I'm planning on having my 96 bored to a 103 with high compression pistons. Cam will be the SE254, also have a thunderheader a heavy breather, stock heads. What can I expect in numbers? Keep in mind that SE is my only option as the dealer will honer my warranty with those parts, so 103 is a big as I can go.

 

My experience with these cams is limited to what I see at a local "dyno day" when guys bring their bikes to a local tuner (one of the best in the country) and, for $30, the bike goes on the dyno for a couple of pulls to see graph and numbers; no tuning.

What I have seen is that the 255 cams hit harder earlier and start to fade after 4000rpsm; 100TQ by 2800, peak torque between 3000-4000 rpms and not dropping below 100TQ until about 4200. The 254 cams don't have the torque off idle like the 255s; cross 100TQ about and not dropping below 100TQ until about 4500.

If looking for a touring motor, the 255 would be my choice; more torque early and not expecting much after 4500rpms. Both will put up similar peak numbers and neither will make much HP; they are EPA cams. My guess on numbers would be 85-90HP/100-105TQ with stock heads.

IMHO, I don't see the need for high compression pistons and 10.5 static is too high for the 255. Flat top pistons, 86cc chambers and stock head gasket puts static at about 9.8 but CCP is pushing 200psi. Not so with the 254s but when you say 10.5 CR, the high compression piston dome volume becomes important. You need to know what your actual chamber volume is and what the actual piston dome volume; some machine work may be required to actually hit 10.5 static.

Another benefit of the 255s; pretty much a bolt up build with flat top pistons but it would still be worthwhile knowing chamber volume.JMHO

EDIT: Food for thought. SE204 cams with 1.7 rockers, flat top pistons and stock heads. Different curve but you will see a bit more peak TQ and a lot more peak HP. Not a stump puller like the 255 but a nice build set up at about 9.8CR.

 

Found this video, puts out 100/117 with my planned setup.

 

I couldn't read the rpm range on the graph but it looked like the TQ was flat until near 3000 but, like I said, couldn't read the graph. Be careful looking at peak numbers, not the best choice for selecting a build combination. Rideability is much more important than peak number; you can't ride that dyno chart.

Not saying you would not like the combination but just suggesting that you talk to some that run the 254s and with what complimenting parts. The tune is so important for rideability so finding a good tuner is as important as the build.

 

I believe you will be very happy with that, know of someone running the same set-up on a 103 and they are very happy with it, the bike hauls azz. Who gives a turd or whatever if a Woods cam or some other brand might make 5 more horsepower, SE cams are just as good as any other cam out there.

 

You need to compare cam profiles. SE cams are profiled to meet EPA requirements and not nearly as good as aftermarket cams for that reason. Everyone is entitled to an opinion but facts are pesky; they are facts supported by data, not opinions. But don't take my word for it, ask any professional builder/tuner.

 

It takes several components and a good tuner to create a quality torque curve. It's not just in the cam.. but if you want to run that compression talk to your builder about the SE 251 or 259. I think you'll like that a little better.

 

If you are going to jack your compression to 10.5:1 and sticking
to SE cams the 259E cams will be your best choice, that is my opinion.

 

So how did this work out for you?

I've got the 254e in my 2013 FLHX which has V&H power duals and Ventilator intake. Stock top-end. I'm thinking of installing a 107 with 10:1 pistons.

It is a similar setup to the video link and it produced some pretty good numbers from bottom to top.

Anyone else with a similar setup?

 

I have put the build on a hold as for now, as I am not able ride now due to a stroke. But leaning more towards keeping it a 96" and putting in the se 204's as for the killer idle