SE 203 cams compared to Andrews 21N
 

I posted earlier that I had a set of SEH 203 cams. What I wanted to know is how close the 203's are to the Andrews 21N(my choice of cams I was going to order) Sorry for all the question's,my first year on a Davidson since 1977.(they have changed slightly :icon_lol: )

As you can see, they are similar. Both have advance ground into the profile; 3* on the intake/exhaust on the 21 and 1.8* on the intake and 2/3* on the exhaust on the 203. For a cam only upgrade on a TC88, the 21 woudl be my choice. The earlier intake close is going to boost corrected compression which will make more low end torque. If the bike is a dyan or a softail, I mignt go for the 203 just to save money but the 21 is still a better choice for your situaation IMHO.

I/O I/C Duration Olap LSA Lift
SE-203 18/36 42/17 234/239 35 100.8 0.510/0.483

TW21N 10/30 40/8 220/228 18 100 0.498/0.498

If you go with andrews or woods roller link conversion the 203s will not work. Those conversion kits require hybrid cams to work with the smaller inner cam bearings. Would have to be the N grinds from andrews or R grinds from woods.

I will just say it, the 203 is a POS! If you cruise a constant speed it feels like somebody is holding you back and letting you go and then holding you back... I love my TW 21! It is a wonderful cam and makes a huge improvement over stock even though the numbers don't look much different. Go with the TW21 but if you have to buy Harley then skip the 203 and go with the 204. It's much better! If you get a 4 degree key and a 204 you end up with a TW21. You can pull your heads and take a Dremel and take out the shelf below the valve seats. Basically remove the aluminum that sticks out from under the valve seat. Blend it in to the same diameter of the seat and you gain roughly 10 percent flow. This allows the TW21 to rev out rather well.