What is the differnece between the SE-203 and SE-204 cams for the 88?

It looks like the 204 has higher intake and exhaust lift and the intake opens a little quicker (34 compared to 36 degrees) on the 204, which should mean a little better low end....
Both can work with stoke valve train.

What is the REAL world difference between the 2? anyone know?

 

I believe both are 510 lift with the difference being the intake and exhaust duration. I had a set of 203's in my bike and was definitely not impressed with them. I know of a few people who run the 204's and they seem to pull harder and longer than the 203's.

 

SE-203 18/36 42/17 234/239 99/103 100.8 .510 .483 .178 .152

SE-204 22/34 52/8 236/240 96/112 104.0 .508 .500 .208 .129


Obvious differences are intake close, duration, lobe centerline, LSA and TDC lift. Not so obvious is the ground in advance. SE203 has 1.8*/2.3* advance ground into intake and exhaust respectively and SE204 is 8*/8*.

Real world differences are, from my lmited experience, is that the 204 will make more TQ under the curve and move the curve farther right than the 203. In other words, the 203 starts making power earlier than the 204 but doesn't make as much peak and doesn't make it as long. The 203 works better in the heavier touring bike and the204 works better in the dyna and FL softails. The both need some compression to really work well but with the ground in advance they are prone to detonation. Static compression for either should probalby not exceed 9.6. The 204 is capable of making over 100TQ and mid 90s HP but if you live where the summers are hot, like south Texas, Arizona, Nevada, etc. you just have to be careful how you set them up.

 

I've tried the 204s (a few years ago) and my brother tried the 203s. We both thought they were pretty much a waste of money. Not much of an improvement over stock for the money. If ya gotta go SE, then maybe the 211s or 257s would be better. We both went to S&S gear drives and love'em.

 

yeah, I've heard this about the SE-203 but don't know anyone that has installed the SE-204.

I have an 88 with SE air intake, V&H slip-ons and a PCIII. Thinking of upgrading the cams next and will proably go gear drive, but I think this won't do much w/o head work or new heads. Would like to find a head/cam set to get the most out of the 88.

I have more experience building v8's but any internal combustion engine is just an air pump...the more air moved in and out - the more power. Cams may help to a point, but without the heads working with the cam...you can only expect so much improvement.

Now, maybe the stocks heads will work great with a certain cam or 2 or maybe there is something about the twin...I don't know. I am only at the "gather info" stage so any info is appreciated.

 

Is there any way to tell if an aftermarket cam has been installed in your bike? My bike sounds like there might be a cam in there but not a crazy one...maybe the SE 204?...my mechanic and the dealer i bought it from both think there might be something. I bought my 08 street bob with pipes and se air cleaner and harley tune, hmmm....

 

The SE204 is an underrated cam and most of the guys that trash the cam have never run one or, if they did, didn't set it up right.

I ran the 204 in a 95" configured Deuce, stock heads, .030" head gasket, V&H Sideshots, SERT tuned to 91TQ/85HP; not a barn burner but the bike ran very well with no detonation issues.

I had BigBoyz street port the heads, retained stock valves, inreased compression and, once retuned, the engine made 103TQ/93HP. Pulled to the rev limiter and was hell on back tires. The 204 with the ground in advance has a very lopey idle, much like a small block chevy with the old Duntov cams. I did have some pinging issues later in the season when south Texas heated up in July and August and I had to change cams to elimnate the detonation. We pulled timing out but that caused the bike to lose power and run sluggish. I had increased compression just a tad over what south Texas heat and corn fuel can accomodate without some ping; my bad.

Don't underestimate the 204; if set up properly, it is fun cam. I wouldn't install it in a touring bike but in an FX or an FL softail, wouldn't hesitate.

 

Not in a tourng bike? Why is this? Low end lacking?

 

Yes. If the only two cam choices for a touring model were the 203 or 204, I would run the 203. However, there are aftermarket choices that will out perform the 203. The 204 will perform as well as some aftermarket choices, so, IMHO it is worthy of consideration for one of the "lighter" models like the FXs and FLSTs.