When overhead cam cylinder heads and engine blocks are machined to flatten their head gasket surfaces
the cams are moved closer to the crankshaft and consequently the cam timing relative to the
crankshaft is changed. In addition, if the engine is a V-type (like the Z32's VG30DE is), the cam timing will
change differently for each side of the engine.
This cam timing change usually necessitates degreeing the cams with an adjustable pulley to get the
critical cam opening/closing events back in sync with the crankshaft. If the cams are degreed using the
adjustable pulleys that have been available until now, the numbers on their scales would have no relevance
whatsoever to their original zero marks when finished. To add to the confusion, a V-engine's different
side to side change typically leaves the final degreed setting of each pulley on a different number of
their scales... that is "if" they ever came with a zero mark reference.
Enter the BDE Bullseye Adjustable Exhaust Pulley - After the cams are degreed to the crankshaft, the unique
BDE outer ring adds a third timing element which can be rotated to align with the scale's zero mark so
future adjustments can easily be made without the hassle of remembering where the original degreed setting
was. Now the vernier scale actually means something after the cam degreeing process. For fresh builds,
the pulleys can easily be set to true zero by visually centering the bullseye and then setting the scale's
zero to the ring's timing mark.
Other features of the Bullseye Exhaust Pulleys are:
- Works with '90-'93 Mitsubishi CAS only, '94+ Hitachi CAS requires slight modification for clearance.
Click here to identify your CAS and see the modification required to use the Hitachi CAS.
- Lighter weight than the original pulleys - stock weighs 2.04 lbs. while the Bullseye weighs in at 1.29 lbs.
- ARP stainless steel adjustment bolts with over-sized heads utilize washers to help prevent movement
of the assembly while tightening the bolts and to prevent damage to the pulley.
- Adjuster bolt holes are helicoiled.
- Forget about cores, BDE adjustable exhaust pulleys are 100% machined from billet 6061 T6 aluminum and
don't reuse any stock parts.
- The cog is hard anodized for serious protection from belt wear while the center hub and ring are both
anodized black and feature easy to read white timing marks.