dummy cam question

[dohcfiend]

this is more like a what if and i am always looking for an angle for power and i wanted to run my newest idea past you guys.


can that "dummy" cam be safely lightened to reduce rotating mass? like grinding off the cam lobes or something?

[Anonymous]

I don't think it has any lobes on it. All it has is a gear for the oil pump, and a gear system to run the other cams.

I've had the idea for a while now to drill out the cams(and the intermediate shaft, aka dummy cam), but Ben says it will compromise their strength too much. I have yet to talk to any other professionals about it. I think I remember him saying that most of our cams are already hollow, or at least part of them are.

[dohcfiend]

i have seen one all the lobes are smooth. i was thinking perhaps a professional could grind them down to the diameter of the cam itself but my thoughts were it would have to be balanced or it might break.

when you say intermediate shaft i am thinking of the small shaft that goes to the oilpump. what i am talking about is an actual pushrod style camshaft, you have to remove the entire aluminum assy in the front to get to it and it will be attached to a timing chain.

the one i pulled was pretty heavy, and the 12(i think) lobes don't appear to be in use by anything. if the lobes were grinded off i am (thinking ballpark)about 1/2 lb per lobe, so 6lbs would be pretty good but would it work?

[Fierobsessed]

There are lobes? (or blanks?) My 96 DOHC's don't have any lobes on them, nor any provision for lobes, they just have the 4 journals and the shaft is about 1-1/8" in diameter throughout its length otherwise. It's a necessary evil that shaft...

1/2 lb per lobe? no way. Plus keep in mind that the shaft spins at half crank speed, and at no point does the diameter exceed about 2" or so. If you want to lower rotating mass, concentrate on the crank, flywheel, and harmonic balancer since there diameters are anywhere from 6-12" and they spin at twice cam speed. Unfortunatly this particular engine has a REDICULOUS amount of rotating mass. 4 VERY heavy cams, the dummy shaft, the crank, flywheel harmonic balancer.