It must be based on a 6.5L-powered, full-size GM truck
It should run in the Diesel Truck (DT) class and our 6.5L turbo will put it in engine class size B.
The body must be absolutely factory original with no aerodynamic upgrades
The 6.5L engine must be in stock original configuration (stock block, crank, rods, pistons, heads, cam, etc)
The truck must be presented in a perfect, original condition, inside and outside. Nothing less than show quality would do.
Craigslist to the Rescue
Bill Heath was quite concerned about the time and effort that might be consumed by searching for a vehicle with the exact specifications that the team felt would be the optimal race truck. In November 2007, the search began. As it turns out, finding just the right vehicle was probably the easiest thing that would happen in the course of bringing the dream into existence. Within days of posting the vehicle's specifications on the Internet, using the website, Craigslist, a response arrived for exactly the vehicle they wanted. Amazingly, only 70 miles away in Othello, Mr. Kent Pearson - the original owner of a Chevy with 288,000 miles on it - had just such a vehicle for sale. He was thrilled to know his truck would soon be out on the Salt Flats and he plans to make the trip to watch it go for a record in August.
For his part, Bill Heath is proud that the truck is a bonafide Chevy 6.5L diesel:
"The truck that we are using is a truck that was bought brand new with this [6.5L] engine. We bought it from the original owner... It is not a conversion from gas or anything like that."
In addition, Heath Diesel is doing everything they can, as they pursue the land speed record, to stay true to the stock nature of the truck.
"We want it to look like real truck; we want it to not be modified in terms of body configuration and it will not be. It necessarily has to have safety devices in it and it has to be on special wheels and tires for speed and it is lowered, but it is a real truck. It's going to have radio, heater, tilt steering - all that stuff. It even has a CB radio in it so that the driver will be able to monitor the frequencies used by the Bonneville Race officials."
Recipe for a Land Speed Racer.
Preparing any racer for competition at the Bonneville Salt Flats involves working through a long list of upgrades in order to meet performance and safety requirements. In building our race truck, the first step we took was to build the roll cage.
Heath Diesel Land Speed Vehicle Roll Cage
This protective cocoon had to be constructed of heavy, 0.134-inch wall tubing configured to meet Southern California Timing Association (SCTA) / Bonneville Nationals Inc (BNI) regulations. These folks are serious about their safety regulations and about enforcing them. Heath chose to build the racer on an extended cab, short-box GM platform. This allowed for a very roomy cabin in which to build the cage assembly and, perhaps, a slightly more aerodynamic body shape than a regular cab truck. John Raney of Yakima fabricated the very robust cage to specifications.
The racer will run in the DT (diesel truck) class which does not allow any aerodynamic improvements. The body must be stock. A bed cover is allowed, so the guys at Heath built a special, two-piece rigid cover that fits below the top rail of the bed, per regulations. In an effort to reduce aero-drag, they employed drop spindles and special, shorter-than-stock front coil springs. These changes combine with the 26-inch tall Good Year Land Speed Racing tires to put the factory air dam about two inches off the surface of the salt.
In the rear, Heath de-arched the rear springs and this, combined with the added weight of the dual batteries, water injection storage tank and 28-inch tall Good Year Land Speed Racing tires, brought the rear ride height down. With these combos, the truck is as low as they could get it and still maintain a nose down rake of one-and-a-half degrees.
While the extended cab is full of roll cage, Heath worked to maintain the factory dash panel, door panels, rear cab wrap around components, headliner and carpet. Of course the factory seats had to go in favor of the cage and race seats - one for the driver, Bill Heath and a second for a passenger when the truck is not racing.
The project truck came with a full compliment of farm-dents, those many little badges it earned while serving Mr. Pearson. Brian Maybee, owner of McIntosh Auto Body in Ellensburg, spent many hours making the racer straight and smooth before lavishing it with a beautiful paint finish.
When the McIntosh crew finished, new bumpers, grill, headlights, signal lamps, tail lamps, side moulding and wheel trim were installed. The completed truck looks like new and then some. All these new trim pieces were supplied by University Auto Center the GM dealer here in Ellensburg.
Bill explains that the "racer is a licensed, street legal truck that will be driven to various car shows in the area. The original owner, has been by our shop on several occasions to check progress on his baby. He is an enthusiastic supporter of our efforts to set a land speed record with his old truck and we have promised him rides in it when we are done - hence the passenger seat. This is a real, honest-to-goodness, full-sized GM 6.5 truck and not a down-sized S-10."
Heath Diesel Land Speed Vehicle
Heath Diesel Land Speed Vehicle
The Engine
The powerplant for the Heath racer is based on its original engine. It has been rebuilt by Heath to exacting factory dimensions and clearances, using the original block, rods, cam, cam followers, heads, etc. In order to assure peak diesel-combustion efficiency with the 6.5's Recardo-Comet type combustion chamber, the compression ratio is factory stock at 21.3:1.
Heath treats the block to a process designed to add strength to the cylinders and crankcase. The coolant jackets are filled with a type of hydraulic concrete to within 2.4 inches of the deck surface. The remaining space allows sufficient room toward the top of the cylinders for coolant flow and for its distribution into the cylinder head above them. Filling the coolant jacket space like this contributes substantially to the overall rigidity of the cylinder barrels and helps to tie them to the crankcase below, contributing to the overall strength of the block. Perhaps you are thinking that this will cause an overheat condition, Bill Heath's experience has been that this concern is unfounded. All of Heath's 6.5s have been built using this same process - for many years - in all of their hard working trucks and Suburbans.
The cylinder heads are stock 6.5 units that have been outfitted with the larger valves originally used in the 1982 6.2 engine.
The intake and exhaust ports are treated to a simple pocket-porting' or clean-up in the bowls and valve guide bosses which is standard.
The main caps are factory issue but held in place with Heath's main stud kit instead of the factory-issue bolts. No girdle is employed, only the special studs. The only other special fasteners employed in the engine are the cylinder head studs. Fel Pro gaskets are used throughout.
The pistons are replacement units made by Mahle. They have been treated to a special ceramic coating process that includes one type of coating on the piston crown, another on the exterior skirt surfaces and a third inside the piston. These special piston coatings, along with the coating of many other external engine components, were all applied by Brad Gua's Performance Coatings of Seattle, WA. These coatings help prevent heat-damage to the piston bodies and keep the engine alive for full throttle speed passes across the salt.
Heath opted to use the new SCAT 9000 series crankshaft in this engine. Bob Jones of SCAT suggested his company's new 9000-series crankshaft in the racer and, since the original had 288,000 miles on it, this seemed good advice to Bill. Heath Diesel has run SCAT's crankshafts in a number of its daily drivers and, so far, have been pleased with them. They also employed the new Fluidamper harmonic damper, feeling that this upgrade is particularly meaningful given the elevated RPM the racer will see. All precision machine work and balancing has been performed by Rich Eims, owner of Joe's Grinding in Yakima.
Because the 6.5 racer is going to be spun up to 5300 RPM and will spend the majority of its time, on these speed runs, pulling at between 4600 and 5300 RPM in top gear, the engine will produce an exhaust flow increased over stock levels by approximately 50 percent at peak RPM. The factory exhaust manifolding, plumbing and single turbocharger would impose a tremendous and costly restriction to exhaust flow at these higher RPM. In order to reduce restriction to exhaust flow and to improve turbocharging efficiency, a set of individual turbocharger headers were designed for the engine. John Raney to the rescue again! He built a beautifully crafted set of headers for our very unique application. Each of these headers mounts a turbocharger, one on each side of the engine. These two turbos feed a common plenum atop the factory L65 intake manifold casting. The drive-pressure required to spin the turbos to produce the desired boost pressure is relatively low which helps to establish a more efficient boosting of the engine.
Cooling the intake charge-air is handled by one of the new Heath/Snow Performance Stage-1 water injection intercooling systems. Water injection intercooling is the preferred intercooling method for the 6.5 and the Heath/Snow solid-state controller provides precise metering and maximum intercooling efficiency. Rules prevent the use of methanol, so pure water is the racer's intercooling diet on these speed runs. In fact, in this particular racing class, no supplementary fuels, such as propane, are allowed. The truck will run on event-supplied diesel.
The fuel injection system is comprised of an off-the-shelf 5521 Stanadyne injection pump and Heath's HO (High Output) fuel injectors. The injection pump is supplied by a special 6.5 version of FASS system, mounted in the bed of the racer and pulling from the factory 26-gallon fuel tank.
Unrestricted and highly filtered airflow into our engine is handled by the new Heath Cold-Air Intake system. Each turbo downpipe will exit behind the front wheel on each side.
Naturally, the truck is equipped with every Heath upgrade, including a special Land Speed version of the Max-E-Tork PROM. As has been pointed out, the engine is configured to allow engine RPM up to 5300. In addition to this modified limit, the special programming features totally revised fuel and start-of-injection timing schedules as well as transmission programming to cause full throttle upshifts at 5000 RPM (the 4L80E shifts into fourth gear at 122 MPH). Future plans call for switching over to a five-speed manual transmission to reduce that parasitic loss caused by the automatic transmission.
Because Heath team is not certain how fast its critter will run, they are prepared to make any axle ratio changes necessary to suit the need. Bills says, "We felt it best to change from the factory rear axle to one that would facilitate speedy ratio changes."
It happens that the rear axle assembly use in the 1976 Lincoln, is perfectly suited. In addition to having the Ford nine-inch drop in gear setup, this Lincoln rear is the correct width and even has a five-on-five wheel bolt pattern to match the factory half-ton, two-wheel drive Chevy. Bill plans to bring a number of ratios with him to the Salt Flats so that they can dial-in our final drive.
The Toyota Hilux engine has changed many times since 1968 when the Hilux first debuted. Back then, it was powered by a small, 1.5 litre 4-cylinder. It has since evolved many times over with some models maintaining a 4-cylinder engine although now they're bigger, more powerful and even turbo or diesel powered (or both) while some models made a jump to larger displacement V6 engines. This article will provide a brief timeline into the history of the Toyota Hilux engine.