A quality beltdrive timing...
A quality beltdrive timing system not only uses less horsepower than a conventional timing chain setup, but it can also dampen power-robbing valvetrain harmonics.
Beltdriven timing systems are nothing new in racing. Their usefulness was first proven in NASCAR's Sprint Cup Series, and since then the technology has trickled down to Dirt Late Model racing, the ARCA series, and other upper-level racing classes.
Although they are more expensive than a traditional timing-chain system, a beltdrive has several advantages that can show up on the race track. First, the belt helps absorb power-robbing harmonics in the engine. This helps smooth out the impulses transmitted to the camshaft and valvetrain and can improve overall control of the valvetrain. A belt also doesn't stretch over time, and it won't develop "slack" in the system like a chaindriven system can. Also, a belt system with intelligently designed cogs that mesh well with the pulleys works much more efficiently than a chain and will sap less horsepower from the engine-meaning more power to the rear wheels. And finally, if you feel you will need to make camshaft timing adjustments, a belt system is definitely the way to go because it does not require oil, and therefore, can be made to be easily accessible to so you can make your changes on an adjustable cam pulley.
Normally, one of the biggest complaints about using a beltdrive timing system is the hassle of getting it properly installed. Traditional beltdrive systems use packs of shims to set the camshaft endplay. Not only was finding the right combination of shims time consuming, but they often had to be modified with oiling holes to keep them from burning up or galling against the drive.
CV's new Xceldyne beltdrive timing system does away with all that by replacing the shim packs with an innovative new thrust bearing. In fact, this new "Low Drag Cam Thrust Bearing Assembly" is so innovative it was awarded patent number 7,331,319 this past February. CV says its new thrust-bearing design utilizes "precision-ground 44c stainless ball bearings in a perfectly balanced assembly" which eliminates the cam hub, seal plate, cam shims, and Torrington bearings found in more standard beltdrive systems. The bearing is lubricated by engine oil from inside the crankcase, eliminating the need for special oiling arrangements. The oil seal is also built into the bearing to further simplify the assembly.
To get a better idea of how CV's new beltdrive timing system works, we stopped by the shops of KT Engine Development in Concord, North Carolina, while owner Ken Troutman installed a kit on an engine to be raced in the ARCA series. CV says kits should also be available for Ford small blocks by the time you read this.
On a Chevrolet there should...
On a Chevrolet there should be no machining required for the back cover to fit properly. Still, it is a good idea to check and make sure there is some clearance between the front of the engine and the back of the plate to allow oil drainback. This can be done with a couple pieces of clay. Place the clay at the highest points on the block and then press the cover into place. There was plenty of clearance on this block which has already had all the internals polished.
The cam cover plate seals...
The cam cover plate seals against the block with an O-ring cord that fits into a machined groove in the plate.
Notice how the groove for...
Notice how the groove for the O-ring cord is cut in a dovetail. This helps capture the cord so it cannot slide out of position. Once the O-ring cord is pressed into position, wipe away the excess and apply a small dab of silicone in the area between the cord and the beginning of the oil pan rail.
The next step is to install...
The next step is to install the crankshaft seal. The cover has a lip machined into it so that the seal must be installed from the front. The lip keeps the seal from being pressed too far into the cover and also provides an additional sealing surface.
The crank seal is constructed...
The crank seal is constructed from aluminum and will warp if you try the old-school method of tapping around the outside edge with a hammer. Instead, you must press evenly all the way around the seal at once. CV Products sells a tool for pressing in the seal that makes the task as simple as possible.
Gently put the rear cover...
Gently put the rear cover into place being careful not to twist or rip the crank seal. You may need to run your finger along the lip of the seal (it is a double lip suitable for either wet-sump or dry-sump applications) to relax it so that it will slide over the nose of the crank more easily.
Make sure there is some clearance...
Make sure there is some clearance between the back cover and the front main cap. You just need enough to allow oil to drain into the pan. If there is none, create a channel for the oil to drain into the pan by cutting a small groove into the cap-not the cover.
CV provides quality 1/4-20...
CV provides quality 1/4-20 ARP bolts for attaching the cover to the block. Use blue Loctite and torque them to 10 lbs./ft. Notice that Troutman has left the bolts out where the timing pointer will eventually be installed.
This is the cam thrust bearing...
This is the cam thrust bearing assembly that makes this camshaft timing drive so different from all the rest. Before installation, make sure to completely clean the bearing to remove any remaining antirust agent that was applied prior to packaging. Then you can lightly lubricate the bearing with motor oil.
Make sure to test fit the...
Make sure to test fit the bearing assembly prior to final installation. To make later assembly steps easier, make sure the dowel pin on the camshaft is in the three o'clock position.
The kit includes a seal that...
The kit includes a seal that must be pressed on to the front of the bearing assembly, and like the crank seal, trying to tap it into place with a hammer will only lead to frustration and an oil leak. Again, if you cannot find a method to safely press the seal into place, CV provides a custom tool (part number CVT-CD1) that makes the process a snap.
To prevent leaks, apply a...
To prevent leaks, apply a thin bead of silicone around the inner side of the flange on the bearing assembly.
Six locknuts hold the bearing...
Six locknuts hold the bearing assembly to the back cover. They should be torque to 10 lb-ft with no Loctite.
Apply red Loctite and install...
Apply red Loctite and install (but only finger-tighten) the three 5/16-18 bolts that connect the camshaft to the camshaft thrust bearing assembly and visually check to make sure that the camshaft's lifters are centered underneath the lifter bores. Although it shouldn't be necessary, CV products does sell shim packs to correct for both improper camshaft location and endplay in the event you get an odd cam or something else happens.
Troutman uses a screwdriver...
Troutman uses a screwdriver to gently check endplay.
If everything is to your liking,...
If everything is to your liking, you can torque the three cam bolts to 28 lbs./ft. It can be difficult to hold the cam steady while torquing the bolts this much. Resist the temptation to jam a screwdriver through one of the lifter bores to lock the cam in place. Instead, CV sells a spanner (CVT-CD3) that you can see here that you can use to lock the cam in place.
Install the included Woodruff...
Install the included Woodruff key into the hub of the cam thrust bearing assembly. If the dowel on the cam is at three o'clock, the slot in the hub will be at twelve o'clock, making the dowel easy to hold in position while you tap it in place with a brass punch.
This is the cam pulley. It...
This is the cam pulley. It allows minute adjustments to easily and quickly advance or retard the camshaft as much as four degrees.
Install the crankshaft pulley....
Install the crankshaft pulley. It should be a tight fit. Here, Troutman is using the same tool he used to install the crank seal to protect the pulley as he gently taps in into place with a dead blow hammer.
With the cam pulley still...
With the cam pulley still not bolted into place, the belt and pulley can be positioned.
The crank and cam pulleys...
The crank and cam pulleys are aligned by setting the timing marks so that the dot on the crank pulley bisects the two dots on the cam pulley.
The bolt holding the cam pulley...
The bolt holding the cam pulley in place is a left-hand thread. Make sure it is lubricated with ARP Moly lube and torque to 70 lbs./ft. You will need a separate wrench on the crank to hold the assembly still while torquing the retaining bolt. Now you are ready to degree in your camshaft, install the cover and finish the engine assembly.