And I never said that. I have been saying you can compare charts from similar builds with different cams to come to a conclusion about the differences in the performance characteristics of the cams. Seems that others don't agree on that point which is fine by me; end of discussion; we just don't agree.

 

What cams do you recommend for the 103? Been using the 255s for a couple years to keep my warranty but now that it's finished I'm open to other options. Lots of people are saying that the 255s are strong from the bottom but I find they don't start pulling hard till I hit 4,000 rpm and beyond. I would like more power everywhere on the rpm scale.

 

No, you didn't, Iclick did. Keep up

 

With those cams, if you don't feel like your bike is strong off idle, you might need another look at your tune.

There's two or three cams that have come out in the last few years that have been getting good results in the 103 bikes. The CR575 is an obvious choice, and as of about 6 months ago probably would have been on the top of my list. We took down a friends stage II 103 with the 255 cams at the end of the summer, and re-built it with the 575 cams. It's not been on a dyno, but after a few v-tunes, it already feels stronger across the board than it did with the 255s. No significant other changes to the bike, we re-ringed the pistons, and bolted it back together with SE head gaskets.

I had the SE204/1.725 rocker combination in my own bike, which had a great throttle response right off idle, and I'd have no problem building the same motor again. I've noticed a number of other bikes on the forums lately with the same combination.

What I'd really like to try next with a 103 is try the Tman 600SM cams. I was chatting with one of the local head porters, and he feels the tman cams will be everything the CR575 cams are and more. I couldn't say for sure, but I'd like to find out. 240 duration, 600 lift, and only .198 lift at TDC, so no clearance problems with your cast flat tops. It seems like a lot of lift for the stock beehives, but we know the beehives can handle that much without going into coil bind, and if the lobes are drawn correctly, and the transitions aren't too radical, there should be plenty of spring to control the valve as it returns to the seat. That would be a cam that would work well in a 103, but you could go bigger with it as well.

Two other good cams for the 103 bikes are the tw5 and the Andrews 37.

There are lots of good cams out there. So many good cams, that they start to run together a bit. The good news is that it's easy to build more power than the stock bikes came with.

 

Thanks for the good info. My feeling of my RK not being so strong off idle is probably relative as my other two bikes will yank my arms hard and power wheelie at the drop of a dime in first, but then they're much lighter. I wouldn't mind being able to burn rubber on corner exits with the RK though...

 

There are lots of good cams.But remember,those high lift cams will accelerate valvetrain wear.You can get some good power out of the HQ 500,andrews 37 and the SE204. A smaller cam and lowering your gearing will feel just as good,maybe better.

 

You quoted me, so I thought you were referring to something I said. Maybe we do agree.

I am liking the TMan 600SM as well. Planning an upgrade of my 95" Deuce next year, not sure if I will just go to 98" or case bore and go 104"/107" or 113"/117". If I go bigger than 98", I have to case bore and once that far might as well install a Hobanized 4.375" crank. Then it a choice of useing the MTC 4.125" cylinders I have or the OEM 4.060" cylinders. Leaning toward 113"; looks like the best bang for the buck on paper. I like the 4.060" cylinders with CP pistons. Just in the incubation stages now; maybe there will be a 120R crate motor option for the early softails in the future? :icon_grin:

 

Interesting about the CR575 cams, do you feel that they pull better than the SE 255 in the 2000 rpm range? My Limited isn't used as a race bike, I couldn't care whether someone can outrun me. It is used as a two up touring bike, with a lot of mountain road riding, since we live in the Appalachians. I installed SE 255 because with the stock cams on roads like the Blue Ridge Parkway with it's 50 mph speed limit I was constantly having to shift down to forth and sometimes third on a lot of steeper uphill curves. 50 on my bike puts you at around 2200-2300 rpm in fifth, with the 255s there is enough extra power over the stock cams that as the speed bleeds off on a steep uphill curves where you have to drop a little below 50, you can roll the throttle on and maintain speed without having to downshift, at least most of the time. We went to the Keys in October, coming back we had reasons to get home a little qiicker than usual, so we rode the Interstate, something we usually don't do. I found that with the 255s the bike accerated much better in sixth at 75-80 mph than it did with the stock cams. If the CR575s can do better than the Se255 down in the low 2000 range and still beat them at 4000 thousand and up, I'm at least interested.

 

I might indeed pick the 48H if I were doing it all over again, especially if it was going in a 103. OTOH, I rarely feel the need to exceed 4k RPM for any practical purpose, so I doubt if I'd notice much difference in my present situation. You can pick up 255's for $150 on the used market and the cheapest I think you'll find the 48H's is $250 (new)--and being frugal by nature that would factor into my decision too.

Yeah, he is talented for sure. I've seen a few other charts for a TC96/255 not produced by Herko that hit the 100-ft/lbs line.

They are always on my list of recommended cams for a stock 96 or 103, and I agree that they are very appealing. As for drag racing, I would think most any performance cams would beat 255's in that environment, as they are clearly not designed for maximizing peak-HP, and that's where you'll be going through the gears in a drag race. If drag-racing is a high priority I would probably leave both cams off the list, as well as the S&S 551, but even the 255's produce more peak-HP (~5%) than stock cams with all other factors being equal. Thus, it isn't as if you're losing performance above 4k RPM.

I've collected maybe a half-dozen charts, most hitting the 100-ft/lb line on the TQ chart, and I think like everything else this depends on ambient conditions and tune. Someone on HTT once remarked that the 255's were "the most talked-about cams on the internet," and I don't doubt it if you restrict the field to baggers. There is some negativity among some, calling them the "school-bus cams," etc.--but I think it's safe to say that there is much more feedback that is positive. I think most who denigrate them have only looked at HP charts and have never ridden a bike with them installed.

 

I know how you feel and I was just returning your good-natured ribbing. I think we basically agree on most of these cam issues, for the most part anyway, but as discussed in the past we have a different set of priorities in what we like for our own applications. Basically, I'm reluctant to tear-into a good-running engine that IMO only needed a little more oomph to get it where I wanted, and the Stage 1 setup with stock cams was really quite adequate for me. You see I came from a '96 RK Evo with EV13 cam and no other engine mods, which was fine for me, so even the Stage 1 SG was a tier or two above what I had.

You relish being able to out-run your friends and I appreciate that competitive spirit, but I just don't have it. None of my friends seem interested in sparring, so it's not like I'm challenged very often anyway, and if I got beat it wouldn't bother me at all. It's all relative to one's expectations and desires. OTOH, if I was out-run but a stock SG I might take a look at some things.

[/babble]

That's a fair statement and I would like to see the numbers on my setup too, but it probably ain't going to happen. You see, I don't care what the numbers are, as I know how the bike ran with stock cams and how it runs now, and that upgrade has met my expectations. That's all the gratification I need.

No doubt on all those points, but DJL showed us what is probably the worst 255 chart I've seen and I posted the best, with maybe six others in between, so I think it safe to assume that one might expect to be somewhere between those two extremes given a good tune. That was my only point and I hope I represented the chart as such, not as something one might necessarily expect to achieve.