If you wheel your 4x4 in water and you want to learn the finer points of waterproofng, take a gander at the swamp buggies that race at the Florida Sports Park in Naples, Florida. The builders of these rigs are deep- water geniuses who have figured out how to keep their rigs running, even when using them as submarines.
Swamp buggy racing is unlike any other type of off-road racing. The majority of the course is covered in 17-19 inches of water, and there are two “sippi” holes that are 5½ feet in depth. Jeep-class rigs become almost totally submerged in the sippi holes, and often only the head of each passenger and the vehicle’s rollcage is visible as the rig powers along under water. To keep things running while submerged, the rigs are completely waterproofed. How this is done is fascinating and ranges from standard preparation to homegrown tricks.We had a chance to look at a variety of competitors and found that each driver’s individual ap-proach varies, but the goal is the same -- seal up all of the components so that the machine will run while under water. We also took a look at the faster classes of buggies that don’t become completely submerged but do have to deal with vast amounts of water spray as they skim over the water at high speed.
In the end, the extreme waterproofng that the swamp buggy racers use can serve as a guide for those of us who put our rigs in water, either on purpose or inadvertently.
Silicone, and other types of sealants, is used liberally to keep water out of components. This is the carb on Wayne Miller’s “Phantom” Jeep and as you can see it’s slathered in silicone. Many drivers apply silicone to the inside of the air intake tube at the carburetor before clamping the two together to ensure a waterproof seal. It may not look pretty, but it works. The fuel cell feeding the carb gasoline also undergoes a total sealing to ensure water doesn’t intrude, as does not-often-thought-of things like the engine oil dipstick tube.
Distributors are used on some of the engines and the sealing procedure varies. In the Jeep class, where the distributor can be completely submerged, drivers seal the distributor to keep water out, like the one shown. This unit has been slathered with inexpensive duct sealant. In the faster classes that do not submerge the distributor, it’s often covered by a tire inner tube that is left open at the bottom so the distributor won’t sweat.
This Jeep-class rig has a water break in front of the engine pulleys. At speed, this device helps keep water from forcing its way around the timing gear gasket and into the engine.
As a rule, the engine air intake needs to be at the highest point possible on a rig. Here are two examples found on Jeep-class machines.
On the top is a homemade box made from 1⁄8-inch-thick sheetmetal and air duct vents. Inside is a paper filter and it works in conjunction with the box to trap moisture from water spray. Down is an intake that is recessed in the custom roof of a rig.
Keeping water out of the faster buggies with sealed bodywork can be as simple as using a chunk of rubber from an inner tube. This chunk was used to seal the area where an axletube traveled through bodywork.
The go-fast buggies are generally designed with the driver positioned ahead of the water spray. This cockpit area rarely becomes submerged, so there isn’t a significant emphasis placed on sealing things like gauges -- a clear plastic bag and zip ties can do the trick. However, gauges in the Jeep-class rigs will often become submerged in the 5½-foot-deep sippi holes, so drivers will either mount them high in the rig or slather them in silicone to prolong their life.
Some of the go-fast buggies that have enclosed bodywork are equipped with air intake lines that stretch to the front of the rig so the engine can get an ample supply of clean, steam-free air. Eddie Chesser’s rig is fitted with five 4-inch tubes that connect to the aluminum air intake box. This box was custom made to fit inside the rig’s bodywork.
Because the axles are submerged in cool water during the race, many of the Jeep-class buggies don’t use venting on the differentials because they don’t generate enough heat to warrant a vent. However, the differentials are enclosed on the buggies with full bodywork, so each is typically fitted with a filtered vent tube.
Exhaust pipes in the Jeep class are typically routed straight up from the engine above the water line so as not to allow water to enter the engine and to allow the engine to freely exhale.
Some race vehicles use a distributorless ignition system. This system utilizes a crankshaft gear and a crank sensor, which is impervious to water. Some teams use a cover of some sort to keep the crank sensor from being damaged or clogged. The electronics on Clay Madl’s Jeep-class rig are mounted in a waterproof case that is mounted high on the cowl. All of the areas where wires pass through the case are sealed with silicone to prevent water intrusion.
The go-fast buggies typically mount the engine radiator at the rear of the machine, while the Jeep-class vehicles tend to use one of two locations. Some use a small radiator at the front of the rig in the standard mounting location, while others mount a fullsize radiator high on the rear of the rig. We’re told that the downside to the small, front-mounted radiator is that engine runtime is limited due to heat buildup from the high rpm’s the mandatory four-cylinder engines turn during racing.
Some Jeep-class rigs use a manual rack-and-pinion steering setup. Even a homemade boot, pictured here, can help keep water out. Even with the boot, racers told us that they have to disassemble and clean the system after each racing weekend because water and sand gets in. On that note, we’re also told items like the starter are often disassembled and cleaned after a weekend of racing. One driver told us that he can get about two years of service from a starter by keeping it clean. Naturally, all the lubrication fluids are drained from driveline components after every racing weekend as well.
Want More Swamp Buggy Stuff?
Stayed tuned to Four Wheeler for in-depth (no pun intended) coverage of the World Famous Swamp Buggy Races from Naples, Florida. The photos and tech from this one-of-kind event will fascinate you!