Tavia Performance Specialty Tools and Accessories
Tavia 08070 thru 08072 Degree Wheel Instructions
There are three alternative ways to find Top Dead Center (TDC): (1) positive stop, (2) dial indicator, or (3) positive stop through the spark plug hole with heads installed. Bolt a pointer to cylinder block. If cylinder heads are removed, use either a positive stop or dial indicator.
Find approximate highest point of piston travel,and tighten degree wheel with TDC (0) mark in line with pointer. Then, securely mount positive stop or dial indicator to top of block. Rotate engine clockwise until piston touches. Stop. Check readings on degree wheel.
Then rotate engine counter-clockwise until piston touches. Stop again. Check reading on degree wheel. TDC is halfway between the stop readings. If preferred, use specific dial indicator reading on a dial indicator to obtain the same result as using a positive stop.
The method used with cylinder heads installed is accomplished by using Tavia's #08065 or #08068, adjustable Top Dead Center Stop. Screw it into the spark plug hole so that it will extend ½". Then follow the procedure used with positive stop method.
CHECKING CAMSHAFT TIMINGInstall camshaft, timing gears, timing chain, and align timing marks in usual manner using factory timing marks. Install pointer and degree wheel. Find TDC using one of the three methods described above. Insert intake and exhaust lifters for cylinder being checked. Mount dial indicator (or an indicator with 1" of travel recommended) securely to the cylinder block, keeping indicator stem aligned with travel of lifter.
Starting with intake lifter, rotate engine (using flywheel or flywheel end of crankshaft, so as not to disturb degree wheel), until lifter is on heel of cam lobe or all the way down. Set dial indicator on top of lifter, compressing stem of dial indicator at least .020 of travel. Adjust dial so needle points to "0".
Rotate engine in normal running direction until dial indicator needle reaches checking clearance or tappet clearance recommended by camshaft manufacturer (usually listed on timing card supplied with camshaft). Note reading on degree wheel. This should correspond with the manufacturer's intake opens specifications.
Continue rotating engine in same direction until dial indicator reaches checking clearance (lifter in closing position). Note reading on degree wheel again. This should correspond with manufacturer's intake closes specifications. Exhaust lifter timing should be checked following the same procedures.
If readings do not correspond with manufacturer's specifications, repeat complete procedure. If readings repeat, correct timing by the use of off-set cam bushing or off-set key, depending on make of engine.
Keep in mind, the degree wheel is only as accurate as the person using it, and proper camshaft installation requires proper degree wheel use.
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