103ci SE ST Legal Big Bore upgrade

[fxr_george]

ORIGINAL: davlyo The Stage I kit increases the Bore from 96ci to 103ci. The Stage II kit increases the Bore the same amount but adds the SE 255 Cam kit (25638-07). What does the Cam kit add to my performance upgrade? I have always been told that inches are important -or -size matters. But the Cam kit isn't adding inches or size -so what does it add to the performance? I will do some looking at different cams for the stage II 103 kit. I was gonna go with the se 110 kit but I do not trust the stealership to split and bore cases without a cnc machine. The stealership said they would let me put a hotter set of cams at the bike when they put the 103 kit in it. I will do more reading and ask questions and post back. With that in mind any guys running a 103 and what cams go you have in it.

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[fxr_george]

Here is what www.nightrider.com recomends for touring bikes as far as cams go.
Andrews TW-26H
Crane HTC-300
Kuryakyn TC-1
Andrews TW-37H
Crane HTC-310
Red Shift 575

[nidan]

I have the 103 Stage II /SERT with SE 4" slipons.
While I'd agree there are better cams , the 255 isn't that bad . After break in , I'm pleasently surprised. Yes there are hotter cams , even in the SE stable,but not that maintain warranty.

I've got many friends with 103's ( 100+ in my group) the most popular cam setups are the Zippers Redshifts , and Freedoms .


I'm leaning towards the 32H as I had the 31G ( lower lift version .510 vs .570) in my 95" and got 98hp /101 lbs ft with heads/ SE Slipons and it pulled hard from idle . Andrews claims a 20% power increase for the 32 vs 31. With the bump to 103(8% displacement) roughly 127hp, 130 lbs ft with similar headwork., that is in line with most of the .570 lift cams with good builds.

100+ lbs from 2200 up is a reason to smile

[Black Flag]

dav.
Stage II with 255's works well for me. I suppose a 2 into1 header would get me into the 100/100 club, but I'm not complaining. Good luck with your build!

[fxr_george]

I shot out an email to www.nightrider.com and asked what SE cams would he use. Keep in mind the dealer is letting put a bigger set of cams then the SE255 cams that come with the SE103 kit. Here is what he suggested.

I like the SE-251 cam. Greatly under-rated by most HD Dealers, this is a very solid performing cam that does have the potential for a broad flat torque curve and somestrong HP in the upper range. This is also a cam that is ideally suited for the mild 9.5:1 compression ratios that should be run on FLH based bikes to prevent detonation and serious overheating above/beyond the normal high temps HD engines experience. Do not confuse mild compression with low power. Good aftermarket shops can get 110-115HP from 95/96/103 engines with this lower compression.[/align]

[Boxer Harley]

I did this kit to my 07 SG, with Rinehart 2-1, SERT, Super Sucker. If I did it all again, for about $250.00 I could have had the heads done while the bike was tore down.

Three words DO THE HEADS.

I would also change the head gasket to bump the compression.

[fxr_george]

ORIGINAL: Boxer Harley

I did this kit to my 07 SG, with Rinehart 2-1, SERT, Super Sucker. If I did it all again, for about $250.00 I could have had the heads done while the bike was tore down.

Three words DO THE HEADS.

I would also change the head gasket to bump the compression.

While the SE cylinder heads can produce nice improvements in performance, Nightrider recommend the use of professionally ported heads from the aftermarket to maximize power capability. The top rated performance shops are constantly refining their product to improve power output. The best performance shops are able to get 100+HP and 100+ft.lb. torque from 95/96 cubic inch engines with 9.5:1 compression. This would translate to 110/110 from a 103CID engine and 120/120 from a 110CID.

9.5:1 compression ratio is recommend to prevent detonation and overheating that frequently occurs in the heavy FLH based bikes. A properly built 9.5:1 engine makes about 97% of the power of the higher compression engines.

I will stick with this advice and one more I really think I would spend more then $250 on a head job, always cost me more if a girl gave me one in the end.

I am just trying to keep a warrenty for two years and still have fun.

[MikeBarn]

a

[Jim Dawson]

I'm perfectly happy with my 103" and SE255 cams. If I really wanted a hot rod I wouldn't have bought an Ultra.

[jimmyroadking]

well said!