performance
Tourer
Joined: Jan 2011
Posts: 290
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From: wayland ny
The S.E. 255's are supposed to be a good cam that produces good power in the 2-4500 rpm range. There's also the S&S 583's or the Andrews 55h's. All three produce similar power and are good to use in your 103" motor
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Joined: Dec 2007
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Another great option would be a Wood TW-5-6.
Scott
Intermediate
Joined: Nov 2011
Posts: 33
Likes: 4
From: Beaumont
I am also researching cams for my 103 and was considering the SE 255 as the advertised "usually shifts below 4500" applies to me. The question I have is what you meant in your comment of upside down and inside out?
HDF Community Team
Joined: Jun 2006
Posts: 12,763
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From: san antonio
Scott can speak for himself but IMHO, the 48 would be a better choice for a cam only upgrade than the 255. Same bottom end but with the added benefit of more on the top end. The 255 starts to fade above 4000rpms. If only interested in low end power, the 255 is not a bad choice. Often referred to as a "school bus" cam; plenty of TQ but not much HP.
Last edited by djl; Jul 11, 2012 at 01:20 PM.
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As djl, pointed out, the 48 would be a very good choice indeed.
Scott
Intermediate
Joined: Nov 2011
Posts: 33
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From: Beaumont
I have been looking at the specs for the Andrews 48H and comparing it to the SE 255. The lobe centerline angles that I calculated from timing chart in the SE catalog are similar for the intake and only 3.5 degrees different for the exhaust However the duration is longer so the 48 intake opening is advanced compared to the 255 and the exhaust timing is also. The problem is that although I can clearly see the differances in these two cams I usually don't know exactly what it all means to me and getting what I want out of my bike. Can anyone point me in the direction of some good information on the effects of cam specs and mating them to intake, displacement and exhaust?
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From: deland,florida
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HDF Community Team
Joined: Jun 2006
Posts: 12,763
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From: san antonio
I have been looking at the specs for the Andrews 48H and comparing it to the SE 255. The lobe centerline angles that I calculated from timing chart in the SE catalog are similar for the intake and only 3.5 degrees different for the exhaust However the duration is longer so the 48 intake opening is advanced compared to the 255 and the exhaust timing is also. The problem is that although I can clearly see the differances in these two cams I usually don't know exactly what it all means to me and getting what I want out of my bike. Can anyone point me in the direction of some good information on the effects of cam specs and mating them to intake, displacement and exhaust?
Remember your OP which was pointed at a cam only upgrade. Either of the cam mentioned are good performers; just different.
Intermediate
Joined: Nov 2011
Posts: 33
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From: Beaumont
You can study lobe center lines/angel, LSA, duration, etc. until your head explodes. Better time spent studying dyno charts and hearing from guys that have installed a particular cam. At the end of the day, you can do all that but until the cams are installed and the engine tuned, you really won't know whether you like the cams or not.
Remember your OP which was pointed at a cam only upgrade. Either of the cam mentioned are good performers; just different.
Remember your OP which was pointed at a cam only upgrade. Either of the cam mentioned are good performers; just different.