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[snowrider13]

Helping a friend out looking for info for him. Can anyone tell me what cam was used in a 2003 CVO Road King from the factory? Also what would be the upper limits for valve lift with the SE 103 heads of that year. Thanks in advance.

[SHRADER]

The stock cam in all CVO 103 bikes was the SE253 cam.

You might try to search this cam to find out more info about it on the site, and you a likely to also find what the heads will take without modification. Seem to remember something around .570.

[grc]

While it is always best to measure the actual safe valve lift on the engine in question when contemplating a big change, since Harley has some fairly generous to them tolerances, the stock heads of the CVO 103 were good for at least .590' lift and some have reported measuring over .600".  A common lift for Stage II replacement cams was at the .575" figure.  If you planned on Stage III or IV mods, since the heads would be off anyway then it would definitely be appropriate to set them up with the appropriate valve components to suit the cam you intend to use.

Jerry

Btw, the stock cam has .538" lift, and the specs are shown on the attachment (click on it for full size).  And HD Street Performance is absolutely correct, the heads have huge chambers that kill compression, and no real squish to speak of.  Serious performance upgrades will require head work.

[HD Street Performance]

There are a few cams that say they are specifically for this 103. I would not use them personally. The problem is the motor has very low compression ~8.7:1 (very large open chamber head ~98cc) regardless of what advertising literature states. When you get them up to a high 9 then a lot of cams become viable, even the stocker works better. As it sits now the only strategy would be to put a short cam in it to increase low end grunt but it will fall flat on the top, something it does fairly decent stock.

If it were mine I would budget and plan for head porting, small dome high compression pistons for the open chamber, and a cam change to something like the Tman Torquester 555 or 590 if the compression is a little higher.

The CVO 103 has a lot of potential and works very well IME but it just takes a bit more work and funds to get the power and torque out of them.

[HILLSIDECYCLE.COM]

Just completed a semi-similar 103" with the use of a Wood 8/55mm HPI, 1.800"/Fatcat. 200 psi ccp.
Should tune off REAL nice.
Scott

[Cvostu]

When I did my build on my 04,103.      We took out the stock cams and used s&s 570s.     I think I still have the original cams in the drawer.  If you want them I have. Them.  About 40k miles when I took them out. 

[twinotter]

Even if the heads will run up to .590 lift, you need to carefully check the cam cases to ensure there is adequate clearances for the cam to turn in the case. If I remember correctly, they could run something around .550 max without needing clearance cutting. Back then with HP springs, most rocker boxes had to be clearanced as well. Now with the use of behive type springs on most builds, it likely not an issue.
twinotter

[HILLSIDECYCLE.COM]

And then there can be v/v clearence issues with just dropping a big cam in, just because the springs will accept it.
Not the norm, but we've seen it come in here.
Scott

[timtoolman]

The stock cam in all CVO 103 bikes was the SE253 cam.

You might try to search this cam to find out more info about it on the site, and you a likely to also find what the heads will take without modification. Seem to remember something around .570.

i thought the early cvo bikes had the S.E. 203 cams Which was a split pattern cam or maybe I'm thinking  of earlier model

[hawgzilla]

No CVO bike had a 203 not even the SE 95" motors.

Sure about that???  Pretty sure early cvo 95's had 203's.

[grc]

Sure about that???  Pretty sure early cvo 95's had 203's.

The 2000, 2001, and 2002 CVO 95 engines came with 25937-99B CAMSHAFT KIT SE203, includes front & rear camshaft & required gaskets.

In 2003 they changed to the CVO 103, which came with the SE 253 cams as did all the subsequent CVO 103's.

Jerry

[HD Street Performance]

Thanks Jerry