Hi all, I hope some of you have better weather than we do right now. I am curious about all of the cam talk that goes on, most people dog the SE 255 cams because they run out of steam early, and I agree they do. I just finished my 103 with 255's and they pull hard from idle to 4500 which is where I ride most, but I know other cams will out power the 255's from around 2800-3000 to redline. What I would like to have is a cam equal to the 255's in TQ from idle to 2800 but make more power from there on up, is there such a cam?? I know someones going to say you're lugging the bike below 2500, well I guess I am because I ride alot in the 2100 to 2600 rpm range around here on 2 lane roads and with the 255 cams my bike is very smooth at the low rpms, it doesn't seem to lug until below 2100.

 

I can not help ya with your request.
However, at 4,500 rpm's you are doing some serious mph. At 2,900 rpm on my Ultra I am running 80 mph in 6th. I like the SE 255 cams. I have another bike if I want to play. My Ultra is for cruising and touring.

 

Sorry, but you can have it one way or the other but not both. You can either have lots of off idle torque or you can have lot's of mid to high with a nice rev-out. I prefer the latter, personally, but there's nothing wrong with either - you do have to choose though. I've run both types of cams riding 2-up and haven't had any issues with either. Lot's of fun to rev that baby out, though.

 

I know that you can't have the best of both worlds, but I was wondering if some of the cams like the Woods 5-6 or andrews 21 or 26 or some other cams have as good of bottom end tq as the 255's. I feel like a cam with the same bottom end might still out do the 255's on up in the powerband due to their designs. I'm curious because everytime there's a post about the 255's the first thing somebody says is how many better cams there are, why would you want the 255's, brand X cams make so much more power than 255's, where are the cams that perform with the 255's up to 2800? I'd give another cam a try just to see, I just don't know where to start.

 

My final four choices were SE 255s, SE 204s, Andrews 31Hs and and Andrews 37Hs. Both Andrews' cams have the lift and duration, but the event timing for intake and exhaust are different. The SE 204s have basically the same lift and duration and the 37Hs but different timing events. The event timing of the intake and exhaust is a major contributor the the cam's powerband. So I could vary the powerband with the same basic cam if I choose the 204s, 31Hs or the 37Hs. Looking at the timing events, I thought that the 204s fell in between the 31Hs and the 37Hs but closer to the 37Hs. In the end I choice the 204s based mainly on price. My second choice was to be the 37Hs.

I thought that the 255s would be perfect if you never go above 3600rpm. I don't do that frequently (yet), but I did not want to limit myself either in the long run. I may lose a bit below 2000rpm with the 204s, but probably not enough to really know it. Harley says the 204s are good from 2100-5800rpm. Seems OK to me.

I think the 31Hs may give you a bit more on top over the 255s without losing any noticeable bottom end. Andrew says the 31Hs have a powerband from 2000-5000rpm. How much more? Difficult to say. Is it worth cost? Not to me.

As was stated above, you can not have the best of both worlds without variable valve timing. So you have an opportunity for some R&D with the cams, or you may choose to tweak your tune for the 255s. Personally I would enjoy the R&D part!

 

Go to www.zippersperformance.com. These guys know their stuff when it comes to v twin cams. Sounds like you might need the redshift 575tc cam.

 

I would like to see how a Woods 5-6 with a 2* advance would work.
Best calculations I can come up with is about 95 lbtq @ 2500 peek around 115 tq @ 3500, about 105 hp? I crunched these #s 3X and it seem realistic. Anyone else?

 

Peak numbers are only good for dynos. In real world riding, it is the area under the curve that matters the most. Here is an example: If the peak number dyno curve rises and falls very quickly (much like an inverted "V"), then the majority of the available power is in a very small rpm range when compared with a smooth, steady dyno line over the entire rpm range. Yes, the peak number may be 8HP greater than the maximum steady number dyno run, but the other results from the peak number curve will be much lower (may be 10-15HP less) than the smooth, steady dyno curve over the remaining rpm range. This is obviously an extreme example, but it helps to demonstrate the point. Thanks.

 

I agree with your analogy and I personally like bikes with broad torque bands. The calculations I came up with puts the peek HP @ 5500 which would put torque @ 5252 around 100 lb. I honestly thing my calculator might be a little ambitious by about 5%. mid through top end.

 

I am happy with how smooth my bike is with the 255's, I just wonder if there could be a little more to be got without going overkill. I have a good tq line and I think a good 2 into 1 exhaust would get a little more out of the build for me.