Car Craft has always been about the underdog. Anybody with a water-cooled checkbook can go out and buy a supercharged LS9 and make big power. That leaves the rest of us looking for a less-expensive route. Our sojourn started many moons ago with a fairly simple plan: see how cheaply we could stuff a small LS engine in the Orange Peel Chevelle. We bought what we were told was a used 5.3L only to discover we had been 4.8L hoodwinked. Despite its runt status, we persevered with bolt-on parts and eventually a tickle of nitrous, and our littlest warrior just keeps making power.
In the Dec. 2016 issue, Car Craft showed you how the 4.8L made 430 hp with help from a set of mildly ported heads from Richard Reyman and his crew at West Coast Racing Cylinder Heads (WCRCH). That's when comrade/tech geek Richard Holdener said, "Hey, let's bolt a blower on it and see what it'll do." We applied boost with a Vortech carbureted blow-through, V-3 Si series supercharger kit that bolted right on the front of our LS using the MaxFuel Power Hat. Because the cylinder heads bumped the compression up to 10.0:1, we ran the engine on 110-octane Rockett Brand gasoline and were surprised by the results: this seriously used, 293ci motor thumped out 636 hp at 11 psi of boost, using a 7.5-inch ATI crank pulley and a CSU-prepped blow-through carburetor. The boost and horsepower were still climbing when we shut the test down, mainly to preserve those cast pistons. We weren't concerned as much with the effect of cylinder pressure as we were with the g-forc e loads on the pistons above 6,500 rpm. Plus, we wanted to test the engine in our Chevelle.
The most complex part of the entire installation is drilling and adding a drive pin between the Summit balancer and crank snout because LS engines don't come with a woodruff key. This pin prevents the balancer from spinning on the crank snout because larger blowers can demand 50 hp worth of load that pulls right off the crank snout. The blower we used in the car was the same supercharger—but with a completely different drive assembly—utilizing Summit Racing's 10-rib SFI balancer and Billet Front Drive accessory assembly. Its kit includes the bracket, alternator, and power-steering pump. We added an early Camaro-style water pump and a drivebelt to complete the system.
We had to cut a small clearance hole in the right-side, inner wheelwell to clear the edge of the blower. Once the blower and accessory drive were bolted in place and the radiator was refilled, the last part of the installation required some fabrication. The blow-through kit comes with a cone-shaped air filter, but we didn't want the air cleaner sitting right on top of the passenger-side header. We dug up a length of wire-reinforced, 4-inch-diameter, brake-duct hose that we adapted to the air filter. We placed the filter at the firewall, where our cowl-induction hood can supply plenty of cool air.
Back at Westech, the first pull was extremely rich, so we pulled the jets down to more manageable 75s in the primary and secondary. That left the transition from part throttle to wide-open throttle (WOT) still very rich, but once the boost came up, the air/fuel ratio eventually stabilized at 11.7:1 at peak power. For timing, we eventually settled on 26 degrees of timing, and our first full pull through 5,500 rpm produced 5 psi of boost and 475 hp. Things were looking good.
Eric says our TH200-4R automatic and small tires will generally devour 100 hp on its way to the rear wheels. Calculating back from our 632-flywheel-horsepower peak at 11.7 psi, we set our sights on 532 rwhp. With our first pull on the chassis dyno showing 475 hp at only 5 psi boost, we were very encouraged, despite our engine not revving past 5,500 rpm.
Westech's Eric Rhee's tuning experience came to the rescue. In the past, he's seen digital rev limiters become confused, causing ignition cuts at lower than specified engine speeds. We had set the MSD box at 6,800 rpm, but the limiter shut the engine off below 6,000 rpm. Rhee raised the limiter speed to 8,000 rpm, and on the next test, our Tiny Dancer twirled right over 6,500 rpm and peak power jumped to 502 hp at 6,400 rpm. However, we were only able to make 6 psi boost on the stock pulleys. Vortech's Jimmy Martz told us its self-contained blowers are limited to 52,000 rpm of blower speed. He calculated that with our stock pulleys, we were turning 46,800 rpm on the supercharger at an engine speed of 6,500 rpm, so we can safely change pulleys for more blower speed to make more boost. In the meantime, we will see what kind of performance we can achieve with 91-octane gasoline, including a Snow Performance water/methanol injection kit. We'd really like to see 500 hp at the wheels on pump gas.
Vortech offers a blow-through LSx supercharger package that includes the self-contained V-3 Si supercharger. Self-contained means the supercharger holds its own lubrication and does not use engine oil. This makes installation much easier because no return line to the oil pan is required. We started by bolting our engine to Westech's SuperFlow engine dyno. With help from Richard Holdener, the Vortech V-3 blower pushed the little 4.8 to 632 hp and 519 lb-ft of torque using 11 psi boost pressure on Rockett 100-octane race gas. After removing the accessory drive and balancer, we drilled a longitudinal slot in the crank using Vortech's drill guide to pin the balancer. This ensures the harmonic balancer does not spin on the crank snout under blower load. We then installed Summit Racing's SFI balancer using the dedicated installer tool. This balancer is configured with a Corvette depth for the accessory drive and offers a three-bolt flange for the blower crank pulley. When mounting the supercharger to the engine installed in our 1966 Chevelle, we discovered the inner fenderwell interfered with mounting the supercharger. We cut a hole in the inner fenderwell to get the blower to fit. The hole didn't need to be quite so large, so we'll eventually clean this up and create a clearance bubble for the supercharger. Summit Racing sells a very nice LS engine accessory drive that includes the brackets, alternator, power-steering pump and pulley, and fasteners. Summit Racing also provided a Corvette/Camaro-style water pump to match the drive assembly, so the only other pieces needed are a Gates tensioner and belt to complete the installation. We opted to not use the power-steering pump because our Chevelle has manual steering. Making big power requires a good fuel-delivery system. While this Phantom in-tank fuel-delivery system isn't necessary for a carburetor, we have plans to try a self-learning throttle-body system on this engine and it will demand a system like this. We'll also use an Aeromotive X1 regulator that easily converts between carb and EFI fuel pressure. Here's the completed installation, including our temporary 4-inch hose that placed the air cleaner directly underneath the Chevelle's cowl-induction hood. Also note the Vortech MaxFlow Power Hat that acts like a diffuser to even the pressure across the top of the carburetor. This was used on both the engine and chassis dyno tests. Our Chevelle performed extremely well on the chassis dyno at wide-open throttle (WOT), but it's still too fat at mid-throttle. The biggest challenge from here will be tuning the carburetor to be properly lean at part throttle and still deliver at rich air/fuel ratios at WOT. Engine Dyno Test
Our 4.8L engine in this configuration used a stock 4.8L short-block with 140,000 miles on the odometer. The heads are stock castings that were mildly ported by WCRCH. The compression ratio is 10.0:1. The cam is a Comp 269Lr (see specs in chart) with an Edelbrock Performer RPM dual-plane intake, QuickFuel 650 BAN blow-through carb, and Hooker 1-3/4-inch headers with open exhaust. Note that peak torque occurred at 6,200 rpm, and we stopped the test at 6,500. It's likely the peak horsepower would occur somewhere around 7,500 rpm, but we did not want to spin this cast-piston engine that high.
| RPM | TQ | HP | Boost |
|---|---|---|---|
| 3,500 | 387 | 258 | 3.7 |
| 3,600 | 382 | 262 | 4 |
| 3,700 | 382 | 269 | 4.2 |
| 3,800 | 386 | 279 | 4.3 |
| 3,900 | 392 | 291 | 4.5 |
| 4,000 | 401 | 306 | 4.8 |
| 4,100 | 409 | 319 | 4.9 |
| 4,200 | 418 | 334 | 5.1 |
| 4,300 | 427 | 350 | 5.3 |
| 4,400 | 437 | 366 | 5.6 |
| 4,500 | 446 | 382 | 5.9 |
| 4,600 | 452 | 396 | 6.1 |
| 4,700 | 458 | 410 | 6.3 |
| 4,800 | 465 | 425 | 6.6 |
| 4,900 | 471 | 440 | 6.8 |
| 5,000 | 477 | 454 | 7 |
| 5,100 | 483 | 469 | 7.3 |
| 5,200 | 490 | 485 | 7.6 |
| 5,300 | 494 | 498 | 7.9 |
| 5,400 | 496 | 510 | 8.3 |
| 5,500 | 500 | 523 | 8.6 |
| 5,600 | 504 | 537 | 8.9 |
| 5,700 | 508 | 552 | 9.1 |
| 5,800 | 512 | 565 | 9.4 |
| 5,900 | 515 | 578 | 9.6 |
| 6,000 | 517 | 590 | 9.9 |
| 6,100 | 518 | 602 | 10.2 |
| 6,200 | 519 | 613 | 10.7 |
| 6,300 | 519 | 623 | 11.1 |
| 6,400 | 518 | 631 | 11.4 |
| 6,500 | 514 | 636 | 11.7 |
Chassis Dyno Test
The rwhp test was also performed at Westech. The engine was configured with the same Vortech supercharger but fitted with a smaller crank pulley, which lowered the boost curve. The point worthy of note is the excellent rwhp numbers relative to the low boost level.
| RPM | HP | TQ | Boost |
|---|---|---|---|
| 3,132 | 223 | 374 | 1.6 |
| 3,216 | 234 | 382 | 1.7 |
| 3,467 | 254 | 386 | 1.9 |
| 3,552 | 260 | 385 | 2 |
| 3,636 | 266 | 384 | 2.1 |
| 3,805 | 279 | 386 | 2.4 |
| 3,978 | 297 | 392 | 2.6 |
| 4,154 | 314 | 397 | 2.8 |
| 4,332 | 332 | 403 | 3 |
| 4,509 | 350 | 408 | 3.3 |
| 4,693 | 368 | 412 | 3.6 |
| 4,878 | 390 | 420 | 3.9 |
| 5,065 | 412 | 427 | 4.1 |
| 5,256 | 432 | 432 | 4.5 |
| 5,446 | 450 | 434 | 4.8 |
| 5,636 | 463 | 432 | 5.1 |
| 5,824 | 474 | 427 | 5.3 |
| 6,011 | 483 | 422 | 5.4 |
| 6,195 | 495 | 420 | 5.6 |
| 6,377 | 502 | 414 | 5.7 |
| 6,552 | 496 | 397 | 5.5 |
4.8L Tiny Dancer Bibliography
*Summer edition of Engine Swaps, Budget LS Engine Swap
*Nov. 2013, pg. 40 "Moving Cheap (Tiny Dancer) Part I," 12s on Nitrous
*Dec. 2013, pg. 44 "Tiny Dancer Part II," 11.40s on Nitrous
*Jan. 2014 pg. 42 "Tiny Dancer, Part III," Suspension Changes
*Dec. 2016, pg. 14 "Underdog Bites Back," 430 NA HP Dyno Test
Parts List
| Description | PN | Source | Price |
|---|---|---|---|
| Vortech V-3 LSx supercharger kit | 4GX218-020L | Jegs | $3,992.99 |
| West Coast Racing ported 5.3L heads | Call | WCRCH | $1,062.00 |
| Summit SFI LS harmonic balancer | SUM-C2501 | Summit Racing | $189.97 |
| ARP crank bolt | 234-2503 | Summit Racing | $34.57 |
| Comp hyd roller cam 269Lr | 54-456-11 | Summit Racing | $377.97 |
| Hooker 1-3/4-inch coated headers | 2289-1HKR | Summit Racing | $763.95 |
| Edelbrock Performer RPM dual plane | 71187 | Summit Racing | $316.84 |
| QuickFuel 650-cfm blow-through carb | SS-650-BAN | Summit Racing | $776.95 |
| Summit LS billet front drive | CSUMLS103 | Summit Racing | $570.82 |
| AC Delco 2000 Camaro water pump | 19256263 | Summit Racing | $218.97 |
| Contitech 6-rib serpentine belt | PK060730 | Summit Racing | $14.97 |
| Gates tensioner | 39194 | RockAuto | $43.89 |
| Mr Gasket straight thermostat housing | 2671 | Summit Racing | $30.57 |
| MSD LS1/LS6 ignition box | 6010 | Summit Racing | $364.95 |
| Rockett Brand 100-octane racing gas | 100 Octane | Call dealer | Call dealer |
| Aeromotive Phantom 340 pump kit | 18688 | Summit Racing | $463.97 |
| Aeromotive X1 regulator | 13304 | Summit Racing | $195.97 |
| Summit LS balancer puller/install tool | SME-K-906008 | Summit Racing | $149.97 |
