Horsepower & Torque

[FLTR2008TRIKE]

I read other forums and this one as well and the one thing I read a lot of is everyone want more horsepower.

Harley are by design made to make torque!!! When your wanting more power THINK TORQUE!!! The torque is what makes the mass move. The more torque you make the easier the engine can move the mass!! The easier the engine works the less heat it will make

Horsepower equals heat. The faster the engine spins the more frictions it creates!!

Making more torque to move your trike with the stock engine size in the usable rpm range we ride can be done. But it comes with a cost. Making torque requires changing the restrictive air cleaner and using a exhaust that will give good flow at the rpms we ride in. Raising the stock compression slightly by removing the thicker head gasket and installing a thinner one.

Changing the stock cams to a cam that is designed to allow the engine to make better use of the other changes to the system and then add a good tuner with a tune by a knowledgeable tuner person and you will raise the amount of efficient potential torque in your stock trike engine that should have been done by Harley to start with!!! Do this and you can still keep the engine heat manageable if not lower while riding

Increase the displacement and you will continue to raise the amount of torque and horsepower.

Here is a link that is best description of it all >>

Engine Build Basics

 

[THEREALTRIKKY]

Another "poor boy" method I've read about that people seem to "love" is changing the larger front pulley (rear drive belt) to a smaller version. Harley started doing this with the Tri-Glide as well. For example, if you have a 32 tooth front, going to a smaller 30 tooth will give you an improved "response" in your bike.

 

[FLTR2008TRIKE]

Another "poor boy" method I've read about that people seem to "love" is changing the larger front pulley (rear drive belt) to a smaller version. Harley started doing this with the Tri-Glide as well. For example, if you have a 32 tooth front, going to a smaller 30 tooth will give you an improved "response" in your bike.

Agreed, this does increase the mechanical torque output the driveline but doesnt address the heat issue with the restrictive setup of the engine. If you made changes to both the engine and sprocket you would have so much more power overall.

 

[JJTRIKER]

Engine fan is the word

 

[FLTR2008TRIKE]

And that fan will be turned on sooner on a stock engine setup. Why is that?? Read my first post

 

[grapenuts]

Here's an interesting question. Say you're riding along on the highway and you come up on a slower moving truck. You're going to pass but time is important. Assuming a stock HD 103 makes max torque at 3400 rpm and max hp at 4900 rpm, when you downshift and pull out to pass are you going to limit rpm to 3400 or are you going to use that horsepower? Take a look at your tach the next time you're "pouring the coals" to your bike (a different scenario than leisurely going through the gears).

I've got an RV with a diesel engine that puts out 400 hp @ 2100 rpm and 1200 ft/lbs at 1400 rpm. When I'm attacking a steep grade I'm at max hp not max torque. From what I've read, torque is the force that gets you moving and HP is what keeps you moving.

 

[FLTR2008TRIKE]

HP & TQ measured at the rear wheel will not equal the the same numbers most engine manufactures posted at the crank. When you see dyno numbers for anything engine related (and even Harley does this with engine packages they offer for Screamin Eagle engine parts) are measured at the crank. Most post dyno numbers as measured from the crank and some post from the rear wheel.

 

[FLTR2008TRIKE]

Here's an interesting question. Say you're riding along on the highway and you come up on a slower moving truck. You're going to pass but time is important. Assuming a stock HD 103 makes max torque at 3400 rpm and max hp at 4900 rpm, when you downshift and pull out to pass are you going to limit rpm to 3400 or are you going to use that horsepower? Take a look at your tach the next time you're "pouring the coals" to your bike (a different scenario than leisurely going through the gears).

I've got an RV with a diesel engine that puts out 400 hp @ 2100 rpm and 1200 ft/lbs at 1400 rpm. When I'm attacking a steep grade I'm at max hp not max torque. From what I've read, torque is the force that gets you moving and HP is what keeps you moving.

I can beat that your 400 hp diesel engine has twice the torque as hp @ 2100 rpms. So the torque is still moving the mass. The HP helps sustain the motion at the higher rpm range

Please read this short article and when you get to the last line statement it will back up what I stated from the beginning>> http://www.perfprotech.com/blog/articles/torquevshp

Bottom line, ANY engine that produces more torque in the normal operating rpm range will have more horsepower and work less move the mass and maintain speed.

 

[FLTR2008TRIKE]

I found this statement and had to post it >>>

"Displacement is King, Torque is Queen, and Horsepower is the Court Jester"

 

[grapenuts]

I'm not trying to argue any particular point it's just that discussions on HP & torque are very interesting. The article you cite is just an opinion piece, albeit an opinion based on experience. Torque is simply a value of twisting force while horsepower is a measure of work done. I can use a pipe wrench to apply measurable torque to a fence post but unless I actually cause it to move, I haven't done any work (I think).

But all are correct when they say to build an engine to meets its intended use. A typical V twin likes to poke along at 2500 to 3500 rpm where torque, not horsepower is king. Above 5250 rpm, it's probably the reverse. I'm no scientist but I did stay at a Holiday Inn Express last week.

 

[msocko3]

I'm with FLTR2008TRIKE, torque is what trikes need. HP is something that is nice but it doesn't get the mass moving. Most people will never see what the max HP does for them because they won't be in the top RPM ranges where HP takes over. A nice long torque curve makes an engine seem like it just keeps on pulling.

The need for a good low end torque is what makes cam selection for a trike a tricky little dance. Most cams which make big low end torque do so by having an early intake close which increases the CCP, higher compression means bigger bang, bigger bang means bigger kick in the pants. The down side is if you squeeze the air fuel mixture to much then add low RPM's and lots of work you run the risk of preignition. The only way to over come that is to pull timing out, pulling timing out reduces the power and torque you are able to develop in that RPM range, to over come this you either have to drop the compression or use a higher octane gas. Some will agree and some will disagree, I don't like to see the CCP on an air cooled HD engine in a heavy trike above 185 - 187 CCP. With that compression and the right tune you can make decent torque and still have fuel flexability.

When I was out west in 2011 I filled up with 89 octane that contained 10% ethanol, I climbed some pretty good grades in 85 - 90 degree weather without a single ping from the engine. My CCP with the Wood TW555 cams was 187, this was with bone stock heads and factory thickness head gaskets.

Since most of us travel to places far from home we are at the mercy of the gas stations along the way. I've been on trips where the only thing available is 87 octane. When the choice is run out of gas or pump in 87 octane its a pretty easy choice, pump in the 87 octane and hope you remembered to pack the octane booster.

 

[Phu Cat]

Torque times RPMs= horsepower, it's that simple. If you look at your engine as an air pump it might be easier to understand. The more air you move thru the engine (assuming F/A ratio, valve and ignition timing, etc are optimum) the more power it will make.

Increasing torque at the same RPM will make more horsepower. Increasing RPM at the same torque will also make more HP. Matching parts that will complement each other is the best idea. Putting random 'high performance' parts in an engine may increase its power, but probably not as much as parts that are known to complement each other.

Phu Cat

 

[Bill Reber]

All I know is if I twist the thing on the left my grin increases as others fade into the background !

 

[PIGGI]

All I know is if I twist the thing on the left my grin increases as others fade into the background !

Are you riding an old Triumph?

 

[Sloufoot]

All I know is if I twist the thing on the left my grin increases as others fade into the background !

Must be crankin on the spark !:Trike1:

 

[Bill Reber]

poof It's the age monster , but you guys got a chuckle out of it and it does show you pay attention , go to the front of the class ! LOL

 

[eighty80]

Bill Reber,....

That ain't right in what you did!! I had to go out to the shop, in the rain to check mine.

I owe you one........

 

[bobscogin]

q

q

I read other forums and this one as well and the one thing I read a lot of is everyone want more horsepower.

Harley are by design made to make torque!!! When your wanting more power THINK TORQUE!!! The torque is what makes the mass move. The more torque you make the easier the engine can move the mass!! The easier the engine works the less heat it will make

Horsepower equals heat. The faster the engine spins the more frictions it creates!!

There may be some basic misconceptions in your statements. Torque is not a measure of the rate of work. It is a measure of force. Moving mass requires work done at a certain rate. The measurement of work done moving that mass is the horsepower unit. In fact, you can have a zillion pounds foot of torque but it doesn't produce "work" until a time/distance factor and a specific mass is specified. I think a better way to express what you're saying is that you want the engine to be in a state of tune such that it delivers peak torque at lower rpm, thus creating it's peak horsepower at lower rpm. This explains it in detail.Power and Torque: Understanding the Relationship Between the Two, by EPI Inc.
Torque is a factor in horsepower, but it doesn't do the work without rpm to make power.

I'm uncertain about what you mean when you say horsepower equals heat. Actually, heat equals horsepower. 1 HP equals 2,545 BTU, so the more BTU, the more horsepower. Twisting the throttle open equals more fuel and air, more BTU, and more horsepower.

Bob

 

[FLTR2008TRIKE]

Re: q

q

There may be some basic misconceptions in your statements. Torque is not a measure of the rate of work. It is a measure of force. I agree!!

Moving mass requires work done at a certain rate. The measurement of work done moving that mass is the horsepower unit. POWER (the rate of doing WORK) is dependent on TORQUE and RPM.

In fact, you can have a zillion pounds foot of torque Torque = rotational force eventually expressed in pounds at one foot radius

but it doesn't produce "work" until a time/distance factor and a specific mass is specified. RPM = time and distance, i.e. distance in circumference at the one foot radius The given for this is the stock engine already installed in a trike and I agree No torque or HP is made until the engine is running

I think a better way to express what you're saying is that you want the engine to be in a state of tune such that it delivers peak torque at lower rpm, thus creating it's peak horsepower at lower rpm. This explains it in detail.Power and Torque: Understanding the Relationship Between the Two, by EPI Inc.
Torque is a factor in horsepower, but it doesn't do the work without rpm to make power. Horsepower = torque X rpm / 5252

There is no horsepower without torque and rpms. Again raise the torque output with the rpms of your existing engine you will raise the horsepower. Below 5252 rpm any engine's torque number will always be higher than its horsepower number, and above 5252 rpm any engine's horsepower number will always be higher than its torque number. At 5252 rpm the horsepower and torque numbers will be exactly the same.

I'm uncertain about what you mean when you say horsepower equals heat. Actually, heat equals horsepower. 1 HP equals 2,545 BTU, so the more BTU, the more horsepower. Twisting the throttle open equals more fuel and air, more BTU, and more horsepower.

In the simplest terms I can think of, If you rub your hands together fast enough is that not heat caused by friction? To achieve a horsepower rating the engine must spin faster for peak horsepower to over come peak torque which is above 5250 rpms. Rub your hands slower and you create less heat.

There will always be heat from the combustion within the chamber . But if you speed up the rpms of any engine the heat from the friction goes up as well. Since we ride a air cooled engine the microscopic layer of engine oil is protecting the piston rings from scoring the cylinder walls the pistons ride in. Obviously the cooler we can make the engine run the longer it will hopefully last.



My intent was to help those gain a little better understanding of what they can do to improve the power the stock engine HD builds and installs. The 103 is lacking in stock form. I know I rode my trike with one at one time and if it was in a 2 wheel bike it would have been a good engine. But in a trike it was lacking the torque it needed when riding in the mountains.

Here is another page from Clark Hemrick an engine builder who sadly may no longer be among us due his battle with terminal cancer, but was extremely knowledgeable about Harley engines and how to get them to run the way they should from the start. >>

Info. For The New Harley Owner

Tom

 

[bflonez]

This seems to be the correct place for my question. I have a 2006 Road Glide / CSC with TC 88. I added Andrews 26 cams, adjustable pushrods, billet cam plate, fuelig oil pump, oil cooler. Now I would like to add a big bore kit and head work. Will the 26 cams be correct for a touring trike? I will be pulling an Alumin MCTXL and feel a displacement increase will help. Any advice will be greatly appreciated.

 

[FLTR2008TRIKE]

This seems to be the correct place for my question. I have a 2006 Road Glide / CSC with TC 88. I added Andrews 26 cams, adjustable pushrods, billet cam plate, fuelig oil pump, oil cooler. Now I would like to add a big bore kit and head work. Will the 26 cams be correct for a touring trike? I will be pulling an Alumin MCTXL and feel a displacement increase will help. Any advice will be greatly appreciated.

From what I have read on this cam for a 95" engine the Andrews 26 cam will work. Cleaning up the heads a little for better flow will be ok and maybe mill the heads to 85cc with .035 gasket squish will set your
static compression @ 9.40
corrected compression @ 8.82
CCP @ 180.5

The Torque & HP wont be great but this should net you some more power over all and still be a cool running engine

You should also talk to these 2 in Florida to get the professionals opinion

Doc >> http://docsperformancetuning.com/engine-builds.html

Kirby >> VEE-TWIN Performance Center - High Performance Machining and Services for Harley Davidsons

Tell them what you are wanting to do and see what they suggest

 

[Rick Kay]

This seems to be the correct place for my question. I have a 2006 Road Glide / CSC with TC 88. I added Andrews 26 cams, adjustable pushrods, billet cam plate, fuelig oil pump, oil cooler. Now I would like to add a big bore kit and head work. Will the 26 cams be correct for a touring trike? I will be pulling an Alumin MCTXL and feel a displacement increase will help. Any advice will be greatly appreciated.

I have the 95" conversion, running with SE 10:1 pistons, SE 203 cams, SE Street Performance Tuner, 52mm injector, SE cam plate and oil pump. I'm very happy with the performance, but am going to change to a 30 tooth pulley in the near future. I would suggest you do the pulley change and evaluate the performance before you spend more money on the motor.

 

[ttanthony]

Very interesting thread. I have enjoyed reading it. And now I can finally say something good about winter. I'm sure if this was a warm summertime. All of you find gents would be out riding instead of writing all of these crystal clear gems of wisdom. Great job, thank you.

 

[bflonez]

Thanks all for the input on a 95 in kit. Great ideas for me to consider. I will check the 2 Florida links for sure. Here in Fort Myers I take mine to The Haus of Trikes. Great shop.

 

[FLTR2008TRIKE]

Thanks all for the input on a 95 in kit. Great ideas for me to consider. I will check the 2 Florida links for sure. Here in Fort Myers I take mine to The Haus of Trikes. Great shop.

Hope it works out for you as you want ThumbUp

 

[lboos]

Very interesting subject.

 

[jackthemachinist]

>I have a 2006 Road Glide / CSC with TC 88. I added Andrews 26 cams, ... oil cooler. Now I would like to add a big bore kit and head work. Will the 26 cams be correct for a touring trike? I will be pulling an Alumin MCTXL and feel a displacement increase will help. Any advice will be greatly appreciated.

The Andrews 26 cams will work very well with your proposed combination (95 inches and headwork). I like to use a 1.900 intake valve and 1.625 exhaust. I recommend taking 0.025. off the heads. I agree you many want to change gearing a bit. I'd go a tooth less on your compensator sprocket. To me, it's easier to change than the drive pulley.

 

[Mr.Wizard]

OK you brainiacs... Can this be moved to the other side of the isle so others here can understand?

Let's say I'm a rider who just loves to ride but I want to mod my motor for a little bit more power, sound and less heat. I want to get the ego trip while being able to stay economical. I want good manners from my motor and longevity. Now, keep the explanations easy to follow and how it will effect my future decisions to meet my goal. AND, I don't want to click on links and keep reading articles that get me lost. :gah:


Torque? Horse Power?? Heat??? CCP???? Tuning????? Octane?????? WHAT ARE YOU GUYS TALKING ABOUT???????


There ya go Tom. And no, I ain't going to help.... HAHAHAhhhhaaaa

 

[Rick Kay]

>I agree you many want to change gearing a bit. I'd go a tooth less on your compensator sprocket. To me, it's easier to change than the drive pulley.

That's a great idea, thanks!

 

[msocko3]

OK you brainiacs... Can this be moved to the other side of the isle so others here can understand?

Let's say I'm a rider who just loves to ride but I want to mod my motor for a little bit more power, sound and less heat. I want to get the ego trip while being able to stay economical. I want good manners from my motor and longevity. Now, keep the explanations easy to follow and how it will effect my future decisions to meet my goal. AND, I don't want to click on links and keep reading articles that get me lost. :gah:


Torque? Horse Power?? Heat??? CCP???? Tuning????? Octane?????? WHAT ARE YOU GUYS TALKING ABOUT???????


There ya go Tom. And no, I ain't going to help.... HAHAHAhhhhaaaa

I'm going to try and keep this simple and hope I can answer some questions, To truly explain how everything Wiz mentions comes into play would take a very long writeup, don't think my hands would like it very much.

Here's my 2 cents or my twisted way of looking at the world or performance surrounding heavy bikes and trikes with traveling and poor fuel quality in mind.

I'm a Torque junkie, the simplest way to describe it is that feeling you get when you start twisting that throttle and you feel the bike or trike pull, that wonderful stretch your arms out pullpepper.

When I mentioned my twisted thoughts above concerning traveling and availability of good quality of fuel, octane and compression along with the weight of the bike or trike weighs heavily on my mind, its a balancing act. Octane is a measurement of the fuels ability to resist detonation at a given compression. As we have all learned traveling the wonderful country we can and will run into varied octane rating and fuel formulations.

Some I've come across, everyone knows good old 87 octane, then you get a bump to 89 octane, 91, 93 and in some states you may see 94. The higher the number the more resistant the fuel is to detonation. When I choose a camshaft and tune for both my dads 09 Triglide and the 10 Triglide I used to own, fuel quality was one of my biggest criteria. I did run 89 octane with 10% ethanol while out west with not a bit of problems, I believe I could have also run 87 octane and got away with it, flexibility was what I was after and what I got.

This brings me to compression, people often read and hear terms such as 10.1, 10.5:1 etc. The majority of the time people are describing what they call Static Compression. To keep this simple we will say this is the compression of the cylinder if you did not have cams installed to open and close the valves.

With the introduction of the cams to open and close the valves things change. This is when Dynamic Compression comes into play. The camshaft is your engines brain, through how far open, how long open and when they open and close can make or break a combination. The simplest way to explain dynamic compression is how much pressure the cylinder builds based on when the intake valve closes in relationship to how far up on the compression stroke the piston is. When the piston is on the way up on the compression stroke there is a period of time the intake valve is still open, this allows some of the pressure to bleed off into the intake tract, Depending how long the intake valve is open determines what your dynamic compression actually is.

An example would be the 103ci engine as it comes in the Triglide, if everything is as it should be the Static compression ratio should be in the neighborhood of 9.6:1. With the stock cams your Dynamic compression will be in the neighborhood of 9.1:1.

A way of measuring the compression is often talked about as CCP, or Cold Cranking Pressure. If you was to hook up a compression tester to the above mentioned engine with the push rods removed so the valves can't open or close you will see a cylinder pressure around 202 psi, now install the push rods and allow the cams to do their job you will see the pressure around 188 psi, this is due to the pressure being bled off because the intake valve is still open part of the way.

The intake valve closing is listed in degrees, stock Harley cams come in around 34 degrees ABDC. Now install a cam with a later intake closing you will bleed off more cylinder pressure. An example is a cam with an intake close of 40 ABDC, your dynamic compression would be 8.9:1 or a CCP of 182 which is 6 psi lower than the stock cam.

So how does compression relate to torque. The simplest way to explain it is the harder you compress the air fuel mixture the bigger the bang would be, of course a bigger bang means bigger torque. The down side to the bigger bang is increased heat and the chance you may have a fuel that starts to go bang before you want it to, this premature bang will result in the dreaded ping. Unfortunately not all pinging is audible, sometimes an engine can experience detonation or preignition without it being heard.

When choosing a cam bigger isn't always better, folks sometime choose cams based on how far they will open the valves. A lot of cams which open the valves quite aways also have very late intake closing points, keep in mind the later you close the intake valve the less dynamic compression you have, this will result in an engine which is a dog in the low rpm range. For instance using the 103 as mentioned above increase the intake close to 50ABDC and you would see a dynamic compression around 8.4:1 or a CCP of 171 psi. This is a pretty significant reduction in compression and will defiantly be felt in the seat of the pants. If you want to run a cam with a later intake close you have to have more static compression to compensate for the bleed off of the intake valve being open longer.

Of course we all want a little more performance (Or at least some do). To get more performance you have to open the intake and the exhaust valves farther. The heads on the modern Twin Cam 2006 to present will support a cam with an advertised lift of .575, this is the measurement of how far the valve is open in inches. The stock HD cam comes in with a .473 lift on both the intake and exhaust side. Once trick a cam designer will do is open either the intake valve more than the exhaust or vise versa to compensate for intake or exhaust port weaknesses, most modern bolt in cams for the newer Twin Cam engine have equal intake and exhaust opening.



With this being said, its getting late and I have a early 3:45am get up for work and 12 hour shifts, not to mention my fingers are getting tired. I'll let someone pick up and add to this little post. If I missed something or didn't explain it well enough by all means add to this, sometimes what is in my head doesn't translate into type written words very well.