SE255 Cams
Road Master
Joined: May 2010
Posts: 1,005
Likes: 4
From: Alabama
I respectfully disagree.....My bike is not "dead" after 4000 rpms. The SE255's will not pull quite as hard as "bigger" cams above 4000 rpms, but it surely is not "dead".
I do not race my bike. However, I have once ridden next to a stock cammed 96, a friend of mine riding solo on his 2010 Ultra Classic. This was right after my SE255 install. I was riding two up, he got froggy at a red light and we pulled right past him. He had no idea I had installed the cams and was floored that we rode past him with us being two up. So no, they are not dead even to stock cams.
The SE255's are not "race cams", but for all around performance on a heavy touring bike they perform great.
Road Captain
Joined: May 2011
Posts: 745
Likes: 0
From: Sacramento
not disputing the 255 cam in a 96" now that said my dyno guy ran the numbers on the cams & told me the 255s are not a good cam for the 96" they are designed more for the 103 & higher compression.
i would like to do cams & was tossed up between the 204 & 255.
maybe some of the dyno guys could explain.
my style of ridding would I think the 255 would be a better cam.
sorry to hijack
i would like to do cams & was tossed up between the 204 & 255.
maybe some of the dyno guys could explain.
my style of ridding would I think the 255 would be a better cam.
sorry to hijack
Road Warrior
Joined: Jun 2012
Posts: 1,672
Likes: 17
From: Orange, VA,
I was in the same boat so I did a lot of looking and comparing, a friends bike had SE 255's and another had SE 204's, there were others I tried as well, I finally decided on the Se 204's, performance, idle sound, they were in my opinion the best ones.
Ultimate HDF Member
Joined: Feb 2012
Posts: 7,855
Likes: 11
From: Oroville,Washington.
Have the 255's in a '10 RK. 103 motor with big air,Freedom Performance mufflers,SE Pro tuner. 46 mpg all day at 75 mph. Do a lot of mountain riding,up and down through the gears,and the torque those cams put out is exceptional for that type of riding. Don't buy that crap about "running out of power at 4 grand, I'm at 120 mph outa' 4th gear,with 2 left,and have yet to see any fall off in the high rpm range,simply doesn't happen.
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
I also disagree, but it's all relative. The 255's provide more peak HP than stock cams, usually along the lines of 5% or so, but it is also true that the top-end is outside their sweet spot and most other aftermarket cams perform better there. Therefore in that context I will agree with Coolhawg6622 that most other performance cams on the market will provide a better kick above the midrange, but it's all in where you want the power. If you want to race the bike SE255's are clearly not the cam you would want to install, but for real-world riding on a heavy, tall-geared touring bike it is hard to fault them in any practical context.
Remember that you can get both low-end torque and performance in the top-end by making other more invasive changes--like bumping compression and displacement, etc.--but we're talking about bolt-in cams for stock (Stage 1) engines. You can have it all by modifying more areas, but most of us don't want to do that. What's certain is that if you aren't careful and select the wrong cam for a stock engine the low-end will suffer, giving you flat performance there where you may want and need it in practical use.
I would venture to say that most will find that up to 4000 rpm is strong enough with 255's that you won't want or need to go higher a majority of the time, and IMO the priority is having the power where we ride most. All that said, I believe that "run out of steam above 4000 rpm" is not the sensation I get with my bike. I feel a good pull all the way to the red line, without pronounced peaks or valleys, and "the band" is truly the entire RPM range.
Remember that you can get both low-end torque and performance in the top-end by making other more invasive changes--like bumping compression and displacement, etc.--but we're talking about bolt-in cams for stock (Stage 1) engines. You can have it all by modifying more areas, but most of us don't want to do that. What's certain is that if you aren't careful and select the wrong cam for a stock engine the low-end will suffer, giving you flat performance there where you may want and need it in practical use.
I would venture to say that most will find that up to 4000 rpm is strong enough with 255's that you won't want or need to go higher a majority of the time, and IMO the priority is having the power where we ride most. All that said, I believe that "run out of steam above 4000 rpm" is not the sensation I get with my bike. I feel a good pull all the way to the red line, without pronounced peaks or valleys, and "the band" is truly the entire RPM range.
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
I would like to do cams & was tossed up between the 204 & 255.
maybe some of the dyno guys could explain. My style of ridding would I think the 255 would be a better cam.
maybe some of the dyno guys could explain. My style of ridding would I think the 255 would be a better cam.
Stock cams have an intake close of 30° and 204's are 34°, so you aren't too far from stock with those. Add some compression to the 96" (e.g., shave the heads and/or use a thinner gasket to get compression to 9.5-10:1) and it's a different kettle of fish altogether, but many of us simply want a nice performance bump without disassembling half the engine in the process.
Because of the relatively low compression (9.2:1) in stock 96" engines, IMO there are only several good cam options if you don't want to make more invasive changes and don't want to deplete low-end performance. The SE255, Andrews 48H, and S&S 551 "Easy Start" would be on the top of my short list for a 96" engine. In a 103 there are more options, and for that motor I would include the Wood 222 and SE204, among others, to that short list.
Road Captain
Joined: May 2011
Posts: 745
Likes: 0
From: Sacramento
Your "dyno guy" needs to become more informed about these cams. They have a very early intake close (25°), which is the key to the improvement in low-end grunt, and they do very well in an otherwise stock 96" engine. CCP for the 96/255 is 185 psi, but in a 103/255 it increases to 203 psi, which is at or slightly above the maximum some feel is best. Higher may cause starting problems, although late-model factory 103's have ACR's, which should nix that problem altogether. HD states that maximum compression for the SE255 is 10:1, which is the spec for a Stage II 103 and arguably factory 103's--so to say they do well in a build with even higher compression is IMO bad advice. He may be talking about the 254e or any of the other SE cams, and if so I would agree.
If you place a high value on top-end performance and don't mind losing a bit on the low-end I think the 204's would do well for you. OTOH if you want to increase power down low through the midrange, with peak-HP improving only modestly, IMO the 255's would be the best choice.
Stock cams have an intake close of 30° and 204's are 34°, so you aren't too far from stock with those. Add some compression to the 96" (e.g., shave the heads and/or use a thinner gasket to get compression to 9.5-10:1) and it's a different kettle of fish altogether, but many of us simply want a nice performance bump without disassembling half the engine in the process.
Because of the relatively low compression (9.2:1) in stock 96" engines, IMO there are only several good cam options if you don't want to make more invasive changes and don't want to deplete low-end performance. The SE255, Andrews 48H, and S&S 551 "Easy Start" would be on the top of my short list for a 96" engine. In a 103 there are more options, and for that motor I would include the Wood 222 and SE204, among others, to that short list.
If you place a high value on top-end performance and don't mind losing a bit on the low-end I think the 204's would do well for you. OTOH if you want to increase power down low through the midrange, with peak-HP improving only modestly, IMO the 255's would be the best choice.
Stock cams have an intake close of 30° and 204's are 34°, so you aren't too far from stock with those. Add some compression to the 96" (e.g., shave the heads and/or use a thinner gasket to get compression to 9.5-10:1) and it's a different kettle of fish altogether, but many of us simply want a nice performance bump without disassembling half the engine in the process.
Because of the relatively low compression (9.2:1) in stock 96" engines, IMO there are only several good cam options if you don't want to make more invasive changes and don't want to deplete low-end performance. The SE255, Andrews 48H, and S&S 551 "Easy Start" would be on the top of my short list for a 96" engine. In a 103 there are more options, and for that motor I would include the Wood 222 and SE204, among others, to that short list.
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Stellar HDF Member
Joined: May 2008
Posts: 2,588
Likes: 9
From: Sunny Southern California
Banned
Joined: Feb 2010
Posts: 1,910
Likes: 263
Have the 255's in a '10 RK. 103 motor with big air,Freedom Performance mufflers,SE Pro tuner. 46 mpg all day at 75 mph. Do a lot of mountain riding,up and down through the gears,and the torque those cams put out is exceptional for that type of riding. Don't buy that crap about "running out of power at 4 grand, I'm at 120 mph outa' 4th gear,with 2 left,and have yet to see any fall off in the high rpm range,simply doesn't happen.
