Jet Boat Performance
Jet Boat Drive Line Information
This is the most common modern replacement H-bar drive line for jet boats. The overall length measures 7 1/2" (± depending on manufacturer, Panther Drivelines measure slightly shorter), the round register on the flange measures 2 3/8" and the rectangular bolt pattern measures 2" x 2 3/8" typically using 3/8-24NF bolts (grade 8). This type of Driveline is designed to be used with a PTO flange (Power Take Off, pictured below) in order to adapt this universal drive line to many types of engine crankshaft patterns (also flywheel or flex plate). This type of driveline also comes in a 1350 Version (not pictured) utilizing beefier u-joints, h-bar and overall construction. The 1350 measures approx. 8 1/4" long, has a rectangular bolt pattern measuring 2 3/8" x 2 7/8" and typically uses 7/16-20NF bolts.
Available in 1310 and 1350 versions for most common V8 engine as well as many other oddball engine combinations. This flange generally measures 3/4" - 1" thick.
Rockwell H-Bar Drive Line
This was an H-bar driveline produced for a specific engine in mind and bolts directly over the flywheel/flex plate to the crankshaft (mounting flange pattern will vary depending on specific application. Most commonly produced in Oldsmobile (flywheel), Chevrolet (flex plate) and Ford (385 series 429-460 Flex plate). These drive lines were used most commonly in Berkeley Pack-a-Jet combinations (3 point engine mounts with short bellhousing) and in Jacuzzi jet set-ups utilizing a mid point saddle mount and a pump mounted rear engine bracket.
This style drive line incorporates a very compact design measuring only 6 3/4". It also uses larger 1350 size U-joints. However this particular drive line has not been produced as a new replacement driveline in many years.
Unfortunately in cases where this drive line is either missing or beyond repair, in the absence of an equivalent replacement, it is routine to replace with the 1310 Spice driveline and a PTO. This however requires the engine to be relocated forward approximately 2" and generally requires modification to existing engine mounting hardware or replacement.
Long H-Bar Drive Line
These drive lines are much like the above mentioned Rockwell in that they are engine specific, except these measure in at approximately 8 3/4". Most commonly came on Harman Marine engine packages (using long pump mounted bellhousing or four point engine mounts), also commonly used in Panther jet combinations (with a short pump mount bellhousing). This used 1310 size u-joints. This assembly can generally be replaced by the 1310 Spicer Drive Line and a PTO without modification.
The above information is not the extent of all the drive lines used in Jet Boat applications, just the most common.