For those who think custom cams are best... please explain why!
Launching!
Joined: Jul 2004
Posts: 200
Likes: 0
From: Gainesville, Florida
The problem is, the off-the-shelf cams don't appear to be optimized for anything. I never hear someone say their cam works best with 3/4" di headers with a primary length of 32" with cats and a LS6 intake manifold.
And that stuff matters. The length of the header primaries effects the resonance of the pipe, and thus when the low-pressure wave arrives at the valve. You want the valve to be open the right amount to take advantage of this. The same thing happens with a high pressure wave on intake runners.
The backpressure of the whole system clearly effects what the exhaust lobes should be, right? Yet no cam vendor seems to recommend some cams for cutouts and others for cats. I take that back, a GM engineer did publicly state the ASA cam makes no more power than the LS6 cam unless its run through a catless exhaust system. Then I think they said it picks up 20 hp.
Then there are different CRs, port sizes, plenum sizes, TB sizes, valve sizes, gears, rev limiters, and probably tons of other factors I don't know and don't have time to learn a damn thing about.
If vendors advertised cams for specific setups and very specific goals, then I would agree they are just as good as a custom cam. Of course, nothing would suck worse than a custom cam ground by someone who doesn't know what they are doing, heh
And that stuff matters. The length of the header primaries effects the resonance of the pipe, and thus when the low-pressure wave arrives at the valve. You want the valve to be open the right amount to take advantage of this. The same thing happens with a high pressure wave on intake runners.
The backpressure of the whole system clearly effects what the exhaust lobes should be, right? Yet no cam vendor seems to recommend some cams for cutouts and others for cats. I take that back, a GM engineer did publicly state the ASA cam makes no more power than the LS6 cam unless its run through a catless exhaust system. Then I think they said it picks up 20 hp.
Then there are different CRs, port sizes, plenum sizes, TB sizes, valve sizes, gears, rev limiters, and probably tons of other factors I don't know and don't have time to learn a damn thing about.
If vendors advertised cams for specific setups and very specific goals, then I would agree they are just as good as a custom cam. Of course, nothing would suck worse than a custom cam ground by someone who doesn't know what they are doing, heh
Why custom's are best in my world.
I deal with engine builders only. These guys have to produce for their customers, especially their top customers. That extra 30#/ft of torque in that 360CID late model could mean the difference in 1st and $10K to win or 2nd and $2500. Now do these guys use shelf stuff, sure. . for the most part they do, but when they have a customer willing to spend the extra doe, then I get a call. Whether it is stock heads or $12K set of 12X's, some will go custom, most will go shelf, but if you are looking for an edge, custom is the way to go.
Let's relate this to food, for most a good steak comes from the Outback steakhouse and I agree, but if I want a really good steak, I pay the extra and go to Morton's.
Chris
I deal with engine builders only. These guys have to produce for their customers, especially their top customers. That extra 30#/ft of torque in that 360CID late model could mean the difference in 1st and $10K to win or 2nd and $2500. Now do these guys use shelf stuff, sure. . for the most part they do, but when they have a customer willing to spend the extra doe, then I get a call. Whether it is stock heads or $12K set of 12X's, some will go custom, most will go shelf, but if you are looking for an edge, custom is the way to go.
Let's relate this to food, for most a good steak comes from the Outback steakhouse and I agree, but if I want a really good steak, I pay the extra and go to Morton's.
Chris
