Originally Posted by WDCreech
I speak from experience. A gear drive, without a blower belt to dampen harmonics, will eat valve springs in a solid lifter engine. With hydraulic lifters, the springs don't seem to expire so quickly. If you don't want to shell out the big bucks, for belt drive, go with the premium Roll Master chain, made in Australia. They, just, don't seem to stretch!
Amen to that. Crazy harmonics get transferred.
Belts are great, but they don't give you any warning before they break. When they break, the pistons hit the valves and you basically run the risk of turning your engine into recyclable scrap. They absorb crank harmonics beautifully, but unless you're racing with frequent belt inspection/changes, its a little risky on the street.
Gears last a long time, and might make an extra 1/2 hp, but at the risk of severe valvetrain harmonics. Its a hard gear drive. The crankshaft is constantly being hit with the force of a sledgehammer thousands of times per minute. I don't want a direct hard connection to my valvetrain and distributor unless its worth it for that extra couple ponies.
Chains are bulletproof, proven, cheap, and quiet. They also tend to give you about a year of warning before they break. The engine will run like crap, ignition will be all over the board, and the chain will hit the timing cover sounding like a coffee can with a couple bolts swirling around. If you break a timing chain it means you ignored about 10 months of obvious warning signs
I use Cloyes true double roller sets in almost everything I build. I have 126k miles on one right now and its still trucking along