If I was to stroke a 103 with 204 cams. Guessing that would kill the awesomeness of the 204? What would be the same cam in a bigger motor?

 

Do you mean stroking a 103 with a bigger bottom end or simply modding a 103. SE204 works well on oem 103 compression. If you want a similar cam with greater lift look at the cr575

 

The SE 211's will make you smile with a small bump in the compression.

 

I have seen quite a few guys use them on a 103. Some put the longer 1.75" rockers on them to get more lift.

 

I have 103 with se204s right now, for me the 204 in 103 is the ultimate combo. Should get a beefed up flywheel so was thinking stroker flywheel. But since the whole thing is apart anything could be done.

The 575 and other 57 types look great on the 110 dynos I looked at. Still not exactly like the 204. the 204 has flatter tq, though way less, and hp climbs to 5.8k. the 204 has a fat power band between 5k to 6k.

 

The extra lift of a diff cam or diff rocker arms does nothing unless you have head work done. Factory heads run out of air around 500 lift. Only of use if you are considering headwork in the future. If that's the case I wouldn't buy the SE204 cams and rocker arms. Just buy a cam that best suits your current and future circumstances.

 

Already tried the rocker arms. It was a waste. So is basically bigger than 103 a waste without heads?

 

Here's my take on things.
If you're gonna do heads get better cams. 204 cams will not take advantage of the extra air that headwork is intended to use.
If you're gonna do heads, perfect time while things are disassembled to go high comp pistons or go to 106 or 107 cylinders/pistons.
Or if you're happy with the 103 and 204 cams as is, which is a good and reliable Street combo, save your money and enjoy what you have. I've got a stock 103 with 204 cams, Supertrapp 2-1 pipe and a proper custom dyno tune and it runs well. Many people can improve their ride with a good pipe and tune

 

How do you know the 1.7 rockers was "waste"? Did you re-tune as you would have done if you had changed cams, which is what you did with the rockers? I have personally seen the difference between power in a 103" motor, stock heads, SE204 cams, with and without 1.7 rockers and there was an improvement. I hear those that say the added lift is not an improvement unless heads have been worked and do agree that headwork certainly makes a difference. However, while OEM head flow tails off at .500" lift, the head still flows but flattens out. If the intake valve stays open longer, which it will do with the 1.7 rockers, cylinder fill continues; more A/F in the cylinder = more power.

Having said that, if going from 103" to 107" I would be looking for a cam to replace the 204s; head work or not........

 

Sorry should have said a waste for me, didn't mean in general. For me any change has to be dyno tuned by someone competent. I did recently try out a pipe change without dyno, for one day.

The work of changing them and hauling the bike to dyno, I live remote. The cost of everything. The difference was slight. I should of did it at same time as changing cams, then why not do it.

I only did intake. Not sure if that's a problem. I got trusted advise to only do that.