103"/Se204 Charts ?
103"/Se204 Charts ?
Anyone recall seeing any dyno charts/info on 103" builds using the SE204 cams. Some say the compression of the 103" is too high (10:1 ?) I'd like to see some to see how they compare to the 255. Just curious....
I'd love to see the 204's with the 4 degree advance in a 103 with a 2-1 exhaust. I think that would be a very entertaining ride. I thought the 103 as used in the ultra limited is something like 9.7:1. Either way, I don't see how it could be too high compression.
Nope, it isn't. The local builder here says that the SE204 would be fine up to about 10.5:1 I might think that a 4* with this cam on a 103" might cause detonation problems ?
Last edited by troop; Mar 12, 2010 at 04:47 PM.
103 Build w/ the SE204
I just finished a 103 build w/ a set of SE204's for my trike, did a lot of research before I settled on the 204's over Woods, Headquarters, etc. I used flat-tops which, with Harley's head gaskets supplied with their kit comes to 10 to 1. The manager of the local Harley shop has done a lot of these with good results (the 204 has a 4 degree intake advance over most cams and builds static compression on its own, so you don't need or want to run them at high compression as you may end up with preignition). I added 1.725 rockers to increase the overall lift from .508 to .539 for a bit more torque. I'm using this motor in my 1200 pound trike, so I need low end torque and a good midrange hit, and the 204's are great for this. With stock heads and intake (no high flow injectors), you'll start running out of air around 4800rpm. Porting and maybe a Kury 57mm intake and injectors might help here as 204's make power clear to 5800, but there's other cams out there for high end power. Keep it a simple build and you'll love the SE204's. I know a guy that did the same 103" kit, SE204's, crappy pipes and an SE aircleaner and got 99hp/110 torque, everything else stock. It's THE cam for budget builds. See the 103" build in my signature. Kury, Hi-flow injectors, Sachs heads (big valves, great porting, milled), 2 into 1 FatCat, and a costly Dyno Tune. That extra 13HP cost me about $300 per Hp. We're tuning my latest 103 now, I'll post numbers after I get some break in miles on it. The last build went straight to the Dyno after build and a few town miles at 98 degrees, torture! Good luck, I'd like to see how your build turns out. And fit an oil cooler into your budget, $200 well spent. 
Here's a quote from a guy that knows his cams (hope this is proper etiquette):
To quote George C:
"If you look at the cam charts, the SE 204 is almost exactly the same cam as the Andrews 37B, with the difference being the 4 degree advance with the 204. The reason the 204 is so effective is the cam raises the static compression with the advanced degree. Tons of power everywhere when mated to a 9.4 to 1 ratio. It's the perfect cam for a 95" build. Add head work and you will be very impressed. Your numbers will come very close to the magic 100/100 with the right head work, and the power will be stout across the entire RPM band. Do NOT use high compression pistions with the 204. It will give you too much static compression and may result in uncontrollable pre-ignition".
Here's a quote from a guy that knows his cams (hope this is proper etiquette):
To quote George C:
"If you look at the cam charts, the SE 204 is almost exactly the same cam as the Andrews 37B, with the difference being the 4 degree advance with the 204. The reason the 204 is so effective is the cam raises the static compression with the advanced degree. Tons of power everywhere when mated to a 9.4 to 1 ratio. It's the perfect cam for a 95" build. Add head work and you will be very impressed. Your numbers will come very close to the magic 100/100 with the right head work, and the power will be stout across the entire RPM band. Do NOT use high compression pistions with the 204. It will give you too much static compression and may result in uncontrollable pre-ignition".
I probably have worn out my cam welcome and to many I have to say " I'm sorry for being a bit abrupt (Brian)". I gotta tell ya, cams/head volumes/etc are a lot to take in for just a bolt on parts kind of guy and my lack of "getting it" is my downfall !! I did some Big Boyz calculations plugging in 204's for my 103" plan (local dealer gives 20% off if I'd go that route), entering 103" SE flat tops/stock heads/.045 hg at 1050' = 9.85:1 static/9.29 corrected and 187ccp. Punching in Cometic steel .051's yields 9.74/9.19/184ccp but I'm sure somehow, this probably wouldn't be the way to go? Do these sound about right for the profiles of the 204 ? Remember, I don't plan on headwork.
Last edited by troop; Mar 14, 2010 at 05:08 PM.
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From: upstate ny
103
Just has a 103 stage iv done cant wait to get dyno sheet printed! dealer said after 1000 miles we will dyno it seems to think it will be near 110 hp with close torque numbers hope im not disapointed! yes i put auto compression releases on, cant wait to ride it!
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From: down south
Troop, I don't think you'll have any probs with the SE-204 in the 103". I'd do the SE 1.725 rockers along with a mild head port. That's the route that I'll probably take once I get some more $$$$. The SE-204 is really an under-rated cam and you don't hear about it too much. It's just not the "flavor of the month cam" on any of the forums and it probably never will be! I'm happy in my decision with the 204 cam.
Last edited by fripple; Mar 15, 2010 at 09:22 AM.
Road Master
Joined: Dec 2009
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From: Sacramento
I've got the 204's in my 07 with 96 inches and I'm very happy with the way it runs. It has at least stock levels of low end up to 2500 (actually feels like more) and from there on up, big bonus. It doesn't really flatten out until after 5 grand. Lots of fun. Stock clutch with the easy pull spring is iffy but I'm deliberate with my clutch use. I swapped primary fluid from 10/40 amsoil to royal purple atf which seemed to help the clutch a bit. I went with this cam knowing that down the road I'll have other work done such as mild porting and 103 or maybe S&S's 106 kit. Haven't made my mind up on which way I'll go. Having fun with the way it is right now.