HEMI Technical Info

You are here

Home » Fuel/Clutch/Ignition Management » Clutch Management

Cannon/8.625 Belhousing

How to get 5 disks into a 8 5/8 bellhousing (without buying a 9.4" bellhousing):
A) release bearing clearance --> foot off of pedal, cannon extended .3 - .5"
B) base Arm offset  = .1"
C) pressure plate thickness (donut) = 1.0"
D) clutch pack  3.0" (a all new pack would be close to 4")
E) flywheel  1.15"
F) clearance flywheel to engine plate .06"
Total 5.81"   (new disks = 6.81")  Starting position for release bearing.
Release bearing in picture above is touching (holding away from the pressure plate) this 1st arm,
before cannon starts to move.
12th arm 1.1 + inches (or more) from 1st arm
 Note all 12 arms (or whatever pp came with) aren't required .
----> initial "hit" of engine (add bending of arms,pp, flywheel etc.
----> pack clearance .050" X the arm ratio 6 = .30"
----> Travel of cannon (minimum) to clear arms 1.1"   total travel of cannoc1.8" (to 2.5")
----> wear of clutch pack during the run .08 -- .18" X arm ratio 6 = .60" +
----> clearance after release bearing has passed all arms = ?
Total distance from engine plate  to front of release bearing = at least 8" + bending, clearance+
 Final position of release bearing is "outside" of bellhousing. 
add 1" for all new disks or aprox .6" less for 4 (used) disks.
also check clearance on cross shaft and fork  ***
Add a 1/4" spacer (alowed by NHRA) or thicker to space back bellhousing

enlarge hole in back of bellhousing, note the fork is notched to clear at bottom, and hole incudes transducer "flag"
Another spacer .5" or more Note the bottom will have to be "clearanced" for fork
Clearance in front of cannon.
Optimizing release bearin, push tube clearances.
Also depending on how much travel you need, the shaft (release bearing fork, pedal) is usually moved down in bell housing with a longer and wider fork.
Sheet to keep track of what you wanted / what you got after setup and shimming arms