FooFighters92

iTrader: (2)

From experience what do you guys think is better and why? Are there any performance differences?

And if you like gears would you go for the noisy or 'quiet' gears, thanks.

vetteoz

iTrader: (13)

Gears are not needed for street applications; are used in race engines to prevent timing changes at hi revs

88gunmetalgta

iTrader: (1)

Even then, lots of race engines run jesel belt drives.


I've heard (NOTE: this IS hearsay) that the gear drives can transmit vibration and "noise" into the valvetrain, and that the little bit play afforded by a chain or belt can dampen that and save a little wear and tear on the valvetrain.

AlkyIROC

Depends on what kind of gear system you want to run. I'll never recommend any dual idler systems to anyone, noisy or quiet. They're just not worth it.

For a basic street strip type car, a good chain system is worth it. Get one with billet gears and expect to replace it when it starts to stretch since it won't last forever. The longest lasting chain system is an OEM design.

If your budget allows, a timing belt system is very good but expect to pay around $1000. They're usually an open system so for street use, the belt could get damaged. When I was shopping around for a new system, I considered a few of the higher end brands such as Comp Cams, Jesel, CV Products and Danny Bee. Stay away from the inexpensive ProComp junk. It's not even good enough for a street car even though it looks just like the Comp Cams belt drive system. There's only a couple of wet belt systems but they're more expensive than the dry belts.

I eventually went with a Milodon single fixed idler system. It takes a bit to get it set up but it'll be the last timing system I need to buy for my engine. Quiet as a chain or belt, stronger than a belt and will never wear out, stretch, break etc.

keithnh

Considering a belt system for the street on my 350 to 302 conversion as a way to uncouple harmonics from valvetrain to add silkiness to high rpm excursions, have increased adjustability and possibly longer life than chain. Fastburn heads,solid roller cam, narrow self-aligning roller-rocks and beehive conversion. Was thinking belt might be easier on that set-up. Wondering about ...

Wet or dry setup?

Why some setups appear to have an idler others dont?

How cam timing is more adjustable since belts all have teeth?

Are there setups that are enclosed and open for sbc?

AlkyIROC

Wet and dry belt systems are expensive. There should be both available for SBC.

Dry is open to road debris which may damage the belt.

The systems with idlers are adjusted for belt stretch, line honing etc by buying different size idlers. Non idler systems are no different than chains but if the block has been line honed, the belt or chain will be loose as line honing moves the crank slightly closer to the camshaft. You can buy shorter chain sets to compensate. Not sure about belts.

Cam timing is done with a 2 piece cam gear. A hub is bolted to the camshaft. The outer gear has multiple index holes to bolt to the hub. Depending which index holes are lined up can advance or retard the camshaft. Some systems also can use a 2 piece cam gear but use slotted holes to adjust the cam timing.

For street use, stick with a high quality timing chain. Billet gears, true roller etc.

keithnh

Guess I feel that if Jesel is making high end belt setups for huge HP racing there must be something to the uncoupling of crankshaft vibration/harmonics from the valve train. I am trying to make a reliable road engine that will see higher rpm occasionaly but on a routine basis. Was hesitant and missed a Manley setup a month or so I should've grabbed. Comparable to Comps wet belt system. Something just felt worrisome about having a belt in the oil galley controlling timing. I do like to use Lucas and visions of the belt coming off scared me away. This motor is a bit of an experiment however so its not off the board yet.

Are there closed dry systems, thought I saw the Butler pontiac sytem just had plates sealing off the oil galley, this seemed most appealing but expensive. Comp has a 5100 wet system and 6100 dry will check them out some more.

Be interesting to see side by side comparison of strictly mechanical timing variance on acceleration and deceleration belt vs chain initial 10K 50K 100K.

Same amount of teeth on chain and belt sprockets?