vettenuts

iTrader: (4)

Just picked up an aftermarket cam and it is solid, not hollow like the stock cam. Are all the aftermarket cams solid or is it by manufacturer?

Just curious

calongo_SS

iTrader: (7)

They are almost all hollow. In fact, I don't even know who is still making a solid cam.

vettenuts

iTrader: (4)

When I did a search, I found some TR cams were solid, some hollow of the same grind. Just curious as to what folks are finding out there.

bowtieman81

iTrader: (35)

Seems fishy to me about being hollow. How can you have a hollow billet steel cam? And just FYI, the factory cams are billet steel as well (according to GM service manual).

vettenuts

iTrader: (4)

They are drilled. I just spoke with Crane, they told me some cams are drilled, others are not. For street driven less aggressive grinds, no difference from a performance standpoint so they don't drill them.

bowtieman81

iTrader: (35)

Interesting. I am surprised that they would go thru the hassle to drill a cam. Is there some advantage to drilling them hollow?

Krab

iTrader: (28)

My Thunder Racing cam is hollow.

GuitsBoy

iTrader: (4)

Gun drilled cams = less weight, specifically rotational weight, albeit a small difference. This makes for a faster reving engine and more hp - although the benefits are far too small to be perceptible at anyone, and likely wont even show up on a dyno.

bowtieman81

iTrader: (35)

Guitsboy, that is the thought that came to my mind, or maybe something to do with harmonics.

It is surprising they would go to the machining expense to drill them hollow. I definitely agree that the difference between drilled cam or not would be indistiguishable.

GuitsBoy

iTrader: (4)

I believe they touch upon the gun drilled camshaft in the "millenium motor" writeup about the ls1, but I cant say for sure, its been a while since ive read it.

777

iTrader: (21)

I'm sure there is a reason for it otherwise people wouldn't go throught the time nor the expense of drilling them.

vettenuts

iTrader: (4)

While I agree, I would think if you were installing a double roller chain any benefit in a drilled cam would be quickly overcome.

Does anyone know if the oil path has anything to do with it? I wouldn't think so, but figured I would throw it out there.

mrr23

iTrader: (3)

a drilled cam is lighter making it less weight. this makes the motor rev ever so slightly quicker. that's all it is. being a solid cam, makes it stronger also. less twist of the cam from front to back. again all about valve event timing for all cylinders. degreeing a cam for very cylinder, you won't see the discrepancy. because the cam is turning so slowly. at 7000 rpms, the shaft is twisting because the timing chain is turning the front of the cam. now, in microseconds, the rear of the cam is turning later. playing catch up per say. torsional stress is another way of looking at it. that's my viewpoint.

vettenuts

iTrader: (4)

I went back into one of my LS1 books and found something on it, the statement made was that it was done for weight saving only. I computed the total weight of the removed material and got 1.86 lbs. I don't see anything that would lead me to believe that there is more to it than that, as the rotational mass moment of inertia between the two is likely in the noise.

I am wondering if it has anything to do with the hardening process? Does anyone know if they machine the cam then harden it or vice versa?

PS: I am happy with the cam, this just has me very curious.

S1LV3R

iTrader: (5)

The guys with the valve trane noise after their cam swap have hollow cams and the guys with the solid cams have less valve trane noise.































J/K