Cam Lobes

Was lookin at the stock cams I took out of the 2008 Electragide.

Can you believe that the cam lobes are pressed on the cam.

Yep. Are they welded too, or just pressed?

I've had Sportster cam lobes made @ Zippers & one very interesting thing I learned from talking with the owner & chief engineer is why they make cams the way they do - seems H-D spent like 16 years developing the machining processes for Sportster cams (there are 4) & nobody in the world does it better. Aftermarket Sportster cams are noisy & the reason is the gears aren't cut as precisely.

So what they do is take your set of cams, grind the stock lobes off on a CNC machine & with another CNC machine make new lobes (whatever you want for the application) & press those on. Then weld so the lobes don't move, but they won't weld if you want to play with the valve timing yourself. But the key point is they don't touch the gears, which were matched from H-D to begin with, so when you put your old/new cams back in, you know the gears will mesh perfectly. Their way works like a champ too.

Yep, standard practice if you've got CAD-CAM & CNC equipment to use whenever you want

Unfortunately I don't have a couple million $$$ to spend on it :gah:

And I don't know of anyone other than Zippers ("Redshift" cams) who modifes cams the way I described - I know Andrews doesn't.

I have some pictures of a cam with broken lobes, I will see if I can find them and post them, I believe it is on my home computer so it may be a few days till I get to it, Todd

I'd be very interested to see those pictures. Always like to study broken parts to figure out why they broke - sometimes you already know due to the situation, sometimes you have to examine the parts to figure out why.

Next to my ECTA Champion trophy I have a piston with holes punched in the top, a bent pushrod & a valve with no stem to show off - this is what happens when an exhaust valve-stem breaks. Why did it break? Now I know. And it won't happen again

pressed on cam lobes

As an ex machine repairman for gm, we used to press a lot of bearing and bushings on shafts all the time. Having heard of this in 07 don't know if done before, still it doesn't bother me any...
If done right and the right tolerance is applied to the spline fit as I would bet it is, the lobe should last at long and not have any more failures than a solid cam make from 1 peace.
Haven t heard of any problems yet with this... remember the lobe lifts the lifter, pushrod and the valve in one direction only, not back and forth action on the cam...

found it, I got this off of another forum a while ago I dont know the story behind this but I thought it was interesting so I saved it, Todd

Cam lobe

Duke: do you have any more info on what year or anymore info on what happened...

I dont remember the details, but it was a 07 or newer, I can tell that by the cam, sorry for not paying more attention, I guess I wasnt to concerned because I usually replace the cams in my bike right away anyway, I dont think it is to widespread of a problem or we would have heard alot more on it by now, If I run across some more info on this issue I will be sure to post, Todd