JESEL BELT DRIVE
Instead of using a conventional oiled timing chain setup, we opted for Jesel’s way-cool belt drive system. This offers adjustability, precise cam timing and the belt soaks up any operational harmonics.
The first step is to install a stock-type big block Chevy timing cover gasket to the block face. I smeared a thin coat of RTV on both sides of a Victor-Reinz gasket for insurance (habit). The Jesel aluminum cover housing is installed next. This cover is secured with six 1/4″x20 socket head cap screws, which I tightened to 50 inch-lbs.
Next, a brass thrust washer is oiled (on both sides) and slipped over the cam nose. This is followed by the cam nose adapter. For sealing purposes, a light coat of RTV was applied to the rear face of the adapter where it meets the cam nose face. Jesel supplies a handy spanner wrench to hold the cam steady during bolt tightening. Three 5/16″ x 18 torx-drive bolts are supplied, as well as a handy T-45 torx bit.
Jesel recommends applying a light coat of RTV to the three bolt threads. These torx bolts were tightened to 30 ft-lbs (Jesel’s range is 28-30 ft.-lbs).
Next, another brass thrust washer is installed to the outside perimeter face of the adapter (oiled on both sides).
The next step is to install the shim pack supplied in the kit. I installed all three shims (these locate over the six 1/4″x20 studs on the face of the cover), followed by the seal-fitted shim cover flange. In order to avoid damage to the rubber seal, I first removed the small key from the cam nose adapter.
With the shims and shim flange installed, it was time to check camshaft endplay.
According to Jesel’s instructions, camshaft endplay should be 0.010″-0.015″. When I checked our cam endplay (using all three shims supplied in the kit), shims must be added or removed in order to achieve a cam endplay of 0.010 to 0.012″.
When I set up my dial indicator, I found endplay to be 0.017″. I called Jesel to ask their advice, and one of their tech guys assured me that 0.017″ would be acceptable.
With cam endplay verified, I removed the thrust flange and the three shims. I lightly coated all shims and the rear face of the flange with RTV and reassembled, using the supplied 1/4″x20 nyloc jam nuts, tightening these to 50 in-lbs.
With the shim pack and flange final-installed, I re-installed the small key to the cam nose adapter.
Next, the crank gear drive is installed (I installed a pair of keys measuring 0.185″ thick x 0.735″ long and 0.300″ high into the snout’s key slots). This is an interference fit, requiring a driver, which is supplied in the kit (big honkin’ aluminum driver that slips over the crank snout). The crank snout features a slight step-up in diameter. When the gear is slipped onto the crank and hand-stops, it will then be driven on another 0.384″ (in our case) until it seats.
At this time, rotate the crank to place the crank gear’s timing dot at 12 o’clock.
The cam adjuster plate drops over the four studs on the black cam gear and must be assembled with the cam timing mark at the top, aligning with the center (zero) timing mark on the adjuster. Install the cam gear and adjuster plate onto the keyed cam nose adapter. Next, install the cam locking flange using the left-hand thread bolt provided. Snug this just enough to keep the cam gear keyed in place.
With the four adjuster plate-to-cam gear nuts installed with about one and a half threads, tilt the top of the cam gear forward to “slip” the timing belt into place. This will take a few minutes, since you need to keep the timing dot on the bottom of the cam gear aligned with the top dot on the crank gear. The belt’s a tight fit, so patience is definitely required. Once the belt is in place, you can snug the four 12-point nuts to secure the adjuster plate to the cam gear.
Once the timing belt is in place, with both dots aligned (cam gear dot at 6 o’clock and crank gear dot at 12 o’clock) and with the cam adjuster marks set at zero, tighten the cam gear’s center left-hand-thread bolt to 70 ft-lbs (you’ll need a 12-point 5/8″ socket for this bolt). Now you’re ready to degree the cam.
Although I admit that this was my first attempt at installing a Jesel belt drive, and it may have seemed daunting at first glance, it actually wasn’t that big of a deal. Since the oil is sealed by the rear cover, the belt drive is exposed, making cam adjustment easy. And, the exposed belt drive looks totally cool.
INSTALLING THE RODS/PISTONS
I first installed the oil ring support rail at the bottom of the oil ring groove. The support rail featured a small male dimple which must be located at the center area of the pin bore, facing down.
I then installed the Perfect Circle ring package, including oil rings, second ring and top compression ring. With the cylinder and piston ring area well-oiled and the Clevite coated rod bearings in place (rod bearings lubed with Max Tuff lube), the piston/rod was slipped into the bore, rings compressed and the assembly was slid home onto the crank rod journal. Aside from use of the support rail, nothing funky. By the way, a “traditional” ring expander tool isn’t sufficient to spread the rings far enough to drop over these big pistons. Ammco makes a better tool that will handle up to a 5″ bore, their P/N 8330.
The Lunati 7/16″ rod bolt threads and nut faces were coated with ARP moly lube. The rod bolt nuts were initially tightened to a value of 40 ft-lbs, followed by careful stretch-tightening to achieve 0.005″-0.0055″ bolt stretch (for tightening by torque value alone, the bolts should be tightened to 73 ft-lbs, with moly, but we prefer the stretch method). I started with number one cylinder (all we needed for degreeing the cam), followed by the remaining seven pistons/rods after the cam was timed.
CHECKING CAMSHAFT TIMING
Instead of degreeing our cam using a degree wheel, Rick Kotsull and Joe Malecki from CamLogic Technologies were kind enough to visit our tech shop, to help us degree the cam using their CamLogic digital degree system. I saw a demo on this deal at the recent PRI show, and it’s really very cool. It uses no degree wheel.
Instead, an encoder unit keys onto the crank snout and the billet encoder body then anchors to the block face using an existing timing cover bolt hole. The encoder, which monitors crankshaft angle, is wired to a digital display unit. A cam lobe dial indicator is mounted into a lifter bore (in our case, we used No. 1 cylinder’s intake location), and a dial indicator is positioned over the cylinder, contacting the piston dome center.
Rotate the crank (in normal direction of rotation) any distance before TDC (typically 0.050 – 0.100″). Stop and press the BTDC button on the display unit. Next, continue rotating the crank past TDC to the same value used previously (we used 0.050″). Stop and press the ATDC button on the display unit. The unit’s microprocessor electronically positions itself at true TDC.
Next, rotate the engine (in normal direction of rotation) to any position before maximum lift (we used 0.050″), stop and press the POS 1 button on the display unit. Continue rotating the engine past maximum lift to the same value that was used for POS 1. Stop and press the POS 2 button. The display unit constantly shows crankshaft angle in addition to the calculated lift, so not only can you verify when max lift takes place, but you can also monitor the entire lobe travel, noting the ramp-up and ramp-off angles.
Checking our cam on the 632 took a grand total of maybe 10 minutes. The system isn’t all that expensive either (much less than I had thought, to the tune of around $800 or so). The base kit includes the encoder and digital display unit. Crank adapters, dial indicators and indicator mounting hardware are available as options. A variety of aluminum crank adapters are available for Chevy, Ford, Mopar, Pontiac, etc. Dial gauges are available as options or you can use the ones you already have.
The CamLogic base kit includes the encoder and digital display unit. Dial indicators, indicator mounting hardware and crank adapters are available as options.
The digital display unit is powered via a wall-plug-in cord. Operation is really very simple and straightforward.
The encoder plugs into the digital display unit.
Crankshaft adapters are available for all popular smallblock and bigblock GM, Ford and Chrysler applications.
Thanks to the following for their involvement in this project…
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ATI PERFORMANCE PRODUCTS
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CLEVITE ENGINE PARTS
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CRANE CAMS, INC.
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DIAMOND RACING PRODUCTS
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GOODSON TOOLS & SUPPLIES
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HOLLEY PERFORMANCE PRODUCTS
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JESEL VALVETRAIN INC.
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(see Holley Performance Products)
MEZIERE ENTERPRISES INC.
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MOROSO PERFORMANCE PRODUCTS
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PRO-FILER PERFORMANCE PRODUCTS
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ROYAL PURPLE, LTD.
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SUNNEN PRODUCTS CO.
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