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Inboard Endurance

Do You Have What It Takes?

In the early days of powerboat racing, Inboard Endurance races were ultimate test; the 100-500 mile races challenged both man and machine to the limits of their abilities, and then challenged them to go further.  The rich history of Inboard Endurance racing and the marathon races of the 1960's and 70's have helped to shape this category to what it is today. While today's inboard endurance races typically run from 15min to 1hr, the attitude hasn't changed. Inboard endurance racers push themselves and their boats as hard as they can for as long as they can, and hope that it holds together. 

Classes

Currently there are three competing classes of IE in the APBA — Grand National Class, Competition Jet, and GPS 95. Today’s races generally run about 15 minutes each, with an occasional 30-minute or 1-hour event. The all-out “push it as hard as you can, hope it holds together” attitude has always been the trademark of a great GN race. From the drop of the green flag launching the crowd-pleasing Le Mans start, through the checkered flag signaling victory, you are guaranteed to enjoy the show.


Do you think you have what it takes to build and run hulls and engines to withstand the grueling test of an Inboard endurance race?


Contact Information

Chairman:  Ted Kolby

Commissioners:  Darrin Sousamian

                                   Heath Hiebert

                                   Terry Valore

Competition Jet
GPS-95
Grand National

Competition Jet

The Comp Jet (CJ) class has quickly become a very popular Inboard Endurance choice.  Virtually any hull up to 24 feet long with two stringers may run in the class. 

Powered by a U.S. built automotive or light truck engine and a single jet drive used for marine applications only. The engine is to be located forward of the jet drive, and the driver must be seated forward of the engine. This is a great way to get into the thrilling world of Inboard Endurance racing.

Endurance  Boat Racing
Requirements
Minimum Age: 
18 years old
Engine: 
U.S. built automotive or light truck engine, Chevrolet big block, maximum 515 cu. in. Cast iron cylinder block; aluminum heads are optional. Naturally aspirated, any form of carburetion or fuel injection is allowed
Speed: 
70 - 90 MPH
Hull: 
Any up to 24' long, with 2 stringers
Propulsion: 
Naturally aspirated, any form of carburetion or fuel injection is allowed
Engine Block: 
Chevrolet big block, maximum 515 cubic inches
Cylinder Heads: 
Cast iron cylinder block, maximum of two valves per cylinder, aluminum heads are optional.
Cam/Lifters: 
No overhead cams allowed
Induction: 
All intake manifold bases must be cast for a minimum distance of three 3" from the intake cylinder head interface/spacer
Ignition: 
No restrictions on valve train or oiling systems.
Statistics
Competition Record: 
79.330 MPH
Straightaway Record: 
113.323 MPH
Previous Season National Champion: 
No National Champion

GPS-95

Requirements
Minimum Age: 
16 years old
Minimum Length: 
16'
Engine: 
Block-Single American automotive block with a maximum cubic inch displacement of 500.
Speed: 
95.9 MPH maximum speed
Statistics
Previous Season National Champion: 
No National Champion

Grand National

The Grand National (GN) endurance race was once 100 miles or more. (The boats must carry 50 gallons of fuel.) Today a GN race may be 5 miles, one hour, two 10-lap heats, or a combination of the above. Grand Nationals draw crowds to the riverbanks to hear the roar of engines and feel the suspense: Who can hold out to the finish line? The class uses any V-bottom or monohull up to 25 feet long. No tunnel over 1 inch deep, hydroplane or step-type hulls are allowed. The GN race boat is propeller-driven, powered by a U.S.-made automotive or light truck Chevrolet or Chrysler engine mounted rear of amidships.

Big block boat engines
Requirements
Minimum Age: 
18 years old
Engine: 
Chevrolet Big Block, Chrysler B/RB or Chrysler Hemi-based engines. Supercharged = 475 c.i max, Naturally Aspirated = 525 c.i max.
Speed: 
100+ MPH
Minimum Weight: 
No minimum; average is 2500 lbs.
Fuel: 
Gasoline only with no additives
Hull: 
Monohull - V-Flatbottom; No tunnel over 1 inch deep, hydroplane or step-type hulls allowed.
Propulsion: 
American-made automotive engine mounted to rear of amidships and driving forward through a v-drive to a stationary strut mounted propeller. Gearboxes are permitted.
Engine Block: 
Cast iron engine blocks only
Cylinder Heads: 
OEM or aftermarket. Iron or aluminum with common wall intake ports
Cam/Lifters: 
In block, any style. Overhead cams are not allowed in this class.
Blower: 
Must be Roots type blower
Max Overdrive: 
8-71: 1.03:1, 10-71:0.95:1, 14-71:0.83:1
Induction: 
Any except for turbochargers
Ignition: 
Any
Est. Horsepower: 
875HP - 925HP
Statistics
Straightaway Record: 
116.263 MPH
Previous Season National Champion: 
Body Snatcher GN-24 Ted Kolby