The answer is right in front of you, or in the dyno section, 204 cams, V&H Power Duals with 4.5" Twin Slash Ovals, same design as the monsters.

 

I wonder if the OP is staying at 96" or punching out to 103" as his old build was? Reason I ask is the 54H is popular in the 103" build but wonder what it would be like in a stock 96" with a 4* sprocket? Can't say I've ever seen a 54H in a 96"??

 

Uh, you're "pretty happy" with the numbers? I would be elated. I would not have thought headwork would've made that much difference with the 255's, but you've proven that it does.

 

Out-of-the-crate really isn't a good environment to test anything, IMO, as it is set up to meet exhaust and noise emissions.

I must disagree. Many have replaced cams on a Stage 1 TC96 with 255's and have been very happy, and I'm a member of that club. They do very well with the stock 9.2:1 compression of the stock TC96 and no other mods, and it is the best bang-for-the-buck upgrade on a stock motor you can do if your quest is increased TQ where most of us ride, IMO, especially if you DIY and buy a low-mileage CVO pull.

As for "running out of steam" at 4500rpm I must respectfully disagree with that notion too. They produce a very flat TQ curve and make power all the way up to the extended redline (6250rpm) with no "hitting the wall" or perceivable drop-off in the process of getting there. They do not produce prodigious amounts of peak-HP and it is not their designed purposed to do so. These cams do not have a "band" where you feel a surge at a give point in the transition toward the redline, which is why may be why some suggest they "hit a wall." That's not the sensation I get when riding my bike, although I'll admit that I live above 4500 rpms only rarely, as the power is more than sufficient below that point, for me anyway. They do produce more peak-HP than stock, but not as much as most other cams on the market. For this reason they would be a poor choice if drag racing is your priority, but for real-world power where you ride I don't think they can be beat for the money spent.

 

+1 I too like the gains provided by the 255 cams in my Stage 1 96" (Rinehart True Duals, SE A/C w/K&N & PCV w/Auto Tune). However, that "taste" of added power has hungry for more so I'm sure a 103" with mild head work and probable cam change is in my future!

 

A bike with stock cams will run up to the rev limiter, but there's not much point in doing that. Twist the throttle hard at 2000 rpms. Feel the bike jump forward? Now run it up to 4000 rpms and do the same thing. With your se255 cams, your acceleration is going to be much more relaxed with no feeling of the bike jumping forward. That's the difference of being on the uphill or downhill part of the curve. That's how it feels when the cam runs out of steam. Se255 cams simply don't have enough duration to effectively fill the combustion chamber at high rpms. Some of you guys running these cams really should go ride a bike with a little more performance sometime.

If your "butt dyno" can't feel the natural limitations of the 255 cams, maybe it needs to be recalibrated.

 

There's indeed not much point in doing that with the 255's, but you're missing the point. Some of us value the left side of the TQ curve more than the right, and for normal riding you don't need to push it beyond that point.

How can this be? Both TQ and HP are much higher at 4000 than at 2000, and I don't get that comparatively "relaxed" sensation at all. The sensation I get is that the TQ curve is flat and not peaky. When comparing to something with a more radical cam set of course that setup will "jump forward" more at 4000 than 2000, mainly because it will likely have less TQ at 2000 and more of everything at 4000. What I must stress again is that by 4000 rpm I don't need to rev the bike any further, or at least rarely feel the need. There is sufficient power below 4000 to keep it at that point or lower in normal riding, even when passing.

Nobody is wrong here, and it's just a matter of what your preferences are.

I've been riding bikes for over 45 years from Honda 50's to crotch rockets, with many highly modified Harleys in between, and I'm familiar with the type of performance you are talking about. What I can't seem to get across is that for my type of riding on a touring bike I value the power more down low and in the midrange. That's not to say that I don't like riding more highly modified Harleys once in a while, but for my bike I would rather have the TQ curve shifted more to the left. You like it more to the right, and you aren't wrong. Neither am I, so please try to understand that everyone doesn't have the same needs.

Nobody here is saying the 255's don't have limitations, but in fact every cam has their strong points, and not one is right for everyone.

By suggesting that another person's butt dyno needs "recalibrating" suggests that you think only your idea of proper cam behavior is the correct one, and/or that everyone else is inexperienced or naive and won't find out 'til he or she rides a real motorcycle. Please, give us a break! I like the way the 255 cams behave in my bike, as well as the cost of the upgrade related to the effect achieved. I was actually quite happy with the performance of the stock TC96 with Stage 1 mods, but I made the cam upgrade only after long and hard deliberation where I considered many different combos. I wanted a bump in TQ in the low-end and midrange without shifting the curve to the right without spending much money, and that's exactly what I got. Mission accomplished, and a bargain for $285 total cost (including a $95 inner-bearing tool).

 

Bob, you completely missed my point. The natural limitations of the 255 is that they fall off at higher rpms. It's due to the short duration and simple physics. It's not about what I prefer, although I do prefer a little more performance in my bike than the 255 can deliver. I don't like it "more to the right" as you said, I like a more balanced torque curve. I want to raise the entire range, not just concentrate on one end.

It's not an attack, you shouldn't take it so personally. All equipment needs calibration from time to time and if the only thing you are using is your "butt dyno" as you've posted so many times, then you might consider a recalibration. That's a lighthearted reference. If you found offense in that, you were reading way too much into it. Next time I'll try and remember to add a

 

I didn't miss your point at all. You have a different idea of what cams should do in a Harley, and it only reveals the choices we have. What you reference as a "fall-off at higher RPMs" isn't significant in my view. Looking at some charts, all 255's in stock TC96 engines seem to peak at around 5200 rpms and do decrease gradually between that point and the redline. It is significant to you because you venture into that range more than I do. I haven't exceeded 5000 rpms in probably a year and don't feel that I need to be there, as I have plenty of power on tap far below that for my needs.

That's fine, but you can't raise the entire range with any cam set in a stock engine. It's a trade-off, and if you cam for the top-end you'll lose at least something on the bottom and vice versa. The only way to have both is to at least increase compression.

Nobody's taking anything personally, certainly not me anyway. I'm simply discussing the topic at hand and giving my opinion. You don't need to suggest this every time we have a discussion about cams.

I don't need a recalibration because I'm satisfied with the way my bike runs. Recalibrate your own butt as you deem necessary.

I'm not sure what leads you to believe I'm offended, as you've suggested that in the past. I'm not, and if I was I would simply stop discussing these topics with you. I'm not even close to that point, as I do want to hear your POV.

 

That's simply untrue and points to a fundamental misperception about the way cams work. We're dealing with smog cams with an 8* negative overlap. That's so there will be no chance of any unburned fuel escaping with the spent gasses. Take our cams, keeping everything the same except tighten up the lobe centers, adding a little overlap, and you will absolutely see an increase across the entire rpm range. You will gain the benefit of exhaust scavenging. Our stock cams weren't designed for optimum performance. Aftermarket cams don't need to worry about EPA regs. Plug an Andrews 21 into a TC96 and you will get a modest improvement across the entire range. There's quite a few cams that will outperform the stock cams at every rpm setting, including the SE255s you have in your bike.

OF course, most aftermarket cam grinds aren't designed for a moderate gain across the entire band. Folks want the most performance they can get, so most aftermarket cams are designed to go in motors with other upgraded componants.


not sure I remember what threads you seem to be referring to here. You must be confusing me with someone else, as I don't recall suggesting you had taken offense to somethning I'd said. I for sure would remember that if it was, as you say, in all the cam threads we'd been involved in.

however, in this thread, I think it was during the part where you were telling me what I was thinking, and how I should give you a break, although you didn't exactly say who "us" was. That was what led me to think you might have taken some personal offense... I never suggested you were inexperienced or naive, but that was what you seemed to read into it.....

One thing I did say, and I will say again, is that if you think a bike with se255 cams pulls hard to redline, you should ride some other bikes sometime. Compared to stock cams, yes, they do. Compared to almost any other performance cam, not so much. And that was the only thing I was talking about in my original post. Not the performance of the cams in the lower third, which is exemplary.

My original discussion point was on the performance of the cams at the upper rpm range.....
at which point you started telling me I was missing the point because I wasn't talking about the lower rpm range....
so who was missing who's point again????

who in the world suggested you weren't satisfied in the way your bike runs? What does one have to do with the other?




we have certainly been guilty of hijacking a thread in the past as again here.
which seems to me to be a good point for me to bow out, as entertaining as this has been, I think we should spend a little time addressing the OP's questions......