Foreword
Before diving into the horsepower charts, a few items need to be clarified first. This is for 460 Ford motors with 4.36-4.44-inch bores and 3.85-inch stroke. These charts are for new members, either just getting into engines or coming from a different motor and wanting to know the particulars about building a 460, and for seasoned Ford 460 users wanting to know how to attain a certain horsepower from their combo. It is not a pump gas only list. It is designed to give the best overall performance for a given hp range.
A brief note on detonation. If you build a motor to the ragged edge of pump gas, and it detonates, you lose horsepower and you will harm the motor. It is better to sacrifice a little power (4% per point) and use less compression. If you are determined to use high compression, use race gas. It is cheaper in the long run than to harm your engine with detonation. Octane requirements have been noted in the builds.
Basic Suggestions
The intake system
It can not be stressed enough how important the carburetor is to the build. It will determine how the vehicle runs, not only at WOT, but at all the other speeds as well. A box stock Holley Double Pumper (DP) is set from the factory rich. People often complain of poor gas mileage from the DPs because they use them on their street vehicles straight out of the box. The idle and cruising circuits are very rich, and it takes a professional carburetor tuner to get the DPs set-up properly for the street. Not only for street use, but racing use also needs the carburetor to be set-up properly. The money spent on a professional carburetor tuner pays for itself, especially with the price of gas nowadays.
Cylinder heads
This is the area where you will have, or have not, the horsepower you’re seeking.
A good thread for information on the cylinder heads used in these build-ups and other heads can be found here:
http://460ford.com/viewtopic.php?t=18321
At every horsepower level, the cylinder head should be purchased from a professional cylinder head shop/porter. There is power to be found in doing a correct valve job even at the lowest of hp levels.
Furthermore, the TFS heads and P51 are mass produced items. A professional can get them "dialed-in". Do not think because you paid X amount of dollars that the head is perfect. Sometimes, not always, they need a little touching up for them to flow like they should out of the box, a lap job for the valve seal, etc.
Shortblock info
A word on basic machining. The basic part recommendations in each horsepower level increases as rpm rises. It is rpm, and not horsepower that requires the better parts. The time spent at the higher rpms also affects part selection. When in doubt, it never hurts to upgrade parts. The parts suggested at each build level will be able handle the rpm with good machining.
Good machining starts with making sure all parts are sound. All steel parts should be magnaflux crack tested, and all aluminum parts with zyglo. Every part should be checked, even new parts, to make sure they have correct measurements. If you find measurements to be off, have them corrected. Even though machining in it itself does not add a significant amount of power between the best job and a poor job, the life of the engine can be affected greatly. The higher the rpm, the more critical and costly the machining becomes, due to the machinist having to mock up multiple times, setting up his equipment to get the machining “spot on”, and checking and rechecking engine measurements. Be aware also that aftermarket “race” components often require “fitting” to make them work. They typically do not just bolt-on.
On 400 to 550 hp builds, it is prudent to find a good machinist/engine builder. Past the 550 hp mark, it is best not only to find a good machinist/engine builder, but one who is familiar with building 460s. There are minor things that can make or break the combo beyond 550 hp.
The stock crank, 2-bolt mains, and factory bolts are good to the 675-700 horsepower build which after the block should be 4-bolted. It is rpm again, for the need to 4-bolt. Anytime rpm exceeds 7500 rpm, aluminum rods should be considered, as cap walk starts to show up after that rpm with steel rods.
Paul Kane’s website on oiling mods:
http://www.highflowdynamics.com/
Quench
There is more power than just raising the compression by using quench. Here is a quote from Scott Johnson and Paul Kane on the subject of the importance of quench and engine performance. In all the engine builds, this is factored in.
Exhaust system
It is important to use a free flowing muffler in all the builds. Flow- Masters do not flow enough. Any muffler were you can pick it up and look thru it, without barbs or such protruding into the airflow will be a good flowing one. If noise is a concern, then a termination box should be built and then mufflers. You are striving for no back pressure.
Adding a stroker kit
Some have asked about a horsepower chart for stroker kits. Some of the most common are:
4.39 bore x 4.15 stroke = 502 cubic inches
4.39 bore x 4.3 stroke = 520 cubic inches
4.39 bore x 4.5 stroke = 545 cubic inches
By adding a stroker crankshaft, the following occurs:
1) For every 50 cubic inches added, the rpm at which torque and horsepower peak at will drop about 600 rpm. So, if your 460 horsepower peaks at 6000 rpm, a 545 will peak at 5000 rpm. This assumes not changing anything else in the engine combo.
2) If you wish to maintain the same horsepower and torque peaks when you increase the stroke, you need to add between 12 to 16 degrees of additional intake duration for every 50 cubic inches added in displacement. Respectively, exhaust will have to be increased also.
3) The amount of torque below the torque peak, and at peak, will increase. This is a good thing, especially for street cars.
4) The larger the engine, the faster it will pull rpm. The weight of the rotating assembly is almost the same on all strokes, from a 460 to the 545 assembly, but as you increase the stroke, the engine now has more displacement pushing that assembly.
5) If you keep the same cylinder heads on the larger motor, you need to add overlap by using a tighter lobe separation, usually 1 to 2 degrees for every additional 50 cubic inches, until you get to 270 degrees @ .050" lift. Above 270 @ .050" duration, you need to bring lobe separation wider to limit overlap that is inherent after that duration. BSFC numbers go up needlessly with too much overlap.
The tighter lobe separation angle adds the necessary overlap to feed the additional inches, however, it does close the intake valve earlier. The horsepower peak numbers will be similar, but will occur at a slightly lower rpm with the tighter LSA. It is usually good not to advance the cam as much as usual.
If your compression ratio is "on the edge" running on pump gas, it may be inapproopriate to tighten the LSA because it increases lower rpm cylinder pressures. The tight LSA adds low and mid range torque because of the lower end cylinder pressures, but may not be needed if the vehicle combo is traction limited. As an example, a street vechicle only running on street tires.
6) Peak horsepower will increase slightly.
Special Note
In regards to this chart, for every listed horsepower level, there is at least 10 different combos to get that same power. The builds outlined will get you the horsepower listed, but they are not the only way. Every individual's combo requires its own unique build. Some combos may need a lower profile manifold, some solid lifter cam only, and/or it needs certain parts to qualify for a specific class.
There are only 4 different cylinder heads shown for all these builds. There are other cylinder heads that can be used for each horsepower level, and in some cases preferred, once a person learns/knows what the other heads specifications are. This link: http://460ford.com/viewtopic.php?t=18321 will help you to learn about the other cylinder heads available.
In conclusion, this chart cannot be everything to everyone. Think of this chart as just as a guide-line to get you started in the right direction.
Before diving into the horsepower charts, a few items need to be clarified first. This is for 460 Ford motors with 4.36-4.44-inch bores and 3.85-inch stroke. These charts are for new members, either just getting into engines or coming from a different motor and wanting to know the particulars about building a 460, and for seasoned Ford 460 users wanting to know how to attain a certain horsepower from their combo. It is not a pump gas only list. It is designed to give the best overall performance for a given hp range.
A brief note on detonation. If you build a motor to the ragged edge of pump gas, and it detonates, you lose horsepower and you will harm the motor. It is better to sacrifice a little power (4% per point) and use less compression. If you are determined to use high compression, use race gas. It is cheaper in the long run than to harm your engine with detonation. Octane requirements have been noted in the builds.
Basic Suggestions
The intake system
It can not be stressed enough how important the carburetor is to the build. It will determine how the vehicle runs, not only at WOT, but at all the other speeds as well. A box stock Holley Double Pumper (DP) is set from the factory rich. People often complain of poor gas mileage from the DPs because they use them on their street vehicles straight out of the box. The idle and cruising circuits are very rich, and it takes a professional carburetor tuner to get the DPs set-up properly for the street. Not only for street use, but racing use also needs the carburetor to be set-up properly. The money spent on a professional carburetor tuner pays for itself, especially with the price of gas nowadays.
Cylinder heads
This is the area where you will have, or have not, the horsepower you’re seeking.
A good thread for information on the cylinder heads used in these build-ups and other heads can be found here:
http://460ford.com/viewtopic.php?t=18321
At every horsepower level, the cylinder head should be purchased from a professional cylinder head shop/porter. There is power to be found in doing a correct valve job even at the lowest of hp levels.
Furthermore, the TFS heads and P51 are mass produced items. A professional can get them "dialed-in". Do not think because you paid X amount of dollars that the head is perfect. Sometimes, not always, they need a little touching up for them to flow like they should out of the box, a lap job for the valve seal, etc.
Shortblock info
A word on basic machining. The basic part recommendations in each horsepower level increases as rpm rises. It is rpm, and not horsepower that requires the better parts. The time spent at the higher rpms also affects part selection. When in doubt, it never hurts to upgrade parts. The parts suggested at each build level will be able handle the rpm with good machining.
Good machining starts with making sure all parts are sound. All steel parts should be magnaflux crack tested, and all aluminum parts with zyglo. Every part should be checked, even new parts, to make sure they have correct measurements. If you find measurements to be off, have them corrected. Even though machining in it itself does not add a significant amount of power between the best job and a poor job, the life of the engine can be affected greatly. The higher the rpm, the more critical and costly the machining becomes, due to the machinist having to mock up multiple times, setting up his equipment to get the machining “spot on”, and checking and rechecking engine measurements. Be aware also that aftermarket “race” components often require “fitting” to make them work. They typically do not just bolt-on.
On 400 to 550 hp builds, it is prudent to find a good machinist/engine builder. Past the 550 hp mark, it is best not only to find a good machinist/engine builder, but one who is familiar with building 460s. There are minor things that can make or break the combo beyond 550 hp.
The stock crank, 2-bolt mains, and factory bolts are good to the 675-700 horsepower build which after the block should be 4-bolted. It is rpm again, for the need to 4-bolt. Anytime rpm exceeds 7500 rpm, aluminum rods should be considered, as cap walk starts to show up after that rpm with steel rods.
Paul Kane’s website on oiling mods:
http://www.highflowdynamics.com/
Quench
There is more power than just raising the compression by using quench. Here is a quote from Scott Johnson and Paul Kane on the subject of the importance of quench and engine performance. In all the engine builds, this is factored in.
Exhaust system
It is important to use a free flowing muffler in all the builds. Flow- Masters do not flow enough. Any muffler were you can pick it up and look thru it, without barbs or such protruding into the airflow will be a good flowing one. If noise is a concern, then a termination box should be built and then mufflers. You are striving for no back pressure.
Adding a stroker kit
Some have asked about a horsepower chart for stroker kits. Some of the most common are:
4.39 bore x 4.15 stroke = 502 cubic inches
4.39 bore x 4.3 stroke = 520 cubic inches
4.39 bore x 4.5 stroke = 545 cubic inches
By adding a stroker crankshaft, the following occurs:
1) For every 50 cubic inches added, the rpm at which torque and horsepower peak at will drop about 600 rpm. So, if your 460 horsepower peaks at 6000 rpm, a 545 will peak at 5000 rpm. This assumes not changing anything else in the engine combo.
2) If you wish to maintain the same horsepower and torque peaks when you increase the stroke, you need to add between 12 to 16 degrees of additional intake duration for every 50 cubic inches added in displacement. Respectively, exhaust will have to be increased also.
3) The amount of torque below the torque peak, and at peak, will increase. This is a good thing, especially for street cars.
4) The larger the engine, the faster it will pull rpm. The weight of the rotating assembly is almost the same on all strokes, from a 460 to the 545 assembly, but as you increase the stroke, the engine now has more displacement pushing that assembly.
5) If you keep the same cylinder heads on the larger motor, you need to add overlap by using a tighter lobe separation, usually 1 to 2 degrees for every additional 50 cubic inches, until you get to 270 degrees @ .050" lift. Above 270 @ .050" duration, you need to bring lobe separation wider to limit overlap that is inherent after that duration. BSFC numbers go up needlessly with too much overlap.
The tighter lobe separation angle adds the necessary overlap to feed the additional inches, however, it does close the intake valve earlier. The horsepower peak numbers will be similar, but will occur at a slightly lower rpm with the tighter LSA. It is usually good not to advance the cam as much as usual.
If your compression ratio is "on the edge" running on pump gas, it may be inapproopriate to tighten the LSA because it increases lower rpm cylinder pressures. The tight LSA adds low and mid range torque because of the lower end cylinder pressures, but may not be needed if the vehicle combo is traction limited. As an example, a street vechicle only running on street tires.
6) Peak horsepower will increase slightly.
Special Note
In regards to this chart, for every listed horsepower level, there is at least 10 different combos to get that same power. The builds outlined will get you the horsepower listed, but they are not the only way. Every individual's combo requires its own unique build. Some combos may need a lower profile manifold, some solid lifter cam only, and/or it needs certain parts to qualify for a specific class.
There are only 4 different cylinder heads shown for all these builds. There are other cylinder heads that can be used for each horsepower level, and in some cases preferred, once a person learns/knows what the other heads specifications are. This link: http://460ford.com/viewtopic.php?t=18321 will help you to learn about the other cylinder heads available.
In conclusion, this chart cannot be everything to everyone. Think of this chart as just as a guide-line to get you started in the right direction.
