V8 Cam profiles
LancasterWannaBe
07-31-2003, 04:54 PM
Is there anything out there like VTEC, but designed for big block v8s
454Casull
08-02-2003, 12:31 AM
A lot of European V8 engines have variable valve actuation.
V-8Fan
08-03-2003, 10:53 AM
There is nothing as elaborate as V-TEC available for common V-8s that would be considered affordable...and maybe nothing NOT affordable. Yet. But I'll bet the aftermarket head manufacturers are working on it.
But, there is one thing that is relatively cheap and is effective, and that is the Rhoads-style lifter. You don't get the extreme flexibility that the V-TEC system is capable of, but it still works.
They work by "pumping up" at higher RPMs. Errr, well, maybe it would be better to say they "pump DOWN" at low RPMs. You get to select a wilder cam profile, but you retain driveability because they effectively reduce duration at low revs. Then as your RPMs increase, they begin to give full cam action---full lift and full duration. You get the best of both worlds. And that's basically the same thing the V-TEC system does, only SIMPLER. Simple is good!
I've seen the results of Rhoads lifters on a basically stock Chevy 350, and I was impressed. The cool thing is that they are not much more expensive than stock hydraulic lifters. The unfortunate thing is that it would probably be difficult to get them to work right on a computer-controlled engine. Or maybe it would be more correct to say that a wild cam is something the computer just couldn't understand.
But, there is one thing that is relatively cheap and is effective, and that is the Rhoads-style lifter. You don't get the extreme flexibility that the V-TEC system is capable of, but it still works.
They work by "pumping up" at higher RPMs. Errr, well, maybe it would be better to say they "pump DOWN" at low RPMs. You get to select a wilder cam profile, but you retain driveability because they effectively reduce duration at low revs. Then as your RPMs increase, they begin to give full cam action---full lift and full duration. You get the best of both worlds. And that's basically the same thing the V-TEC system does, only SIMPLER. Simple is good!
I've seen the results of Rhoads lifters on a basically stock Chevy 350, and I was impressed. The cool thing is that they are not much more expensive than stock hydraulic lifters. The unfortunate thing is that it would probably be difficult to get them to work right on a computer-controlled engine. Or maybe it would be more correct to say that a wild cam is something the computer just couldn't understand.
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