhaust side to help improve the small block Ford’s poor exhaust breathing. Comp recommends the cam for cars with 3.27-3.73 gears, Mass Air systems, and mild mods like a larger throttle body, headers, and exhaust. Either a five-speed or an AOD automatic with a mild stall converter would be ideal.

The Ford Racing X303 has slightly lower lift figures, but is ground with a narrower 110 degree lobe separation. That makes the cam biased toward high rpm power production; in fact, peak horsepower rpm is a rather lofty 6,500 rpm, almost 1,000 rpm higher than the Xtreme Energy cam. Ford Racing says the X303 should be used with a five-speed manual transmission.

Of course, there is a lot more to camshafts than what we have presented here. But armed with these basics and some help from experts at Summit or the cam companies, you too can get the thumpin street cam you really want.

Fuel Flow

The following chart shows the maximum horsepower potential of the most common sized EFI fuel pumps. This isn't to say that these figures are an example of what you should try to get out of each pump size. These are only examples of the maximum that they are capable of. For all practical purposes, if you are getting near the maximum horsepower your pump can handle, now is definitely the time to step up a size or two.

            12 volts  14 volts  17.5 volts  
88 lph      222hp     267hp    324hp
110 lph     278hp     333hp    405hp
155 lph     391hp     470hp    571hp
190 lph     480hp     576hp    700hp
255 lph     644hp     773hp    939hp
320 lph     808hp     970hp    1178hp

As the previous chart has shown, voltage can greatly affect the flow figures of a pump. To get a better idea of this effect, the following chart shows the effective pump size as related to voltage. One thing to keep in mind is that, as you raise the voltage to a pump, you also reduce its life span. This is why it's best to get the proper size pump as opposed to trying to get squeeze a little extra out of a pump that's just not the right size.

One last thing to consider is that as you raise fuel pressure you also decrease fuel volume. While every pump responds differently to changes such as voltage, fuel pressure has the largest effect on each pump. For this reason, it is very important to buy a pump that will supply the volume of fuel needed at the pressure required for your application. Understand that many OEM pumps drop off dramatically as pressure increases, while other pumps, such as the Vortech T-Rex, do a substantially better job at pressures of 80 psi of more. Unfortunately, even the best pumps will still drop off volume as pressure increases. For example, the very popular Walbro 255 lph intank pump supplies 255 lph at 40 psi, but drops to below 200 lph at 70 psi, and will go below 160 lph at 100 psi. While it would be great to have a single chart to show these affects, it's very tough to do so as each pump responds differently. The best recomendation is to check with the manufacturer or dealer to get the information on their pumps. Only this way can you be sure that you are getting a pump that will safely support the horsepower you plan to make

Ford T-5 Replacing Bearing Part Numbers
Counter Shaft (Cluster):
- Bearings: LM67048
- Front Race: LM67010-BCE
- Rear Race: LM67010

Note: An A6 bearing set includes the LM67048 bearing and LM67010 race.

Input Shaft / Bearing Retainer:
- Bearing: LM48548
- Race: LM48510
- Seal: UCO 159G NOK

Input Shaft / Output Shaft (Cobra Spec and T-5z only):
- Bearing: LM11749
- Race: LM11710

Note: An A1 bearing set includes the LM11749 bearing and LM11710 race.

Output Shaft Rear Bearing:
- Bearing: 25877A
- Race: 25821

4.6 auto to 5-speed tranny swap --- submitted by Banditmp
This was done on my wife's '96 GT, going from a 4R70/W to a T-45.

First thing...

Make a reservation at a reputable mental institution (such as Bryce) so you will know where to be contacted after this swap drives you crazy.

Parts you will need:
Transmission Wiring Harness
Clutch Kit
Pressure Plate to Flywheel Bolts
Pilot Bearing
Flywheel to Crank Bolts
Clutch Fork
Clutch Fork Pivot Ball
Clutch Cable/Quadrant/Firewall Adjuster
Clutch/brake Pedal Assy
Block to Bellhousing Plate
Lower and Upper Shifter Boots
3 Quarts Transmission Fluid
Transmission Mount
Front Slip-Yoke for Driveshaft
3-4 unsuspecting friends

Set aside a full weekend to do the swap...

Remove the auto tranny and all related accessories...mount, cable, torque converter, flexplate, block plate, etc.

Unplug transmission wiring harness from PCM feed behind the right strut tower and pull it out. Plug new harness into PCM feed and drop down behind engine.

Install block plate, flywheel, clutch, and pressure plate onto engine.

Install clutch fork pivot ball and place the TOB on the clutch fork, then install clutch fork.

Remove center console from car, and remove the auto shifter and all associated cables.

Test fit the transmission to determine where you will need to cut the transmission tunnel for the shifter to fit.

Using a die grinder and cut-off wheel, enlarge shifter hole so that the shifter housing will fit with about 1/4" clearance on all four sides. Also test fit the lower shifter boot and mark holes for mounting screws.

Mount transmission, scratch head for 15 or 20 minutes wondering why shifter housing sits so far into passenger compartment. Realize that whoever told you that the bodies were the same for auto and manual lied to you and curse them bitterly.

Bend and trim lower shifter boot until transmission rests properly when crossmember and mount are installed.

Install manual transmission slip yoke onto existing driveshaft.

Install driveshaft and shifter.

Temporarily route clutch cable and remove grommet from firewall.

Attach adjuster to firewall.


Remove the driver's seat for easier access to pedals assembly if you haven't already.

Disconnect all wires from the pedal brackets, disconnect brake booster push rod, and uncouple steering shaft to allow pedals clearance to be removed.

Stand up for 20-30 minutes to keep from getting a nosebleed. (Ask Sendero on this one. )

Install manual pedals assembly and reconnect brake light switch, brake push rod, and steering shaft. Find jumped clutch pedal position switch harness and attach it to clutch pedal position switch. Attach clutch cable to quadrant.

Reinstall center console and driver's seat. Pray devoutly.

Attach clutch cable to clutch fork and secure cable to the frame rail.

You will need to use the current computer until you can get to a dealer to have the computer for the 5-speed programmed for your PATS key. May I suggest buying the M/T computer for the same specs (CA Emission/Federal Emission; etc.) as your Automatic computer.

The swap took us a total of about 24 hours and we didn't run into any major complications.

Speedometer gear chart

1983-1989 T-5 trannys & 96-98 T-45s (Cobra ONLY)

Rearend Ratio;     Speedo gear

3.08                18
3.27                19
3.45                20
3.55                20
3.73                21
4.10                23

1990-1995 T-5 and 1996-1998 t-45 (GT ONLY)
Rearend ratio     Speedo Gear

3.08                 20
3.27                 21
3.55                 23
3.73                 23

Valve adjustment procedure for STUD MOUNT rocker arms by Edgar
Turn the motor slowly until you see the exhaust valve to start opening,
stop, go to the intake valve tight it until there is no lash, then go 1/4
of a turn then lock the poly lock.

Now turn the motor again, now you are going to see that the exhaust
opens completely and then the intake starts to open, now let the
intake valve open completely but as soon you see it to start closing,
stop, now go to your exhaust valve do the same thing as the intake,
then do all of them like that and you are set.
Go to the following thread to see the rest of the discussion.

4.6 Fan switch Mod
Provided by CrazyInBlack

Cooling the 4.6 Mustang with a Fan Switch
Written by Scott 96Cobra
Tuesday, 22 June 1999
Unfortunately our Cobras and GTs DO run hot. There are a few ways to
cool it. If it is a 96 Cobra you can try and get Ford to do the TSB
cooling upgrade which will help, but the downside is that a bigger
radiator (should you ever desire one) will no longer fit. Of course you
could just drop in a Griffin, and be done with it. But should funds
not be available read on.

This mod was told to me by Ryan Hernandez (Purple Haze). I just decided to type it out!

This modification can be done in about 20 minutes and costs next to
nothing. When used, it will lower your operating temperature
approximately 1 to 1.5 letters on the "Normal" gauge. All that is
involved is to wire in a ground for the high-speed fan relay and
switch it so that you can turn it on anytime you want, and leave it
on if so desired! This mod I did last summer, and it WORKS LIKE A

Pull the passenger kick panel and locate the LIGHT-GREEN wire with the purple stripe.
NOTE: There IS a dark-green one on the Cobra.(wrong one - it's a knock sensor wire).
Anyway......once you have located this wire....which will be grouped with a bunch of other wires
running from the EEC up the back of the fire-wall - hard to find, but
its there......(very difficult to get to - Yoga helps).....tap into this
wire (don't cut it in 2, just tap into it) and then solder it back up
and tape it nicely. Then to test it quickly turn your key on to
cycle, and touch the other end of the wire to the ground bolt (also
under the kick panel). You will hear the fan turn on....YEY. Now, you
are NOT done yet! Wire in a 1/2 amp in-line fuse holder with fuse
(safety reasons - no other purpose) and then continue this wire to
a switch and ground the other side of the switch. You are all set! Kenny
Brown sells this package for quite a bit and they give you a switch
that goes in the glove box. You could put it there if you want. I have
a coupe, so I purchased an additional Fog-light switch and
installed it in place of the coin holder. It's nice and neat and accessible.

Grounding this particular wire simply closes the high-speed fan relay and turns on the fan!

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