My Flat Tappet Cam Wiped Out So I Decided To Go Roller

[0xDEADBEEF]

Torque not RPM is what moves a heavy vehicle.

It's both ... aka horsepower.

Torque is a force, not a measure of work. It takes work to move something.

 

[L31MaxExpress]

It's both ... aka horsepower.

Torque is a force, not a measure of work. It takes work to move something.

A Diesel semi has ~600 hp and so does a supercharged gas V8. Difference is the semi makes 2,500 ft/lbs of torque where the gas V8 might make 550. As I was saying at lower rpm like you drive around at 95% of the time, torque is what is needed to move a heavy truck. More torque at the same rpm is more hp.

The 6.0L I tuned the other night. ~480 tq @ 4,500. Off the line it is not nearly as snappy as my 383 that makes 500+ @ 3,500 even though it is pulling around another 1,000 lbs and has a 3.73 gear opposed to a 4.10. At 70-80 mph my 383 will grunt its way up a 6-8% grade at ~2,300 rpm without having to even unlock the converter and that was rolling along at 7,500# across the scales.

 

[L31MaxExpress]

This 383 was run on engine dyno and is nearly a carbon copy of what I am running. Lloyd Elliot ported the heads on both, same compression ratio, virtually identical cam. They both make big midrange torque numbers. When you make ~500 ft/lbs at 3,500 and peak power under 6K, there is no need to spin the thing crazy high, have a super loose converter or deep gears. This engine can be shifted at 5,500 rpm and still fly.

You must be registered for see images attach

 

[0xDEADBEEF]

A Diesel semi has ~600 hp and so does a supercharged gas V8. Difference is the semi makes 2,500 ft/lbs of torque where the gas V8 might make 550. As I was saying at lower rpm like you drive around at 95% of the time, torque is what is needed to move a heavy truck. More torque at the same rpm is more hp.

The 6.0L I tuned the other night. ~480 tq @ 4,500. Off the line it is not nearly as snappy as my 383 that makes 500+ @ 3,500 pulling around another 1,000 lbs.

The math to move an object doesn't care about torque. The math to make horsepower does. There's a practical limit to how much torque multiplication through gearing we can achieve in a given footprint.

The engine that can do the most work (horsepower) is going to accelerate faster, tow more, etc. and most of the time in street car/truck life that engine makes more torque too.

 

[L31MaxExpress]

The math to move an object doesn't care about torque. The math to make horsepower does. There's a practical limit to how much torque multiplication through gearing we can achieve in a given footprint.

The engine that can do the most work (horsepower) is going to accelerate faster, tow more, etc. and most of the time in street car/truck life that engine makes more torque too.

Torque is what turns the tires, not horsepower. Torque is the measure of drive force that gets you rolling. You could have 5,000 hp at 10,000 rpm and without torque multiplication it will not move a vehicle 1". If you had endless torque multiplication a 2 stroke weed eater engine could move a semi or a freight train. Given that we do not have endless torque multiplication and want an engine with low stress for engine life, it is better to have more torque and less rpm to make a given power. More cubes, longer stroke, more torque and power.

 

[0xDEADBEEF]

Torque is what turns the tires, not horsepower. Torque is the measure of drive force that gets you rolling. You could have 5,000 hp at 10,000 rpm and without torque multiplication it will not move a vehicle 1". If you had endless torque multiplication a 2 stroke weed eater engine could move a semi or a freight train. Given that we do not have endless torque multiplication and want an engine with low stress for engine life, it is better to have more torque and less rpm to make a given power. More cubes, longer stroke, more torque and power.

No, torque does not "do" anything.

There's an infinite number of ways to get the same amount of work done. Better is somewhat subjective.

 

[L31MaxExpress]

No, torque does not "do" anything.

There's an infinite number of ways to get the same amount of work done. Better is somewhat subjective.

Torque is what makes things move. HP is a calculation. Zero rpm = Zero HP. Torque is the twisting force that sets things in motion. You cannot have horsepower without having torque.

 

[0xDEADBEEF]

Torque is what makes things move. HP is a calculation. Zero rpm = Zero HP. Torque is the twisting force that sets things in motion. You cannot have horsepower without having torque.

How much torque does a 737 put out while it's moving 50 tons down the runway?

 

[L31MaxExpress]

How much torque does a 737 put out while it's moving 50 tons down the runway?

That is something etirely different. That is thrust not HP. Rockets also make thrust not horsepower. Propellors convert torque and thus HP into thrust.

 

[0xDEADBEEF]

That is something etirely different. That is thrust not HP. Rockets also make thrust not horsepower. Propellors convert torque and thus HP into thrust.

It is different. Horsepower is just a different unit for work. Work is what we are really talking about when we move things like trucks.