do they make hollow cams for b series engines, i know the new Evo SE runs hollow camshafts.. would that be a good investment?

 

no one that i know of.
It COULD be a good investment. It must be of some benefit or else manufacturers wouldnt do it.

 

The hollow cams I have seen are just for oem engines.They have powder metal lobes pressed onto a hollow steel core (usually hex shaped).The lobes are formed not ground.They are for economy of production and longevity and really add nothing to performance.

 

EVO SE? The SE pretty much has the same motor as the RS, GSR and the MR. I think you meant EVO IX.

 

Toda VTEC killers are hollow. Benefit?? Who knows...
http://todaracingusa.com/categ...id=69

 

I've read a good deal about these, and it seems to be a pretty even 50/50 split on if it's good or not.

To expand, I've mostly read on OHV motors, that turn almost if not as high as some Hondas. IIRC Nascar motors are all non hollow.

Personally, I think I'd skip them, when I can't understand something 110% I try to err on the side of caution.

 

Something spinning as fast as a cam does, as long as a cam is, being twisted from one end only, and has the pressure from springs on it, I wouldn't want it to be hollow. I like some peace of mind.

 

i know the s2000 has that type of system but its more so for oilling the cam lobes and overall lubrication simplicity but being lighter i guess it has some sort momentum advantage past the vtec engagement rpm...who knows really lighter is better depending on the circumstances...my .02 cents

 

has to do with moment of inertia and the fact that the centers of shafts do very little for the overall strength. so taking it out would lose static weight as well as rotating mass. though the rotating part of the removed section still only contributes a small amount due to the MOI previously discussed.

so theyre good when youre looking for every last little bit.
outter diameter can be increased to offset the center missing as well. these might be designed that way. but then that adds to the MOI in an even worse place, but since youre adding only alittle then it could be weighed out.
still static weight loss though, probably good for a few pounds.

 

If designed properly, hollow shafts can definitely reduce drive train loads at high rpm. As dfox stated the inside off most rotating equipment is along for the ride. The real strength is defined at the outer most fiber of shaft. But that is were the highest stresses are located.