by Jay Storer
The difference between a street rod and a hot rod is pretty subjective, but if there's one single thing that universally raises the style temperature and a hot rodder's pulse at the same time, it's a powerful engine. Thousands of rods today have engines way more powerful that what used to be the norm for such cars in the past, and all of them look pretty at the same time, decorated as they usually are with chrome and polished components. Factory crate engines have made reliable engines with good power as close as your dealer's parts counter, do you don't have to build your own. Randy Clark of Hot Rods & Custom Stuff likes to think a little "outside the crate." When it came to powering our Deuce our Deuce highboy, Randy selected an LS1 engine build by Gen III Performance, a 4L60-E automatic transmission from TCI Automotive, and a 9-inch Ford-based rear end built by Currie Enterprises.
So yes, we have a strong and uncommon engine in our dream Deuce highboy, but what has always been the focus of the STREET RODDER Road Tour is demonstrating to people all across the country how fun, exciting, and yet practical a state-of-the-art street rod can be. The 25,000-mile tour on a hectic schedule is no place for an iffy drivetrain.
For those not into the little details of engine history, Gen III stands for what is considered the third "generation" of small-block Chevy V-8 engine design. Introduced in the 1997 Corvette as the LS1 version, this was a small-block that shared virtually nothing with its predecessors. This evolved into the LS6 version in 2000, which had a number of small changes. All of the production LS1/LS6 engines had been 345 ci in size, with relatively high compression, good engine management, and other factors that made them strong runners. Scott Turvey, owner of Gen III Performance and builder of our Highboy's powerplant says, "They're so good to start with that they can make 400 hp just by looking at them sideways."
That should be enough to get any rodder's attention, but this is a very modern, computer-controlled engine "missing" the things most rodders are familiar with, like a carburetor and distributor. Thus, many have shied away from using such an engine outside of its natural environment in a new production car. Modifying the GM computer and dealing with OEM wiring harness isn't easy even for those who are used to such magic. Enter: Scott Turvey.
After 23 years in the computer world, Scott spent time working for a company building LS1 engines for off-road machines, learning what it takes to make both power and durability from them, as well as how to program them to run outside the OEM environment. The latter part of that equation intrigued him as much as the hardware.
Scott knew plenty of people who did CNC machining, had absorbed the engine-building knowledge of the Gen III design, knew performance car shops all around the San Diego area (including Randy Clark's), and knew computing inside and out, so the opening of his own Gen III Performance shop became a forgone conclusion. Gen III makes very high performance versions of the LS1/LS6, but also tames and controls them with electronic fuel injection and management. Each engine he sells comes with the dyno time to set it up specifically for you exact application.
Gen III sells engines that range in size from 345 ci like ours to about 100 ci more that that. Given how this one sounds, we can't imagine anyone using a bigger version! There was a time (the '60's) when the phrase "all-aluminum Chevy V-8" meant the powerplant of a rare ZL-1 Corvette, Can-Am motor, or something in an altered-wheelbase matchrace Funny Car, but ours is based on a readily available engine that offers the triple crown of performance, light weight, and drivability.
What's on top of an engine assumes a high level of importance in conservative hot rodding circles. We like V-8 engines to look like the traditional ones we grew up with. The LS1/LS6 looks quite different because there's no distributor, there are eight ignition coils, there's tons of hose and wire, and the stock plastic intake manifold is less than appealing. Gen III uses polished or chromed Weiand aftermarket intake manifolds on some models, and billet valve covers on all models, to dress things up a bit. But for the ultimate in turnable performance and inspiring appearance, STREET RODDER and Randy Clark decided to go all the way: using Scott's billet throttle bodies. It is Scott's combination of all these pieces with the engine management equipment and his tuning that makes all this horsepower user-friendly and drivable. He has developed a base program that works with each of his engine packages, and he tweaks from there to personalize for each customer. We can't wait to get ours on the road!
All this power would be of little use if it couldn't be harnessed. You would expect that the task of surviving and performing behind an engine like ours would require a radically tweaked transmission with a benchful of expensive specialty internals and some kind of race-style high-stall converter that is unpleasant to use in normal driving.
Ten year ago, that would have been the case. Luckily, the Detroit technology that has brought our engines into the electronic age has done the same for some pretty cool transmissions. In the General Motors catalog, the 700-R4 has been the transmission of choice for overdrive automatics for some years now, but without considerable work it may not be able to handle really big horsepower.
The recommendation for the Road Tour Deuce from the experts at TCI Automotive was the relatively new 4L60-E. The "E" in this instance stands for electronic and, as has been the case with computer-controlled engines like the LS1, some enthusiasts are reluctant to deal with the technology. If the average rodder is nervous about trusting his powerplant to one computer, it'd only make sense he'd be unsure about having two computers on board!
God bless or aftermarket manufacturers and the pioneering tinkerers who find all the "way-arounds" we've been looking for, because the 4L60-E is worth having, especially when a TCI-equipped unit like ours is capable of handling up to 800 hp. In its stock environment, an electronic transmission is controlled by a computer in the car.
What TCI has done is work with a major aftermarket engine-controls company to develop a stand-alone computer and software for transmissions like the 4L60-E. But ease of installation is only half the fun of using our 4L60-E. The TCU supplied by TCI is set up to run out of the box, but is also fully programmable by the user. With a laptop computer hooked up to the TCU and a savvy passenger with you to hold it and make corrections to the program, you can drive your car while your passenger "tunes" your transmission! It may sound scary to those of us who are megabyte-challenged, but TCI has given all this a pretty serious think.
Among the various transmissions parameters that can be changes are the shift rpm's, hardness of shifts, converter lockup timing, and such subtle details as dialing the amount of lockup delay after shifts have been made. TCI has assured us that their system is "dummy proof." There is always a basic program that remains in the TCU and you can revert to that at any time.
In addition to the transmission itself, a torque converter is needed. TCI recommends that you always consult one of their tech guys before ordering a transmission, so they know how your engine is equipped, what kind of driving you intend to do, and what weight and type of car it's for. The biggest engine factor when choosing the right torque converter is the camshaft profile, so have your specs ready when you call TCI. What we're using in our roadster is the 12-inch, 2,400-rpm stall speed Breakaway model converter with lockup function, but your needs may be different. One last thing, the 4L60-E also has the 3.06:1 low gear, just like the 700-R4, for good "gow" from the stoplights.
So we have a powerful engine tamed to our will by a computer, and a stout automatic transmission also controlled by a "black box" to transfer the load rearward. What the heck to do beyond that? While you can get away with more moderate drivelines when you have a lesser-performance powertrain, we had no choice but to go with very heavy-duty equipment at this end of the car.
Currie Enterprises has made a very successful business out of building rearends, especially the Ford nine-inchers, and they have been gradually manufacturing more and more pieces for these rearends. Our unit consists of a beautifully polished aluminum center housing fitted with steel axle tubes with Ford Torino-type axle ends. These ends are important because many aftermarket rear disc brake kits are designed to bold to that style housing. Currie calls it their "street rod rearend" because of its obvious visual appeal. The Currie Performance high-strength axles are of the 31-spline type that can handle more power than the more-common 28-spline axles. Our differential is a real Ford unit, but equipped with a TSD limited-slip so both rear tires can get a bite if they need to, and the diff also has a Currie polished aluminum pinion support that uses a larger-than-stock pinion bearing. We're utilizing a set of 3.70 gears because we have overdrive and tall rear tires. Check the sidebar on gearing to help you choose something for your application.
Installing an engine and transmission into today's reproduction street rod frames is generally quite easy. The available frames are made with all the mounts in place for the engine/trans combo you specify. Our roadster was no exception to this kind of shopping, except that this was the first Deuce Steel chassis HR&CS has build for an LS1 engine.
A stock LS1 long-block and an empty transmission case were mated and dropped into the chassis while it was still in the frame fixture in order to get an idea of where the engine mounts would need to be. Randy decided to adapt standard small-block Chevy V-8 engine mounts to the LS1 aluminum block. The frame mounts were moved rearward on the frame a little over 2 inches, and a thick, roughly triangular aluminum plate was bolted to the LS1 block mounting holes.
The transmission mounting situation was simpler. The design of the HR&CS's X-member allows considerable flexibility for locating the transmission mount. Since the Deuce Steel frame rides pretty low, part of Randy's chassis design is to have the engine and transmission ride higher than normal within the frame- this maintains acceptable ground clearance and keeps the side view of the car from showing much of anything hanging down below the rails. With the powertrain at this level, a standard GM rubber mount under the trans is at the right height for a flat steel plate to span across the two lower-front legs of the X-member to carry it. Simple is good!
The typical build process in a professional street rod shop is to put the whole car together in the raw, that is, with nothing painted. Everything that requires cutting, welding, drilling, etc. is done at this stage. At the risk of oversimplifying the process, the body parts are fitted, the plumbing is laid out and various subassemblies like heat/AC, steering column, and other details are tried out and fitted to the car. To continue the outline for the construction, the car is completely disassembled after all of this "fitting" work has been done.
At this point, all of the various parts are sent off for chrome, polishing, powdercoating or painting. When everything is back in-house, very careful assembly work mates all of the pieces together without scratching the paint. At that point, you have an almost-finished car.
The only big items that remain to be done from then on are the interior work and the wiring, and the pros are experienced in working around a painted car while finishing it off. Whether you have a shop like HR&CS assemble a car for you, or you purchase the components and put it together yourself, you have the special thrill of being part of the design and construction of you own personalized car.
Some people collect stamps for a hobby, knit, paint landscapes, or just keep the couch from flying away during TV sports, but street rodders have the uniquie pleasure of actually being able to drive their "hobby" around!