With a direct connection I have heard that vibrations are passed on to the cam from the valvetrain. I dunno, just what I heard
good example of that beautiful sound... http://videos.streetfire.net/search/1000/0/C7BF2E28-32E7-4904-B5F9-F3D0275DC7D8.htm even if it is a cheby...
I have noticed that Chevies sound different with a gear drive. To me a gear drive in a Chevy sounds really metallic and almost like a grinding noise rather than a pretty whine. IMO it has to do with the stamped steel timing cover. The larger aluminum cover on a Ford makes our cars sound so much better with a gear drive. Every Chevy I have ever heard personally has had a steel cover and every one has sounded like a broken chainsaw. I would like to hear a bowtie with an aftermarket aluminum cover to test my theory, but haven't had the chance yet. Side note: My speakers are not working, so I didn't click the link. I don't see how... 50 hp is a HUGE number. I don't think I would trust "they". Think about that for a second... "vibrations are passed to the cam from the valvetrain"... The cam is connected to the valvetrain by the lifters and pushrods, not the cam gear. The only link that is "solid" is the cam gear to the crank gear... and "solid" is not the term I would use either to describe the floating idler gears. The reason that high rpm types used the gear drives so fervently in the past is to lose chain stretch at high rpm. Doesn't mean too much nowadays though as the belt drive has become the new trend in racing. If you use a gear drive on the street, I would think the only benefits you can count on are the longevity and pretty sound. Other than these points, there is no real arguement for or against IMO. Dave
The only downside is the increased harmonics being passed from the CRANK to the CAM. This can cause unstable timing events when taken to the extreme. (Usually in old/worn engines where valve lash may not be correct, springs weak, etc.) Many engines over the years have used a gear drive arrangement instead of timing chains or belts. Saab comes imediately to mind. Most of the OEM versions used a composite plastic/steel gear to dampen these harmonics. No major downside when properly designed and installed. Timing chain stretch and belt failure are two big problems with high milage cars. A chain that jumps a tooth or a broken belt can destroy an engine in 2 revolutions.
Well there is this thing called preventive maintenance. My dad has always told me there is no point in haveing a gear drive in a street car. But whatever floats your boat.
