What is the difference in the HP and torque that one cam will make to the other.
And how fast the bike will wind up.
And the life and durability of the engine and cam and componets.



And question 2

If you leave and go to a 590 to a 610 lift.

now you've gone to a High lift cam that required different cam springs.

What is the difference in the HP and torque that one cam will make to the other.
And how fast the bike will wind up.
And the life and durability of the engine and cam and componets.


And how much are you gonna have to worry about the quality of gas you will have to run.

 

a lot of other variables come into play besides lift. duration, valve timing, lobe spread, overlap. you need to look at the overall make up of the cams. intake opening and closing has a lot to do with how early, late or wideness of the torque curve. on the other forum there is a sticky on how each of the aforementioned variables influence hp/tq curves.


http://www.*****************/forums/tw...bers-mean.html

 

O.K.
Here is what somebody else posted.........



Aside from lift, cam duration probably has more impact on rideability and where the power is applied than any other cam characteristic. I found this understandable explanation of cam duration in my archives and am posting it for any that are considering a cam change. There are singel and dual profile cams but that should be a subject for another thread.

Duration has a marked affect on a cam's power band and drive-ability. Higher durations increase the top-end at the expense of the low end. A cam's "advertised duration" has been a popular sales tool, but to compare two different cams using these numbers is dicey because there's no set tappet rise for measuring advertised duration. Measuring duration at 0.053-inch tappet lift has become standard with most high-performance cams. Most engine builders feel that 0.053” duration is closely related to the RPM range where the engine makes it's best power. When comparing two cams, if both profiles rate the advertised duration at the same lift, the cam with the shorter advertised duration in comparison to the 0.053” duration has a more aggressive ramp. Providing it maintains stable valve motion, the aggressive profile yields better vacuum, increased responsiveness, a broader torque range, and drivability improvements because it effectively has the opening and closing points of a smaller cam combined with the area under the lift curve of a larger cam. Engines with significant airflow or compression restrictions like aggressive profiles. This is due to the increased signal that gets more of the charge through the restriction and/or the decreased seat timing that results in earlier intake closing and more cylinder pressure. Big cams with more duration and overlap allow octane-limited engines to run higher compression without detonating in the low to midrange. Conversely, running too big a cam, with too low a compression ratio leads to a sluggish response below 3,000 rpm. Follow the cam grinders recommendations on proper cam profile-to-compression ratio match-up.

Duration generally ranges from 220 degrees for a torquey bottom-end cam all the way to 295 degrees for a “top end rush,” typically measured at 0.053 inch lift.

As a general rule, lower-duration cams in the neighborhood of 210 to 200 degrees at 0.053 work best for stock-type replacement cams. Stepping past 220 degrees of duration (at 0.053) places the cam into the bolt-on, mid-range style category. These cams work well with the stock compression, intake and exhaust. Cams with 240-plus degrees of duration or more are beginning to step into the performance arena and generally work better with other induction, compression, and exhaust modifications. Duration has a marked affect on the cams power band and drivability.

Higher durations increase the top-end at the expense of the low end. As a general rule, cams with 220-235 degrees of duration tend to produce good low end torque. Cams with 235-250 degrees of duration tend to work best in the mid-ranges and cams over 260 degrees work best for top end power.

It is important to remember here that the duration values given are to be used as a general rule and that increasing the duration will have an effect on the idle characteristics and overall drivability.

Long duration, late intake closing cam designs are necessary to drag the last bit of power out of an engine. Unfortunately, these same cams can perform poorly under more normal riding conditions. In the quest for maximum power output, many (too many) Harley owners choose a late closing, high-rpm cam for their engine. The problem with such choices is that the engine seldom spends time in the rpm range favored by such cams.
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i guess you answered your own question?

 

Too many other variables to answer the HP/TQ question quantitatively; the most important of which is compression. Some guys will get the Big Boyz stree port job along with a set of SE204 cams and pick up 10TQ/10HP from the headwork. But the head work included equalizing chamber volume and decking for compression; much of the increae in performance came from the added compression. You have to factor in headwork, exhaust, and most importantly tune.

As long as the engine was setup properly, longevity and dependability should not be an issue with cams under .570" lift. Most of these cams can be run with the factory beehive springs.



Same answer as to Question #1 on HP/TQ. Personally, I don't see the need to go over .570" lift for most street builds. Valve train geometry starts to come into play which can generate noise and can affect valve train longevity. Is it worth an extra couple of foot pounds of TQ to listen to a noisy valve train or have a pushrod adjustor come loose or bend a pushrod, or worry about floating a valve and making contact with a piston? not for me.

With the new 1.725 ratio rockers, you can take .525" lift cam and increase lift to .557", stick with stock springs and see some mid range improvement.

If you want the engine to rev up faster, gear down the primary; that's a torque multiplier.

Compression is going to determine the quality of gas you can run. Keep corrected below 9.3 and cranking below 190psi and with a good tune, fuel shouldn't be a problem.

 

Thank you very much DJL

O.K.

I have a 2008 FLHT with a 103 engine. R&R Stage II heads, flat top pistons, Tw6 woods cams. PCV tuner.
A/N BS 2 air box.
I chose the compression ration of 9.8.1
Supertrapp 2in1 pipes

I had people trying to git me to to to 10.5 up to 12.1 compression. I was scared the crank might hold up since its stock.

Scared I might git into the desert or somewhere and not be able to find real good gas.
Or the goverment will come out with a higher ratio of Ethanol.

I see everybody wanting to git higher and higher lift cams to make more and more power.
For ridability reasons, I ain't building A DRAG bike.

The TW6 woods cam is a 510 lift and comes in at around 1400 and winds up to it hits redline at 5300rpm.
If I left the TW6 Woods and went to say the Woods 555 cam which is 555 lift or the TW7 woods cam which is a 575 lift cam.

Leaving the bike with the same setup and just changin the cams what rewards would I git .

I know that you can build a engine to make more hp. But I know you can build a engine to make power faster with a Bagger and 2 people riding.
I twist the throttle pretty hard.

What i want is for a engine to go from Point A to point B the fastest.

With what I am askin could you suggest any improvements

 

I believe that the cam can show you more, as we have witnessed dyno reports from T-Man's dyno(just said this in another thread) show 110/110 sae, from our 98"/Stage III heads, bored Delphi, D&D Fatcat combo, and have witnessed the same here. Nothin' speacial about doing that.
That cam is fine to run at 10.25, and that is where we sign off at with the squeeze.
Let us know if we can help.
Scott

 

Gains from cam changes impact rideability at times. If you have a cam set up at the correct CR and the cam comes on exactly where you ride the most, then "stepping up" will at times be disappointing. In most cases, the more your increase duration and lift, along with a later intake closing, the power band moves to the right. Also, the gains you see from going from, say a Wood 6 to a Wood 555 would be minimal, but the power band will move. You will not see a gain like you did when you went from stock to the Wood 6.

Same with a HQ 525 set at 9.5:1 vs a HQ 575 in the same engine, small gains in power, but moving the power band a bit to the right. Now, increase the CR to 10.5:1 and increase is more noticeable as CR is where it needs to be for the cam.

Also, just changing from brand to brand could be an exerccise in futility once the engine is built as you may see gains in certain rpm ranges, but then again you can also see losses in others and again, rideability that you are comfortable with may change.

It is difficult once you have built an engine for a particular configuration to just throw parts at it and expect big increases. Your engine is pretty much optimized as is.

 

Talked with you a year ago Scott. Hate I got swayed somewhere else.

So with yer stage II heads I will notise a difference.
ARe you gonna want to move my compression ratio up to 10.25 and I guess yer gonna use compression releases.

excuse my not knowing but what is bored Delphi, is this boring the cylinders ?

 

I don't know anything about the R&R Stage II heads but I believe you can get some improvement with the TMan 555 cam if you set it up as he advises. IIRC, he will tell you that the 555 will need 190psi cranking compression at a minimum. Without getting into calcs, that will likely mean some additional machine work on the heads to get the CR to about 10.3 or thereabouts.

Scott is talking about boring the throttle body but he was referring to the two piece unit and I believe the later units were one piece??